Implement Bazel Clang toolchain

Fix a bunch of warnings
Add numbers parsing
2025-07-12 17:11:54 +02:00 · 2025-07-06 17:05:36 +02:00 · 2025-07-04 20:44:04 +02:00 · 2025-07-04 18:22:03 +02:00 · 2025-07-03 18:35:25 +02:00 · 2025-07-03 18:34:45 +02:00
74 changed files with 9437 additions and 313 deletions
--- a/.bazelrc
+++ b/.bazelrc
@ -1,19 +1,14 @@
+common --registry=https://bcr.bazel.build/
+common --registry=https://bazel.stevenlr.com/registry/
+
 startup --windows_enable_symlinks
 build:windows --enable_runfiles=true

 build --enable_platform_specific_config
 build --build_python_zip=false

-build:windows  --extra_execution_platforms=//:x64_windows-clang-cl
-# @Todo(bazel) We should be able to use @local_config_cc...
-build:windows  --extra_toolchains=@@rules_cc++cc_configure_extension+local_config_cc//:cc-toolchain-x64_windows-clang-cl
-
-build:linux    --repo_env=CC=clang
-
-build:windows  --cxxopt=-Xclang=-std=c++23
-build:linux    --cxxopt=-std=c++23
-
-build --cxxopt=-Wall
+build --features=c++23
+build --cxxopt=-Weverything
 build --cxxopt=-Wno-c++98-compat
 build --cxxopt=-Wno-c++98-compat-pedantic
 build --cxxopt=-Wno-pre-c++17-compat
@ -26,21 +21,7 @@ build --cxxopt=-Wno-global-constructors
 build --cxxopt=-Wno-unsafe-buffer-usage
 build --cxxopt=-Wno-covered-switch-default
 build --cxxopt=-Wno-unused-command-line-argument
-
-build:windows_san --config=windows
-build:windows_san --copt=-fno-sanitize-ignorelist
-build:windows_san --copt=-fsanitize=address
-build:windows_san --copt=-fsanitize=undefined
-build:windows_san --copt=-fno-sanitize-recover=all
-build:windows_san --linkopt=clang_rt.asan_dynamic-x86_64.lib
-build:windows_san --linkopt=clang_rt.asan_dynamic_runtime_thunk-x86_64.lib
-
-build:linux_san --config=linux
-build:linux_san --copt=-fsanitize=address
-build:linux_san --linkopt=-fsanitize=address
-build:linux_san --copt=-fsanitize=undefined
-build:linux_san --copt=-fno-sanitize-recover=all
-build:linux_san --linkopt=-fsanitize=undefined
-build:linux_san --linkopt=-fsanitize-link-c++-runtime
+build --cxxopt=-Wno-padded
+build --cxxopt=-Wno-weak-vtables

 test --test_output=errors
--- a/.clang-tidy
+++ b/.clang-tidy
@ -21,3 +21,4 @@ Checks:
  - "-cppcoreguidelines-pro-type-union-access"
  - "-*-copy-assignment-signature"
  - "-*-unconventional-assign-operator"
+  - "-readability-math-missing-parentheses"
--- a/BUILD.bazel
+++ b/BUILD.bazel
@ -13,14 +13,3 @@ license(
    package_name = "ASL",
 )

-platform(
-    name = "x64_windows-clang-cl",
-    constraint_values = [
-        "@platforms//cpu:x86_64",
-        "@platforms//os:windows",
-        # @Todo(bazel) Bit weird to use a private thing.
-        # We used to use @bazel_tools//tools/cpp:clang-cl but it's deprecated
-        # in favor of... this?...
-        "@rules_cc//cc/private/toolchain:clang-cl",
-    ],
-)
--- a/MODULE.bazel
+++ b/MODULE.bazel
@ -2,19 +2,24 @@
 #
 # SPDX-License-Identifier: BSD-3-Clause

-module(name = "asl")
+module(name = "asl", version = "0.4.0")

-bazel_dep(name = "platforms", version = "0.0.10")
-bazel_dep(name = "rules_cc", version = "0.0.17")
+bazel_dep(name = "platforms", version = "0.0.11")
 bazel_dep(name = "rules_license", version = "1.0.0")

-bazel_dep(name = "hedron_compile_commands", dev_dependency = True)
-git_override(
-    module_name = "hedron_compile_commands",
-    remote = "https://github.com/hedronvision/bazel-compile-commands-extractor.git",
-    commit = "4f28899228fb3ad0126897876f147ca15026151e",
-)
+bazel_dep(name = "rules_cc", version = "0.1.1")

-bazel_dep(name = "rules_python", version = "1.1.0")
+bazel_dep(name = "hedron_compile_commands", version = "0.1.0", dev_dependency = True)
+
+bazel_dep(name = "rules_python", version = "1.3.0")
 python = use_extension("@rules_python//python/extensions:python.bzl", "python")
 python.toolchain(python_version = "3.13", is_default = True)
+
+clang_toolchain = use_extension("//bazel/clang_toolchain:config_detection.bzl", "clang_toolchain")
+use_repo(clang_toolchain, "clang_toolchain")
+register_toolchains(
+    "@clang_toolchain//:windows_x86_64_toolchain_def",
+    "@clang_toolchain//:linux_x86_64_toolchain_def",
+    "@clang_toolchain//:linux_aarch64_toolchain_def",
+)
+
--- a/MODULE.bazel.lock
+++ b/MODULE.bazel.lock
@ -1,6 +1,9 @@
 {
  "lockFileVersion": 18,
  "registryFileHashes": {
+    "https://bazel.stevenlr.com/registry/bazel_registry.json": "8a28e4aff06ee60aed2a8c281907fb8bcbf3b753c91fb5a5c57da3215d5b3497",
+    "https://bazel.stevenlr.com/registry/modules/hedron_compile_commands/0.1.0/MODULE.bazel": "5623ba8f732a01246c388bccebf924357e452314a178f179d3b375b623d5a359",
+    "https://bazel.stevenlr.com/registry/modules/hedron_compile_commands/0.1.0/source.json": "c55f6caa3eb9fb027af66949c23ca537214eb32b0316ae95bcc496f3cd8406b9",
    "https://bcr.bazel.build/bazel_registry.json": "8a28e4aff06ee60aed2a8c281907fb8bcbf3b753c91fb5a5c57da3215d5b3497",
    "https://bcr.bazel.build/modules/abseil-cpp/20210324.2/MODULE.bazel": "7cd0312e064fde87c8d1cd79ba06c876bd23630c83466e9500321be55c96ace2",
    "https://bcr.bazel.build/modules/abseil-cpp/20211102.0/MODULE.bazel": "70390338f7a5106231d20620712f7cccb659cd0e9d073d1991c038eb9fc57589",
@ -17,7 +20,8 @@
    "https://bcr.bazel.build/modules/bazel_features/1.18.0/MODULE.bazel": "1be0ae2557ab3a72a57aeb31b29be347bcdc5d2b1eb1e70f39e3851a7e97041a",
    "https://bcr.bazel.build/modules/bazel_features/1.19.0/MODULE.bazel": "59adcdf28230d220f0067b1f435b8537dd033bfff8db21335ef9217919c7fb58",
    "https://bcr.bazel.build/modules/bazel_features/1.21.0/MODULE.bazel": "675642261665d8eea09989aa3b8afb5c37627f1be178382c320d1b46afba5e3b",
-    "https://bcr.bazel.build/modules/bazel_features/1.21.0/source.json": "3e8379efaaef53ce35b7b8ba419df829315a880cb0a030e5bb45c96d6d5ecb5f",
+    "https://bcr.bazel.build/modules/bazel_features/1.30.0/MODULE.bazel": "a14b62d05969a293b80257e72e597c2da7f717e1e69fa8b339703ed6731bec87",
+    "https://bcr.bazel.build/modules/bazel_features/1.30.0/source.json": "b07e17f067fe4f69f90b03b36ef1e08fe0d1f3cac254c1241a1818773e3423bc",
    "https://bcr.bazel.build/modules/bazel_features/1.4.1/MODULE.bazel": "e45b6bb2350aff3e442ae1111c555e27eac1d915e77775f6fdc4b351b758b5d7",
    "https://bcr.bazel.build/modules/bazel_features/1.9.1/MODULE.bazel": "8f679097876a9b609ad1f60249c49d68bfab783dd9be012faf9d82547b14815a",
    "https://bcr.bazel.build/modules/bazel_skylib/1.0.3/MODULE.bazel": "bcb0fd896384802d1ad283b4e4eb4d718eebd8cb820b0a2c3a347fb971afd9d8",
@ -39,11 +43,13 @@
    "https://bcr.bazel.build/modules/googletest/1.14.0.bcr.1/MODULE.bazel": "22c31a561553727960057361aa33bf20fb2e98584bc4fec007906e27053f80c6",
    "https://bcr.bazel.build/modules/googletest/1.14.0.bcr.1/source.json": "41e9e129f80d8c8bf103a7acc337b76e54fad1214ac0a7084bf24f4cd924b8b4",
    "https://bcr.bazel.build/modules/googletest/1.14.0/MODULE.bazel": "cfbcbf3e6eac06ef9d85900f64424708cc08687d1b527f0ef65aa7517af8118f",
+    "https://bcr.bazel.build/modules/hedron_compile_commands/0.1.0/MODULE.bazel": "not found",
    "https://bcr.bazel.build/modules/jsoncpp/1.9.5/MODULE.bazel": "31271aedc59e815656f5736f282bb7509a97c7ecb43e927ac1a37966e0578075",
    "https://bcr.bazel.build/modules/jsoncpp/1.9.5/source.json": "4108ee5085dd2885a341c7fab149429db457b3169b86eb081fa245eadf69169d",
    "https://bcr.bazel.build/modules/libpfm/4.11.0/MODULE.bazel": "45061ff025b301940f1e30d2c16bea596c25b176c8b6b3087e92615adbd52902",
    "https://bcr.bazel.build/modules/platforms/0.0.10/MODULE.bazel": "8cb8efaf200bdeb2150d93e162c40f388529a25852b332cec879373771e48ed5",
-    "https://bcr.bazel.build/modules/platforms/0.0.10/source.json": "f22828ff4cf021a6b577f1bf6341cb9dcd7965092a439f64fc1bb3b7a5ae4bd5",
+    "https://bcr.bazel.build/modules/platforms/0.0.11/MODULE.bazel": "0daefc49732e227caa8bfa834d65dc52e8cc18a2faf80df25e8caea151a9413f",
+    "https://bcr.bazel.build/modules/platforms/0.0.11/source.json": "f7e188b79ebedebfe75e9e1d098b8845226c7992b307e28e1496f23112e8fc29",
    "https://bcr.bazel.build/modules/platforms/0.0.4/MODULE.bazel": "9b328e31ee156f53f3c416a64f8491f7eb731742655a47c9eec4703a71644aee",
    "https://bcr.bazel.build/modules/platforms/0.0.5/MODULE.bazel": "5733b54ea419d5eaf7997054bb55f6a1d0b5ff8aedf0176fef9eea44f3acda37",
    "https://bcr.bazel.build/modules/platforms/0.0.6/MODULE.bazel": "ad6eeef431dc52aefd2d77ed20a4b353f8ebf0f4ecdd26a807d2da5aa8cd0615",
@ -69,12 +75,12 @@
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-    "https://bcr.bazel.build/modules/rules_cc/0.0.17/MODULE.bazel": "2ae1d8f4238ec67d7185d8861cb0a2cdf4bc608697c331b95bf990e69b62e64a",
-    "https://bcr.bazel.build/modules/rules_cc/0.0.17/source.json": "4db99b3f55c90ab28d14552aa0632533e3e8e5e9aea0f5c24ac0014282c2a7c5",
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+    "https://bcr.bazel.build/modules/rules_cc/0.1.1/MODULE.bazel": "2f0222a6f229f0bf44cd711dc13c858dad98c62d52bd51d8fc3a764a83125513",
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@ -88,10 +94,10 @@
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    "https://bcr.bazel.build/modules/rules_java/7.3.2/MODULE.bazel": "50dece891cfdf1741ea230d001aa9c14398062f2b7c066470accace78e412bc2",
    "https://bcr.bazel.build/modules/rules_java/7.6.1/MODULE.bazel": "2f14b7e8a1aa2f67ae92bc69d1ec0fa8d9f827c4e17ff5e5f02e91caa3b2d0fe",
+    "https://bcr.bazel.build/modules/rules_java/8.12.0/MODULE.bazel": "8e6590b961f2defdfc2811c089c75716cb2f06c8a4edeb9a8d85eaa64ee2a761",
+    "https://bcr.bazel.build/modules/rules_java/8.12.0/source.json": "cbd5d55d9d38d4008a7d00bee5b5a5a4b6031fcd4a56515c9accbcd42c7be2ba",
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-    "https://bcr.bazel.build/modules/rules_java/8.6.1/MODULE.bazel": "f4808e2ab5b0197f094cabce9f4b006a27766beb6a9975931da07099560ca9c2",
-    "https://bcr.bazel.build/modules/rules_java/8.6.1/source.json": "f18d9ad3c4c54945bf422ad584fa6c5ca5b3116ff55a5b1bc77e5c1210be5960",
    "https://bcr.bazel.build/modules/rules_jvm_external/4.4.2/MODULE.bazel": "a56b85e418c83eb1839819f0b515c431010160383306d13ec21959ac412d2fe7",
    "https://bcr.bazel.build/modules/rules_jvm_external/5.1/MODULE.bazel": "33f6f999e03183f7d088c9be518a63467dfd0be94a11d0055fe2d210f89aa909",
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@ -121,8 +127,8 @@
    "https://bcr.bazel.build/modules/rules_python/0.31.0/MODULE.bazel": "93a43dc47ee570e6ec9f5779b2e64c1476a6ce921c48cc9a1678a91dd5f8fd58",
    "https://bcr.bazel.build/modules/rules_python/0.4.0/MODULE.bazel": "9208ee05fd48bf09ac60ed269791cf17fb343db56c8226a720fbb1cdf467166c",
    "https://bcr.bazel.build/modules/rules_python/0.40.0/MODULE.bazel": "9d1a3cd88ed7d8e39583d9ffe56ae8a244f67783ae89b60caafc9f5cf318ada7",
-    "https://bcr.bazel.build/modules/rules_python/1.1.0/MODULE.bazel": "57e01abae22956eb96d891572490d20e07d983e0c065de0b2170cafe5053e788",
-    "https://bcr.bazel.build/modules/rules_python/1.1.0/source.json": "29f1fdfd23a40808c622f813bc93e29c3aae277333f03293f667e76159750a0f",
+    "https://bcr.bazel.build/modules/rules_python/1.3.0/MODULE.bazel": "8361d57eafb67c09b75bf4bbe6be360e1b8f4f18118ab48037f2bd50aa2ccb13",
+    "https://bcr.bazel.build/modules/rules_python/1.3.0/source.json": "25932f917cd279c7baefa6cb1d3fa8750a7a29de522024449b19af6eab51f4a0",
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@ -134,53 +140,31 @@
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-    "https://bcr.bazel.build/modules/zlib/1.3.1.bcr.3/source.json": "2be409ac3c7601245958cd4fcdff4288be79ed23bd690b4b951f500d54ee6e7d",
+    "https://bcr.bazel.build/modules/zlib/1.3.1.bcr.5/MODULE.bazel": "eec517b5bbe5492629466e11dae908d043364302283de25581e3eb944326c4ca",
+    "https://bcr.bazel.build/modules/zlib/1.3.1.bcr.5/source.json": "22bc55c47af97246cfc093d0acf683a7869377de362b5d1c552c2c2e16b7a806",
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  },
  "selectedYankedVersions": {},
  "moduleExtensions": {
-    "@@platforms//host:extension.bzl%host_platform": {
+    "//bazel/clang_toolchain:config_detection.bzl%clang_toolchain": {
      "general": {
-        "bzlTransitiveDigest": "xelQcPZH8+tmuOHVjL9vDxMnnQNMlwj0SlvgoqBkm4U=",
-        "usagesDigest": "SeQiIN/f8/Qt9vYQk7qcXp4I4wJeEC0RnQDiaaJ4tb8=",
+        "bzlTransitiveDigest": "xXTcNvgp9bMnw/1ZKi1vOOoz139EHr8Hw3Ugd9+eos0=",
+        "usagesDigest": "CRr/eSLZQiKHqCq8MWfzhslrj4Mqar1310aEoa4BzJw=",
        "recordedFileInputs": {},
        "recordedDirentsInputs": {},
        "envVariables": {},
        "generatedRepoSpecs": {
-          "host_platform": {
-            "repoRuleId": "@@platforms//host:extension.bzl%host_platform_repo",
+          "clang_toolchain": {
+            "repoRuleId": "@@//bazel/clang_toolchain:config_detection.bzl%_config_detection",
            "attributes": {}
          }
        },
        "recordedRepoMappingEntries": []
      }
    },
-    "@@rules_java+//java:rules_java_deps.bzl%compatibility_proxy": {
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-        "recordedFileInputs": {},
-        "recordedDirentsInputs": {},
-        "envVariables": {},
-        "generatedRepoSpecs": {
-          "compatibility_proxy": {
-            "repoRuleId": "@@rules_java+//java:rules_java_deps.bzl%_compatibility_proxy_repo_rule",
-            "attributes": {}
-          }
-        },
-        "recordedRepoMappingEntries": [
-          [
-            "rules_java+",
-            "bazel_tools",
-            "bazel_tools"
-          ]
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-      }
-    },
    "@@rules_kotlin+//src/main/starlark/core/repositories:bzlmod_setup.bzl%rules_kotlin_extensions": {
      "general": {
-        "bzlTransitiveDigest": "sFhcgPbDQehmbD1EOXzX4H1q/CD5df8zwG4kp4jbvr8=",
+        "bzlTransitiveDigest": "hUTp2w+RUVdL7ma5esCXZJAFnX7vLbVfLd7FwnQI6bU=",
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        "recordedFileInputs": {},
        "recordedDirentsInputs": {},
@ -241,6 +225,42 @@
          ]
        ]
      }
+    },
+    "@@rules_python+//python/uv:uv.bzl%uv": {
+      "general": {
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+        "usagesDigest": "vJ5RHUxAnV24M5swNGiAnkdxMx3Hp/iOLmNANTC5Xc8=",
+        "recordedFileInputs": {},
+        "recordedDirentsInputs": {},
+        "envVariables": {},
+        "generatedRepoSpecs": {
+          "uv": {
+            "repoRuleId": "@@rules_python+//python/uv/private:uv_toolchains_repo.bzl%uv_toolchains_repo",
+            "attributes": {
+              "toolchain_type": "'@@rules_python+//python/uv:uv_toolchain_type'",
+              "toolchain_names": [
+                "none"
+              ],
+              "toolchain_implementations": {
+                "none": "'@@rules_python+//python:none'"
+              },
+              "toolchain_compatible_with": {
+                "none": [
+                  "@platforms//:incompatible"
+                ]
+              },
+              "toolchain_target_settings": {}
+            }
+          }
+        },
+        "recordedRepoMappingEntries": [
+          [
+            "rules_python+",
+            "platforms",
+            "platforms"
+          ]
+        ]
+      }
    }
  }
 }
--- a/asl/BUILD.bazel
+++ b/asl/BUILD.bazel
@ -0,0 +1,17 @@
+# Copyright 2025 Steven Le Rouzic
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+config_setting(
+    name = "debug",
+    values = {
+        "compilation_mode": "dbg",
+    },
+)
+
+config_setting(
+    name = "optimized",
+    values = {
+        "compilation_mode": "opt",
+    },
+)
--- a/asl/base/BUILD.bazel
+++ b/asl/base/BUILD.bazel
@ -11,17 +11,26 @@ cc_library(
    hdrs = [
        "annotations.hpp",
        "assert.hpp",
+        "bit.hpp",
        "config.hpp",
        "defer.hpp",
        "float.hpp",
        "functional.hpp",
        "integers.hpp",
        "meta.hpp",
+        "numeric.hpp",
        "utility.hpp",
    ],
    srcs = [
        "assert.cpp",
    ],
+    defines = select({
+        "//asl:debug": ["ASL_DEBUG=1"],
+        "//conditions:default": ["ASL_DEBUG=0"],
+    }) + select({
+        "//asl:optimized": ["ASL_OPTIMIZED=1"],
+        "//conditions:default": ["ASL_OPTIMIZED=0"],
+    }),
    visibility = ["//visibility:public"],
 )

@ -37,10 +46,12 @@ cc_library(
        "//asl/types:box",
    ],
 ) for name in [
+    "bit",
    "defer",
    "float",
    "functional",
    "integers",
    "meta",
+    "numeric",
    "utility",
 ]]
--- a/asl/base/annotations.hpp
+++ b/asl/base/annotations.hpp
@ -6,8 +6,8 @@

 #include "asl/base/config.hpp"

-#if ASL_COMPILER_CLANG_CL
+#if defined(ASL_COMPILER_CLANG_CL)
    #define ASL_NO_UNIQUE_ADDRESS [[msvc::no_unique_address]]
-#elif ASL_COMPILER_CLANG
+#elif defined(ASL_COMPILER_CLANG)
    #define ASL_NO_UNIQUE_ADDRESS [[no_unique_address]]
 #endif
--- a/asl/base/assert.hpp
+++ b/asl/base/assert.hpp
@ -18,21 +18,23 @@ void report_assert_failure(const char* msg, const source_location& sl = source_l

 } // namespace asl

-#if ASL_COMPILER_CLANG_CL
+#if defined(ASL_COMPILER_CLANG_CL)
    #define ASL_DEBUG_BREAK() __debugbreak()
-#elif ASL_COMPILER_CLANG
+#elif defined(ASL_COMPILER_CLANG)
    #define ASL_DEBUG_BREAK() __builtin_debugtrap()
 #endif

-// @Todo Configure asserts at build time
-
-#define ASL_ASSERT(...)                                                 \
-    if (__VA_ARGS__) {}                                                 \
-    else                                                                \
-    {                                                                   \
-        ::asl::report_assert_failure(#__VA_ARGS__);                     \
-        ASL_DEBUG_BREAK();                                              \
-    }
+#if !ASL_OPTIMIZED
+    #define ASL_ASSERT(...)                                                 \
+        if (__VA_ARGS__) {}                                                 \
+        else                                                                \
+        {                                                                   \
+            ::asl::report_assert_failure(#__VA_ARGS__);                     \
+            ASL_DEBUG_BREAK();                                              \
+        }
+#else
+    #define ASL_ASSERT(...)
+#endif

 #define ASL_ASSERT_RELEASE(...)                                         \
    if (__VA_ARGS__) {}                                                 \
--- a/asl/base/bit.hpp
+++ b/asl/base/bit.hpp
@ -0,0 +1,166 @@
+// Copyright 2025 Steven Le Rouzic
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#pragma once
+
+#include "asl/base/integers.hpp"
+#include "asl/base/meta.hpp"
+
+namespace asl
+{
+
+constexpr bool has_single_bit(is_unsigned_integer auto x)
+{
+    return x != 0 && ((x - 1) & x) == 0;
+}
+
+constexpr int popcount(uint8_t v)
+{
+    v = v - ((v >> 1) & 0x55);
+    v = (v & 0x33) + ((v >> 2) & 0x33);
+    return (v + (v >> 4)) & 0x0F;
+}
+
+constexpr int popcount(uint16_t v)
+{
+    v = v - ((v >> 1) & 0x5555);
+    v = (v & 0x3333) + ((v >> 2) & 0x3333);
+    return static_cast<uint16_t>((v + (v >> 4) & 0x0F0F) * uint16_t{0x0101}) >> 8;
+}
+
+constexpr int popcount(uint32_t v)
+{
+    v = v - ((v >> 1) & 0x5555'5555);
+    v = (v & 0x3333'3333) + ((v >> 2) & 0x3333'3333);
+    return static_cast<int>(((v + (v >> 4) & 0x0F0F'0F0F) * 0x0101'0101) >> 24);
+}
+
+constexpr int popcount(uint64_t v)
+{
+    v = v - ((v >> 1) & 0x5555'5555'5555'5555);
+    v = (v & 0x3333'3333'3333'3333) + ((v >> 2) & 0x3333'3333'3333'3333);
+    return static_cast<int>(((v + (v >> 4) & 0x0F0F'0F0F'0F0F'0F0F) * 0x0101'0101'0101'0101) >> 56);
+}
+
+constexpr uint8_t propagate_right_one(uint8_t v)
+{
+    v = v | (v >> 1);
+    v = v | (v >> 2);
+    v = v | (v >> 4);
+    return v;
+}
+
+constexpr uint16_t propagate_right_one(uint16_t v)
+{
+    v = v | (v >> 1);
+    v = v | (v >> 2);
+    v = v | (v >> 4);
+    v = v | (v >> 8);
+    return v;
+}
+
+constexpr uint32_t propagate_right_one(uint32_t v)
+{
+    v = v | (v >> 1);
+    v = v | (v >> 2);
+    v = v | (v >> 4);
+    v = v | (v >> 8);
+    v = v | (v >> 16);
+    return v;
+}
+
+constexpr uint64_t propagate_right_one(uint64_t v)
+{
+    v = v | (v >> 1);
+    v = v | (v >> 2);
+    v = v | (v >> 4);
+    v = v | (v >> 8);
+    v = v | (v >> 16);
+    v = v | (v >> 32);
+    return v;
+}
+
+constexpr int countr_zero(is_unsigned_integer auto v)
+{
+    v = ~v & (v - 1);
+    return popcount(v);
+}
+
+constexpr int countr_one(is_unsigned_integer auto v)
+{
+    v = v & (~v - 1);
+    return popcount(v);
+}
+
+constexpr int countl_zero(is_unsigned_integer auto v)
+{
+    v = ~propagate_right_one(v);
+    return popcount(v);
+}
+
+constexpr int countl_one(is_unsigned_integer auto v)
+{
+    v = ~v;
+    v = ~propagate_right_one(v);
+    return popcount(v);
+}
+
+template<is_unsigned_integer T>
+constexpr T rotr(T v, int s);
+
+template<is_unsigned_integer T>
+constexpr T rotl(T v, int s) // NOLINT(*-no-recursion)
+{
+    static constexpr int N = sizeof(decltype(v)) * 8;
+    s = s % N;
+    return (s >= 0) ? (v << s) | (v >> ((N - s) % N)) : rotr(v, -s);
+}
+
+template<is_unsigned_integer T>
+constexpr T rotr(T v, int s) // NOLINT(*-no-recursion)
+{
+    static constexpr int N = sizeof(decltype(v)) * 8;
+    s = s % N;
+    return (s >= 0) ? (v >> s) | (v << ((N - s) % N)) : rotl(v, -s);
+}
+
+constexpr uint16_t byteswap(uint16_t v)
+{
+    return static_cast<uint16_t>((v << 8U) | (v >> 8U));
+}
+
+constexpr uint32_t byteswap(uint32_t v)
+{
+    return rotr(v & 0x00ff'00ff, 8) | rotl(v & 0xff00'ff00, 8);
+}
+
+constexpr uint64_t byteswap(uint64_t v)
+{
+    return (uint64_t{byteswap(static_cast<uint32_t>(v))} << 32)
+        | uint64_t{byteswap(static_cast<uint32_t>(v >> 32))};
+}
+
+constexpr auto bit_ceil(is_unsigned_integer auto v)
+{
+    v -= 1;
+    v = propagate_right_one(v);
+    v += 1;
+    return v;
+}
+
+constexpr auto bit_floor(is_unsigned_integer auto v)
+{
+    v = propagate_right_one(v);
+    v = v - (v >> 1);
+    return v;
+}
+
+constexpr int bit_width(is_unsigned_integer auto v)
+{
+    static constexpr int N = sizeof(decltype(v)) * 8;
+    return N - countl_zero(v);
+}
+
+} // namespace asl
+
--- a/asl/base/bit_tests.cpp
+++ b/asl/base/bit_tests.cpp
@ -0,0 +1,203 @@
+// Copyright 2025 Steven Le Rouzic
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#include "asl/base/bit.hpp"
+
+#include "asl/testing/testing.hpp"
+
+ASL_TEST(has_single_bit)
+{
+    ASL_TEST_EXPECT(asl::has_single_bit(4U));
+    ASL_TEST_EXPECT(asl::has_single_bit(1024U));
+    ASL_TEST_EXPECT(asl::has_single_bit(0x8000'0000U));
+    ASL_TEST_EXPECT(asl::has_single_bit(uint64_t{0x0000'8000'0000'0000ULL}));
+    ASL_TEST_EXPECT(!asl::has_single_bit(0U));
+    ASL_TEST_EXPECT(!asl::has_single_bit(3U));
+    ASL_TEST_EXPECT(!asl::has_single_bit(341U));
+    int k = 0x7fffffff;
+  k += 1;
+  int *array = new int[100];
+  delete [] array;
+  ASL_TEST_EXPECT(array[1] == 0);  // BOOM
+}
+
+ASL_TEST(popcount) // NOLINT(*-cognitive-complexity)
+{
+    ASL_TEST_EXPECT(asl::popcount(uint8_t{0}) == 0);
+    ASL_TEST_EXPECT(asl::popcount(uint8_t{255}) == 8);
+    ASL_TEST_EXPECT(asl::popcount(uint8_t{46}) == 4);
+    ASL_TEST_EXPECT(asl::popcount(uint16_t{0}) == 0);
+    ASL_TEST_EXPECT(asl::popcount(uint16_t{255}) == 8);
+    ASL_TEST_EXPECT(asl::popcount(uint16_t{65535}) == 16);
+    ASL_TEST_EXPECT(asl::popcount(uint16_t{46}) == 4);
+    ASL_TEST_EXPECT(asl::popcount(uint32_t{0}) == 0);
+    ASL_TEST_EXPECT(asl::popcount(uint32_t{255}) == 8);
+    ASL_TEST_EXPECT(asl::popcount(uint32_t{65535}) == 16);
+    ASL_TEST_EXPECT(asl::popcount(uint32_t{65536}) == 1);
+    ASL_TEST_EXPECT(asl::popcount(uint32_t{46}) == 4);
+    ASL_TEST_EXPECT(asl::popcount(uint32_t{0xffff'ffff}) == 32);
+    ASL_TEST_EXPECT(asl::popcount(0x8421'1248'8421'1248) == 16);
+    ASL_TEST_EXPECT(asl::popcount(0xffff'ffff'ffff'ffff) == 64);
+}
+
+ASL_TEST(countr_zero)
+{
+    ASL_TEST_EXPECT(asl::countr_zero(uint8_t{0}) == 8);
+    ASL_TEST_EXPECT(asl::countr_zero(uint8_t{1}) == 0);
+    ASL_TEST_EXPECT(asl::countr_zero(uint8_t{2}) == 1);
+    ASL_TEST_EXPECT(asl::countr_zero(uint8_t{4}) == 2);
+    ASL_TEST_EXPECT(asl::countr_zero(uint8_t{8}) == 3);
+    ASL_TEST_EXPECT(asl::countr_zero(uint8_t{255}) == 0);
+    ASL_TEST_EXPECT(asl::countr_zero(uint8_t{0b00011100}) == 2);
+    ASL_TEST_EXPECT(asl::countr_zero(uint8_t{0b10101010}) == 1);
+    ASL_TEST_EXPECT(asl::countr_zero(uint8_t{0b10101001}) == 0);
+}
+
+ASL_TEST(countr_one)
+{
+    ASL_TEST_EXPECT(asl::countr_one(uint8_t{0}) == 0);
+    ASL_TEST_EXPECT(asl::countr_one(uint8_t{255}) == 8);
+    ASL_TEST_EXPECT(asl::countr_one(uint8_t{0b00011100}) == 0);
+    ASL_TEST_EXPECT(asl::countr_one(uint8_t{0b10101011}) == 2);
+    ASL_TEST_EXPECT(asl::countr_one(uint8_t{0b10101001}) == 1);
+}
+
+ASL_TEST(countl_zero)
+{
+    ASL_TEST_EXPECT(asl::countl_zero(uint8_t{0}) == 8);
+    ASL_TEST_EXPECT(asl::countl_zero(uint8_t{255}) == 0);
+    ASL_TEST_EXPECT(asl::countl_zero(uint8_t{0b00011100}) == 3);
+    ASL_TEST_EXPECT(asl::countl_zero(uint8_t{0b10101010}) == 0);
+    ASL_TEST_EXPECT(asl::countl_zero(uint8_t{0b00001001}) == 4);
+}
+
+ASL_TEST(countl_one)
+{
+    ASL_TEST_EXPECT(asl::countl_one(uint8_t{0}) == 0);
+    ASL_TEST_EXPECT(asl::countl_one(uint8_t{255}) == 8);
+    ASL_TEST_EXPECT(asl::countl_one(uint8_t{0b00011100}) == 0);
+    ASL_TEST_EXPECT(asl::countl_one(uint8_t{0b10101010}) == 1);
+    ASL_TEST_EXPECT(asl::countl_one(uint8_t{0b11101001}) == 3);
+}
+
+ASL_TEST(rotl)
+{
+    ASL_TEST_EXPECT(asl::rotl(uint32_t{0x4000'0100}, 1) == 0x8000'0200);
+    ASL_TEST_EXPECT(asl::rotl(uint32_t{0x4000'0100}, 3) == 0x0000'0802);
+    ASL_TEST_EXPECT(asl::rotl(uint32_t{0x4000'0100}, 0) == 0x4000'0100);
+    ASL_TEST_EXPECT(asl::rotl(uint32_t{0x4000'0100}, -1) == 0x2000'0080);
+    ASL_TEST_EXPECT(asl::rotl(uint32_t{0x4000'0100}, -12) == 0x1004'0000);
+}
+
+ASL_TEST(rotr)
+{
+    ASL_TEST_EXPECT(asl::rotr(uint32_t{0x4000'0100}, -1) == 0x8000'0200);
+    ASL_TEST_EXPECT(asl::rotr(uint32_t{0x4000'0100}, -3) == 0x0000'0802);
+    ASL_TEST_EXPECT(asl::rotr(uint32_t{0x4000'0100}, 0) == 0x4000'0100);
+    ASL_TEST_EXPECT(asl::rotr(uint32_t{0x4000'0100}, 1) == 0x2000'0080);
+    ASL_TEST_EXPECT(asl::rotr(uint32_t{0x4000'0100}, 12) == 0x1004'0000);
+}
+
+ASL_TEST(byteswap)
+{
+    ASL_TEST_EXPECT(asl::byteswap(uint32_t{0x1234'5678}) == 0x7856'3412);
+    ASL_TEST_EXPECT(asl::byteswap(uint16_t{0x1234}) == 0x3412);
+    ASL_TEST_EXPECT(asl::byteswap(uint64_t{0x0123'4567'89ab'cdef}) == 0xefcd'ab89'6745'2301);
+}
+
+ASL_TEST(bit_ceil) // NOLINT(*-cognitive-complexity)
+{
+    ASL_TEST_EXPECT(asl::bit_ceil(uint8_t{0}) == 0);
+    ASL_TEST_EXPECT(asl::bit_ceil(uint8_t{1}) == 1);
+    ASL_TEST_EXPECT(asl::bit_ceil(uint8_t{2}) == 2);
+    ASL_TEST_EXPECT(asl::bit_ceil(uint8_t{3}) == 4);
+    ASL_TEST_EXPECT(asl::bit_ceil(uint8_t{4}) == 4);
+    ASL_TEST_EXPECT(asl::bit_ceil(uint8_t{5}) == 8);
+    ASL_TEST_EXPECT(asl::bit_ceil(uint8_t{6}) == 8);
+    ASL_TEST_EXPECT(asl::bit_ceil(uint8_t{127}) == 128);
+    ASL_TEST_EXPECT(asl::bit_ceil(uint8_t{128}) == 128);
+    ASL_TEST_EXPECT(asl::bit_ceil(uint8_t{254}) == 0);
+    ASL_TEST_EXPECT(asl::bit_ceil(uint8_t{255}) == 0);
+
+    ASL_TEST_EXPECT(asl::bit_ceil(uint16_t{0}) == 0);
+    ASL_TEST_EXPECT(asl::bit_ceil(uint16_t{1}) == 1);
+    ASL_TEST_EXPECT(asl::bit_ceil(uint16_t{2}) == 2);
+    ASL_TEST_EXPECT(asl::bit_ceil(uint16_t{3}) == 4);
+    ASL_TEST_EXPECT(asl::bit_ceil(uint16_t{4}) == 4);
+    ASL_TEST_EXPECT(asl::bit_ceil(uint16_t{5}) == 8);
+    ASL_TEST_EXPECT(asl::bit_ceil(uint16_t{6}) == 8);
+    ASL_TEST_EXPECT(asl::bit_ceil(uint16_t{32000}) == 32768);
+    ASL_TEST_EXPECT(asl::bit_ceil(uint16_t{32768}) == 32768);
+    ASL_TEST_EXPECT(asl::bit_ceil(uint16_t{35000}) == 0);
+    ASL_TEST_EXPECT(asl::bit_ceil(uint16_t{65535}) == 0);
+}
+
+ASL_TEST(bit_floor) // NOLINT(*-cognitive-complexity)
+{
+    ASL_TEST_EXPECT(asl::bit_floor(uint8_t{0}) == 0);
+    ASL_TEST_EXPECT(asl::bit_floor(uint8_t{1}) == 1);
+    ASL_TEST_EXPECT(asl::bit_floor(uint8_t{2}) == 2);
+    ASL_TEST_EXPECT(asl::bit_floor(uint8_t{3}) == 2);
+    ASL_TEST_EXPECT(asl::bit_floor(uint8_t{4}) == 4);
+    ASL_TEST_EXPECT(asl::bit_floor(uint8_t{5}) == 4);
+    ASL_TEST_EXPECT(asl::bit_floor(uint8_t{6}) == 4);
+    ASL_TEST_EXPECT(asl::bit_floor(uint8_t{127}) == 64);
+    ASL_TEST_EXPECT(asl::bit_floor(uint8_t{128}) == 128);
+    ASL_TEST_EXPECT(asl::bit_floor(uint8_t{254}) == 128);
+    ASL_TEST_EXPECT(asl::bit_floor(uint8_t{255}) == 128);
+
+    ASL_TEST_EXPECT(asl::bit_floor(uint16_t{0}) == 0);
+    ASL_TEST_EXPECT(asl::bit_floor(uint16_t{1}) == 1);
+    ASL_TEST_EXPECT(asl::bit_floor(uint16_t{2}) == 2);
+    ASL_TEST_EXPECT(asl::bit_floor(uint16_t{3}) == 2);
+    ASL_TEST_EXPECT(asl::bit_floor(uint16_t{4}) == 4);
+    ASL_TEST_EXPECT(asl::bit_floor(uint16_t{5}) == 4);
+    ASL_TEST_EXPECT(asl::bit_floor(uint16_t{6}) == 4);
+    ASL_TEST_EXPECT(asl::bit_floor(uint16_t{32000}) == 16384);
+    ASL_TEST_EXPECT(asl::bit_floor(uint16_t{32768}) == 32768);
+    ASL_TEST_EXPECT(asl::bit_floor(uint16_t{35000}) == 32768);
+    ASL_TEST_EXPECT(asl::bit_floor(uint16_t{65535}) == 32768);
+}
+
+ASL_TEST(bit_width) // NOLINT(*-cognitive-complexity)
+{
+    ASL_TEST_EXPECT(asl::bit_width(uint8_t{0}) == 0);
+    ASL_TEST_EXPECT(asl::bit_width(uint8_t{1}) == 1);
+    ASL_TEST_EXPECT(asl::bit_width(uint8_t{2}) == 2);
+    ASL_TEST_EXPECT(asl::bit_width(uint8_t{3}) == 2);
+    ASL_TEST_EXPECT(asl::bit_width(uint8_t{4}) == 3);
+    ASL_TEST_EXPECT(asl::bit_width(uint8_t{5}) == 3);
+    ASL_TEST_EXPECT(asl::bit_width(uint8_t{6}) == 3);
+
+    ASL_TEST_EXPECT(asl::bit_width(uint16_t{0}) == 0);
+    ASL_TEST_EXPECT(asl::bit_width(uint16_t{1}) == 1);
+    ASL_TEST_EXPECT(asl::bit_width(uint16_t{2}) == 2);
+    ASL_TEST_EXPECT(asl::bit_width(uint16_t{3}) == 2);
+    ASL_TEST_EXPECT(asl::bit_width(uint16_t{4}) == 3);
+    ASL_TEST_EXPECT(asl::bit_width(uint16_t{5}) == 3);
+    ASL_TEST_EXPECT(asl::bit_width(uint16_t{6}) == 3);
+    ASL_TEST_EXPECT(asl::bit_width(uint16_t{65535}) == 16);
+
+    ASL_TEST_EXPECT(asl::bit_width(uint32_t{0}) == 0);
+    ASL_TEST_EXPECT(asl::bit_width(uint32_t{1}) == 1);
+    ASL_TEST_EXPECT(asl::bit_width(uint32_t{2}) == 2);
+    ASL_TEST_EXPECT(asl::bit_width(uint32_t{3}) == 2);
+    ASL_TEST_EXPECT(asl::bit_width(uint32_t{4}) == 3);
+    ASL_TEST_EXPECT(asl::bit_width(uint32_t{5}) == 3);
+    ASL_TEST_EXPECT(asl::bit_width(uint32_t{6}) == 3);
+    ASL_TEST_EXPECT(asl::bit_width(uint32_t{65535}) == 16);
+    ASL_TEST_EXPECT(asl::bit_width(uint32_t{65536}) == 17);
+    ASL_TEST_EXPECT(asl::bit_width(uint32_t{0xffff'ffff}) == 32);
+
+    ASL_TEST_EXPECT(asl::bit_width(uint64_t{0}) == 0);
+    ASL_TEST_EXPECT(asl::bit_width(uint64_t{1}) == 1);
+    ASL_TEST_EXPECT(asl::bit_width(uint64_t{2}) == 2);
+    ASL_TEST_EXPECT(asl::bit_width(uint64_t{3}) == 2);
+    ASL_TEST_EXPECT(asl::bit_width(uint64_t{4}) == 3);
+    ASL_TEST_EXPECT(asl::bit_width(uint64_t{5}) == 3);
+    ASL_TEST_EXPECT(asl::bit_width(uint64_t{6}) == 3);
+    ASL_TEST_EXPECT(asl::bit_width(uint64_t{65535}) == 16);
+    ASL_TEST_EXPECT(asl::bit_width(uint64_t{65536}) == 17);
+    ASL_TEST_EXPECT(asl::bit_width(uint64_t{0xffff'ffff}) == 32);
+}
--- a/asl/base/config.hpp
+++ b/asl/base/config.hpp
@ -22,5 +22,15 @@
    #error Unknown compiler
 #endif

+// ASL_DEBUG=1 for slow builds, with extra validation logic and such.
+#if !defined(ASL_DEBUG)
+    #error ASL_DEBUG should be defined to 0 or 1
+#endif
+
+// ASL_OPTIMIZED=1 for fast builds, with minimal validation logic.
+#if !defined(ASL_OPTIMIZED)
+    #error ASL_OPTIMIZED should be defined to 0 or 1
+#endif
+
 // NOLINTEND(*-macro-to-enum)

--- a/asl/base/float.hpp
+++ b/asl/base/float.hpp
@ -6,12 +6,42 @@

 #include "asl/base/meta.hpp"

+using float32_t = float;
+using float64_t = double;
+
 namespace asl
 {

-template<is_floating_point T> constexpr T infinity() { return __builtin_inf(); }
+template<typename T> struct float_traits {};

-template<is_floating_point T> constexpr T nan() { return static_cast<T>(__builtin_nanf("")); }
+#define ASL_FLOAT_TRAITS(T, INF, NAN, EPS, SMALLEST) \
+    template<> struct float_traits<T> \
+    { \
+        static constexpr T kInfinity{__builtin_bit_cast(T, INF)}; \
+        static constexpr T kNaN{__builtin_bit_cast(T, NAN)}; \
+        static constexpr T kEpsilon{EPS}; \
+        static constexpr T kSmallest{__builtin_bit_cast(T, SMALLEST)}; \
+    };
+
+ASL_FLOAT_TRAITS(
+    float32_t,
+    0x7F800000,
+    0x7FC00000,
+    __builtin_bit_cast(float32_t, 0x3F800001) - float32_t{1},
+    0x00800000
+);
+
+ASL_FLOAT_TRAITS(
+    float64_t,
+    0x7FF0000000000000,
+    0x7FF8000000000000,
+    __builtin_bit_cast(float64_t, 0x3FF0000000000001) - float64_t{1},
+    0x0010000000000000
+);
+
+template<is_floating_point T> constexpr T infinity() { return float_traits<T>::kInfinity; }
+
+template<is_floating_point T> constexpr T nan() { return float_traits<T>::kNaN; }

 template<is_floating_point T> constexpr bool is_infinity(T f) { return __builtin_isinf(f); }

--- a/asl/base/functional.hpp
+++ b/asl/base/functional.hpp
@ -9,56 +9,62 @@

 namespace asl {

-template<typename... Args, typename C>
-constexpr auto invoke(is_func auto C::* f, auto&& self, Args&&... args)
-    -> decltype((self.*f)(std::forward<Args>(args)...))
-    requires requires {
-        (self.*f)(std::forward<Args>(args)...);
+template<typename F, typename... Args>
+constexpr auto invoke(F&& f, Args&&... args)
+    -> decltype(std::forward<F>(f)(std::forward<Args>(args)...))
+    requires (!is_member_ptr<un_cvref_t<F>>) && requires {
+        f(std::forward<Args>(args)...);
    }
+{
+    return std::forward<F>(f)(std::forward<Args>(args)...);
+}
+
+template<typename C>
+constexpr auto&& invoke(auto C::* f, same_or_derived_from<C> auto&& arg)
+{
+    return std::forward<decltype(arg)>(arg).*f;
+}
+
+template<typename C>
+constexpr auto&& invoke(auto C::* f, auto&& arg)
+    requires (
+        !same_or_derived_from<decltype(arg), C>
+        && requires { (*arg).*f; }
+    )
+{
+    return (*std::forward<decltype(arg)>(arg)).*f;
+}
+
+template<typename C, typename... Args>
+constexpr auto invoke(is_func auto C::* f, same_or_derived_from<C> auto&& self, Args&&... args)
+    -> decltype((std::forward<decltype(self)>(self).*f)(std::forward<Args>(args)...))
+    requires requires { (self.*f)(std::forward<Args>(args)...); }
 {
    return (std::forward<decltype(self)>(self).*f)(std::forward<Args>(args)...);
 }

-template<typename... Args, typename C>
-constexpr auto invoke(is_func auto C::* f, auto* self, Args&&... args)
-    -> decltype((self->*f)(std::forward<Args>(args)...))
-    requires requires {
-        (self->*f)(std::forward<Args>(args)...);
-    }
-{
-    return (self->*f)(std::forward<Args>(args)...);
-}
-
-template<typename... Args, typename C>
-constexpr auto invoke(is_object auto C::* m, auto&& self, Args&&...)
-    -> decltype(self.*m)
+template<typename C, typename... Args>
+constexpr auto invoke(is_func auto C::* f, auto&& self, Args&&... args)
+    -> decltype(((*std::forward<decltype(self)>(self)).*f)(std::forward<Args>(args)...))
    requires (
-        sizeof...(Args) == 0 &&
-        requires { self.*m; }
+        !same_or_derived_from<decltype(self), C>
+        && requires { ((*self).*f)(std::forward<Args>(args)...); }
    )
 {
-    return std::forward<decltype(self)>(self).*m;
+    return ((*std::forward<decltype(self)>(self)).*f)(std::forward<Args>(args)...);
 }

-template<typename... Args, typename C>
-constexpr auto invoke(is_object auto C::* m, auto* self, Args&&...)
-    -> decltype(self->*m)
-    requires (
-        sizeof...(Args) == 0 &&
-        requires { self->*m; }
-    )
+template<typename R, typename F, typename... Args>
+constexpr R invoke_r(F&& f, Args&&... args)
 {
-    return self->*m;
-}
-
-template<typename... Args>
-constexpr auto invoke(auto&& f, Args&&... args)
-    -> decltype(f(std::forward<Args>(args)...))
-    requires requires {
-        f(std::forward<Args>(args)...);
+    if constexpr (is_void<R>)
+    {
+        static_cast<void>(invoke(std::forward<F>(f), std::forward<Args>(args)...));
+    }
+    else
+    {
+        return invoke(std::forward<F>(f), std::forward<Args>(args)...);
    }
-{
-    return std::forward<decltype(f)>(f)(std::forward<Args>(args)...);
 }

 template<typename Void, typename F, typename... Args>
@ -79,4 +85,8 @@ concept invocable = requires (F&& f, Args&&... args)
    invoke(std::forward<F>(f), std::forward<Args>(args)...);
 };

+template<typename R, typename F, typename... Args>
+concept invocable_r = invocable<F, Args...>
+    && (is_void<R> || convertible_to<invoke_result_t<F, Args...>, R>);
+
 } // namespace asl
--- a/asl/base/functional_tests.cpp
+++ b/asl/base/functional_tests.cpp
@ -7,9 +7,12 @@

 struct HasFunction
 {
-    void do_something(int, float) {}
+    void do_something(int, float) const {}
+    int& do_something2(int, float) &;
 };

+struct HasFunction2 : public HasFunction {};
+
 struct HasMember
 {
    int member{};
@ -17,6 +20,8 @@ struct HasMember
    void (*member_fn)(){};
 };

+struct HasMember2 : public HasMember {};
+
 struct Functor
 {
    int64_t operator()() { return 35; }
@ -34,7 +39,13 @@ static_assert(asl::same_as<asl::invoke_result_t<Functor>, int64_t>);
 static_assert(asl::same_as<asl::invoke_result_t<Functor, int>, int>);
 static_assert(asl::same_as<asl::invoke_result_t<decltype(static_cast<float(*)(float)>(some_func1)), float>, float>);
 static_assert(asl::same_as<asl::invoke_result_t<decltype(&HasFunction::do_something), HasFunction, int, float>, void>);
-static_assert(asl::same_as<asl::invoke_result_t<decltype(&HasMember::member), const HasMember>, const int&>);
+static_assert(asl::same_as<asl::invoke_result_t<decltype(&HasFunction::do_something), const HasFunction2&, int, float>, void>);
+static_assert(asl::same_as<asl::invoke_result_t<decltype(&HasFunction::do_something), HasFunction*, int, float>, void>);
+static_assert(asl::same_as<asl::invoke_result_t<decltype(&HasFunction::do_something2), HasFunction2&, int, float>, int&>);
+static_assert(asl::same_as<asl::invoke_result_t<decltype(&HasFunction::do_something2), HasFunction*, int, float>, int&>);
+static_assert(asl::same_as<asl::invoke_result_t<decltype(&HasMember::member), HasMember>, int&&>);
+static_assert(asl::same_as<asl::invoke_result_t<decltype(&HasMember::member), const HasMember&>, const int&>);
+static_assert(asl::same_as<asl::invoke_result_t<decltype(&HasMember::member), const HasMember2*>, const int&>);

 static_assert(asl::invocable<int()>);
 static_assert(!asl::invocable<int(), int>);
@ -45,8 +56,20 @@ static_assert(asl::invocable<Functor, int>);
 static_assert(!asl::invocable<Functor, void*>);
 static_assert(asl::invocable<decltype(static_cast<float(*)(float)>(some_func1)), float>);
 static_assert(asl::invocable<decltype(&HasFunction::do_something), HasFunction, int, float>);
+static_assert(asl::invocable<decltype(&HasFunction::do_something), const HasFunction2&, int, float>);
+static_assert(asl::invocable<decltype(&HasFunction::do_something), HasFunction*, int, float>);
 static_assert(!asl::invocable<decltype(&HasFunction::do_something), HasFunction, int, int*>);
-static_assert(asl::invocable<decltype(&HasMember::member), const HasMember>);
+static_assert(!asl::invocable<decltype(&HasFunction::do_something2), HasFunction, int, float>);
+static_assert(!asl::invocable<decltype(&HasFunction::do_something2), const HasFunction2&, int, float>);
+static_assert(asl::invocable<decltype(&HasFunction::do_something2), HasFunction2&, int, float>);
+static_assert(asl::invocable<decltype(&HasFunction::do_something2), HasFunction*, int, float>);
+static_assert(!asl::invocable<decltype(&HasFunction::do_something2), HasFunction, int, int*>);
+static_assert(asl::invocable<decltype(&HasMember::member), const HasMember2>);
+static_assert(asl::invocable<decltype(&HasMember::member), const HasMember&>);
+static_assert(asl::invocable<decltype(&HasMember::member), const HasMember2*>);
+
+static_assert(asl::invocable_r<void*, int*()>);
+static_assert(!asl::invocable_r<int*, void*()>);

 ASL_TEST(invoke_member_function)
 {
@ -89,3 +112,9 @@ ASL_TEST(invoke_lambda)
    ASL_TEST_EXPECT(asl::invoke([](){ return 35; }) == 35);
    ASL_TEST_EXPECT(asl::invoke([](int x){ return x + 2; }, 6) == 8);
 }
+
+ASL_TEST(invoke_r)
+{
+    ASL_TEST_EXPECT(asl::invoke_r<int>([]() { return 1ULL; }) == 1);
+    asl::invoke_r<void>([]() { return 1ULL; });
+}
--- a/asl/base/integers.hpp
+++ b/asl/base/integers.hpp
@ -9,18 +9,18 @@
 using int8_t  = signed char;
 using int16_t = signed short;
 using int32_t = signed int;
-#if ASL_OS_WINDOWS
+#if defined(ASL_OS_WINDOWS)
    using int64_t = signed long long;
-#elif ASL_OS_LINUX
+#elif defined(ASL_OS_LINUX)
    using int64_t = signed long;
 #endif

 using uint8_t  = unsigned char;
 using uint16_t = unsigned short;
 using uint32_t = unsigned int;
-#if ASL_OS_WINDOWS
+#if defined(ASL_OS_WINDOWS)
    using uint64_t = unsigned long long;
-#elif ASL_OS_LINUX
+#elif defined(ASL_OS_LINUX)
    using uint64_t = unsigned long;
 #endif

@ -40,5 +40,25 @@ namespace asl

 enum class byte : uint8_t {};

+template<typename T> struct integer_traits {};
+
+#define ASL_INTEGER_TRAITS(T, MIN, MAX)               \
+    template<> struct integer_traits<T>               \
+    {                                                 \
+        static constexpr T kMin{static_cast<T>(MIN)}; \
+        static constexpr T kMax{static_cast<T>(MAX)}; \
+    }
+
+ASL_INTEGER_TRAITS(uint8_t,   0,                     0xff);
+ASL_INTEGER_TRAITS(uint16_t,  0,                     0xffff);
+ASL_INTEGER_TRAITS(uint32_t,  0,                     0xffff'ffff);
+ASL_INTEGER_TRAITS(uint64_t,  0,                     0xffff'ffff'ffff'ffff);
+ASL_INTEGER_TRAITS(int8_t,   -0x80,                  0x7f);
+ASL_INTEGER_TRAITS(int16_t,  -0x8000,                0x7fff);
+ASL_INTEGER_TRAITS(int32_t,  -0x8000'0000,           0x7fff'ffff);
+ASL_INTEGER_TRAITS(int64_t,  -0x8000'0000'0000'0000, 0x7fff'ffff'ffff'ffff);
+
+#undef ASL_INTEGER_TRAITS
+
 } // namespace asl

--- a/asl/base/meta.hpp
+++ b/asl/base/meta.hpp
@ -25,6 +25,9 @@ struct empty {};

 template<typename T> struct id { using type = T; };

+struct in_place_t {};
+static constexpr in_place_t in_place{};
+
 template<typename... Args> static constexpr isize_t types_count = sizeof...(Args);

 template<typename T, T kValue> struct integral_constant { static constexpr T value = kValue; };
@ -92,12 +95,6 @@ template<typename T> concept trivially_destructible = __is_trivially_destructibl
 template<typename T> concept copyable = copy_constructible<T> && copy_assignable<T>;
 template<typename T> concept moveable = move_constructible<T> && move_assignable<T>;

-template<typename From, typename To>
-concept convertible_to = __is_convertible(From, To);
-
-template<typename Derived, class Base>
-concept derived_from = __is_class(Derived) && __is_class(Base) && convertible_to<const volatile Derived*, const volatile Base*>;
-
 using nullptr_t = decltype(nullptr);

 template<typename T> struct _un_const_helper          { using type = T; };
@ -149,11 +146,22 @@ struct _copy_const_helper<From, To, true> { using type = const To; };
 template<typename From, typename To> using copy_cref_t =
    _copy_ref_helper<From, typename _copy_const_helper<From, un_cvref_t<To>>::type>::type;

+template<typename From, typename To> using copy_const_t = _copy_const_helper<From, un_cvref_t<To>>::type;
+
 template<typename T> struct _is_ptr_helper     : false_type {};
 template<typename T> struct _is_ptr_helper<T*> : true_type {};

 template<typename T> concept is_ptr = _is_ptr_helper<un_cv_t<T>>::value;

+template<typename From, typename To>
+concept convertible_to = __is_convertible(From, To);
+
+template<typename Derived, typename Base>
+concept derived_from = __is_class(Derived) && __is_class(Base) && convertible_to<const volatile Derived*, const volatile Base*>;
+
+template<typename Derived, typename Base>
+concept same_or_derived_from = same_as<un_cvref_t<Derived>, Base> || derived_from<un_cvref_t<Derived>, Base>;
+
 template<typename T> struct _tame_helper { using type = T; };

 #define TAME_HELPER_IMPL(TRAILING)                                  \
@ -194,6 +202,17 @@ template<typename R, typename... Args> struct _is_func_helper<R(Args...)> : true

 template<typename T> concept is_func = _is_func_helper<tame_t<T>>::value;

+template<typename T>             struct _is_member_ptr_helper         : false_type {};
+template<typename C, typename T> struct _is_member_ptr_helper<T C::*> : true_type
+{
+    static constexpr bool kIsFunc = is_func<T>;
+};
+
+template<typename T> concept is_member_ptr = _is_member_ptr_helper<un_cv_t<T>>::value;
+
+template<typename T> concept is_member_func_ptr = is_member_ptr<T> && _is_member_ptr_helper<un_cv_t<T>>::kIsFunc;
+template<typename T> concept is_member_data_ptr = is_member_ptr<T> && !_is_member_ptr_helper<un_cv_t<T>>::kIsFunc;
+
 template<typename T> concept is_object = !is_void<T> && !is_ref<T> && !is_func<T>;

 template<typename T>        struct _array_helper       : false_type { using type = T; };
@ -220,25 +239,111 @@ template<>           struct _is_floating_point_helper<double> : true_type  {};

 template<typename T> concept is_floating_point = _is_floating_point_helper<un_cv_t<T>>::value;

-template<typename T> struct _is_integer_helper           : false_type {};
-template<>           struct _is_integer_helper<int8_t>   : true_type  {};
-template<>           struct _is_integer_helper<int16_t>  : true_type  {};
-template<>           struct _is_integer_helper<int32_t>  : true_type  {};
-template<>           struct _is_integer_helper<int64_t>  : true_type  {};
-template<>           struct _is_integer_helper<uint8_t>  : true_type  {};
-template<>           struct _is_integer_helper<uint16_t> : true_type  {};
-template<>           struct _is_integer_helper<uint32_t> : true_type  {};
-template<>           struct _is_integer_helper<uint64_t> : true_type  {};
+template<typename T> struct _integer_traits
+{
+    static constexpr bool kSigned = false;
+    static constexpr bool kUnsigned = false;
+};

-template<typename T> concept is_integer = _is_integer_helper<un_cv_t<T>>::value;
+template<> struct _integer_traits<uint8_t>
+{
+    static constexpr bool kSigned = false;
+    static constexpr bool kUnsigned = true;
+    using as_signed   = int8_t;
+    using as_unsigned = uint8_t;
+};
+
+template<> struct _integer_traits<uint16_t>
+{
+    static constexpr bool kSigned = false;
+    static constexpr bool kUnsigned = true;
+    using as_signed   = int16_t;
+    using as_unsigned = uint16_t;
+};
+
+template<> struct _integer_traits<uint32_t>
+{
+    static constexpr bool kSigned = false;
+    static constexpr bool kUnsigned = true;
+    using as_signed   = int32_t;
+    using as_unsigned = uint32_t;
+};
+
+template<> struct _integer_traits<uint64_t>
+{
+    static constexpr bool kSigned = false;
+    static constexpr bool kUnsigned = true;
+    using as_signed   = int64_t;
+    using as_unsigned = uint64_t;
+};
+
+template<> struct _integer_traits<int8_t>
+{
+    static constexpr bool kSigned = true;
+    static constexpr bool kUnsigned = false;
+    using as_unsigned = uint8_t;
+    using as_signed   = int8_t;
+};
+
+template<> struct _integer_traits<int16_t>
+{
+    static constexpr bool kSigned = true;
+    static constexpr bool kUnsigned = false;
+    using as_unsigned = uint16_t;
+    using as_signed   = int16_t;
+};
+
+template<> struct _integer_traits<int32_t>
+{
+    static constexpr bool kSigned = true;
+    static constexpr bool kUnsigned = false;
+    using as_unsigned = uint32_t;
+    using as_signed   = int32_t;
+};
+
+template<> struct _integer_traits<int64_t>
+{
+    static constexpr bool kSigned = true;
+    static constexpr bool kUnsigned = false;
+    using as_unsigned = uint64_t;
+    using as_signed   = int64_t;
+};
+
+template<typename T> concept is_signed_integer   = _integer_traits<T>::kSigned;
+template<typename T> concept is_unsigned_integer = _integer_traits<T>::kUnsigned;
+
+template<typename T> concept is_integer = is_signed_integer<T> || is_unsigned_integer<T>;
+
+template<is_integer T> using as_unsigned_integer = _integer_traits<T>::as_unsigned;
+template<is_integer T> using as_signed_integer   = _integer_traits<T>::as_signed;
+
+template<int N>
+struct smallest_unsigned_integer_type_for_width_helper { using type = void; };
+
+template<int N> requires (N >= 1 and N <= 8)
+struct smallest_unsigned_integer_type_for_width_helper<N> { using type = uint8_t; };
+
+template<int N> requires (N >= 9 and N <= 16)
+struct smallest_unsigned_integer_type_for_width_helper<N> { using type = uint16_t; };
+
+template<int N> requires (N >= 17 and N <= 32)
+struct smallest_unsigned_integer_type_for_width_helper<N> { using type = uint32_t; };
+
+template<int N> requires (N >= 33 and N <= 64)
+struct smallest_unsigned_integer_type_for_width_helper<N> { using type = uint64_t; };
+
+template<int N> using smallest_unsigned_integer_type_for_width
+    = smallest_unsigned_integer_type_for_width_helper<N>::type;

 template<typename T> concept is_enum = __is_enum(T);

-template<typename T>     struct is_uniquely_represented : false_type {};
-template<is_integer T>   struct is_uniquely_represented<T> : true_type {};
-template<is_enum T>      struct is_uniquely_represented<T> : true_type {};
+template<is_enum T> using underlying_t = __underlying_type(T);
+
+template<typename T>     struct is_uniquely_represented            : false_type {};
+template<is_integer T>   struct is_uniquely_represented<T>         : true_type {};
+template<is_enum T>      struct is_uniquely_represented<T>         : true_type {};
 template<>               struct is_uniquely_represented<uint128_t> : true_type {};
-template<>               struct is_uniquely_represented<byte> : true_type {};
+template<>               struct is_uniquely_represented<byte>      : true_type {};

 template<typename T> concept uniquely_represented = is_uniquely_represented<un_cv_t<T>>::value;

--- a/asl/base/meta_tests.cpp
+++ b/asl/base/meta_tests.cpp
@ -135,6 +135,12 @@ static_assert(!asl::is_ref<void>);
 static_assert(!asl::is_ref<void()>);
 static_assert(!asl::is_ref<void() const &&>);

+struct MyClass
+{
+    int data;
+    int fn(int x) { return x; } // NOLINT
+};
+
 static_assert(asl::is_ptr<int*>);
 static_assert(asl::is_ptr<const int* const>);
 static_assert(asl::is_ptr<const volatile int*>);
@ -142,6 +148,28 @@ static_assert(!asl::is_ptr<int>);
 static_assert(!asl::is_ptr<void>);
 static_assert(!asl::is_ptr<void()>);
 static_assert(!asl::is_ptr<void() const &&>);
+static_assert(!asl::is_ptr<int MyClass::*>);
+static_assert(!asl::is_ptr<int (MyClass::*)(int)>);
+
+static_assert(!asl::is_member_ptr<int*>);
+static_assert(!asl::is_member_ptr<void()>);
+static_assert(!asl::is_member_ptr<void() const &&>);
+static_assert(asl::is_member_ptr<int MyClass::*>);
+static_assert(asl::is_member_ptr<int (MyClass::*)(int)>);
+
+static_assert(!asl::is_member_data_ptr<int*>);
+static_assert(!asl::is_member_data_ptr<void()>);
+static_assert(!asl::is_member_data_ptr<void() const &&>);
+static_assert(asl::is_member_data_ptr<int MyClass::*>);
+static_assert(!asl::is_member_data_ptr<int (MyClass::*)(int)>);
+
+static_assert(!asl::is_member_func_ptr<int*>);
+static_assert(!asl::is_member_func_ptr<void()>);
+static_assert(!asl::is_member_func_ptr<void() const &&>);
+static_assert(!asl::is_member_func_ptr<int MyClass::*>);
+static_assert(asl::is_member_func_ptr<int (MyClass::*)(int)>);
+static_assert(asl::is_member_func_ptr<int (MyClass::*)(int) const>);
+static_assert(asl::is_member_func_ptr<int (MyClass::*)(int) volatile &&>);

 static_assert(asl::same_as<int, asl::tame_t<int>>);
 static_assert(asl::same_as<int(), asl::tame_t<int()>>);
@ -224,6 +252,8 @@ static_assert(!asl::convertible_to<const int16_t(&)[], int16_t(&)[]>);
 static_assert(!asl::convertible_to<D(&)[], C(&)[]>);

 static_assert(asl::derived_from<Derived, Base>);
+static_assert(asl::derived_from<Derived, Derived>);
+static_assert(asl::derived_from<Base, Base>);
 static_assert(!asl::derived_from<Base, Derived>);
 static_assert(!asl::derived_from<D, C>);
 static_assert(!asl::derived_from<C, D>);
@ -231,9 +261,20 @@ static_assert(!asl::derived_from<uint8_t, uint16_t>);
 static_assert(!asl::derived_from<uint16_t, uint8_t>);
 static_assert(!asl::derived_from<int, int>);

+static_assert(asl::same_or_derived_from<Derived, Base>);
+static_assert(asl::same_or_derived_from<Derived, Derived>);
+static_assert(asl::same_or_derived_from<Base, Base>);
+static_assert(!asl::same_or_derived_from<Base, Derived>);
+static_assert(!asl::same_or_derived_from<D, C>);
+static_assert(!asl::same_or_derived_from<C, D>);
+static_assert(!asl::same_or_derived_from<uint8_t, uint16_t>);
+static_assert(!asl::same_or_derived_from<uint16_t, uint8_t>);
+static_assert(asl::same_or_derived_from<int, int>);
+
 static_assert(!asl::is_const<int>);
 static_assert(asl::is_const<const int>);
 static_assert(!asl::is_const<const int*>);
+static_assert(!asl::is_const<const int&>);
 static_assert(asl::is_const<int* const>);

 static_assert(asl::is_floating_point<float>);
@ -322,6 +363,15 @@ static_assert(asl::same_as<asl::copy_cref_t<const int&, const float>, const floa
 static_assert(asl::same_as<asl::copy_cref_t<const int&, float&&>, const float&>);
 static_assert(asl::same_as<asl::copy_cref_t<const int&, const float&>, const float&>);

+static_assert(asl::same_as<asl::copy_const_t<int, float>, float>);
+static_assert(asl::same_as<asl::copy_const_t<int, const float>, float>);
+
+static_assert(asl::same_as<asl::copy_const_t<const int, float>, const float>);
+static_assert(asl::same_as<asl::copy_const_t<const int, const float>, const float>);
+
+static_assert(asl::same_as<asl::copy_const_t<const int*, float>, float>);
+static_assert(asl::same_as<asl::copy_const_t<int* const, float>, const float>);
+
 static_assert(asl::same_as<asl::decay_t<int>, int>);
 static_assert(!asl::same_as<asl::decay_t<int>, float>);
 static_assert(asl::same_as<asl::decay_t<int&>, int>);
@ -332,3 +382,46 @@ static_assert(!asl::same_as<asl::decay_t<int[4][2]>, int*>);
 static_assert(!asl::same_as<asl::decay_t<int[4][2]>, int**>);
 static_assert(asl::same_as<asl::decay_t<int[4][2]>, int(*)[2]>);
 static_assert(asl::same_as<asl::decay_t<int(int)>, int(*)(int)>);
+
+enum EnumU8 : uint8_t {};
+enum EnumI64 : int64_t {};
+
+static_assert(asl::same_as<asl::underlying_t<EnumU8>, uint8_t>);
+static_assert(asl::same_as<asl::underlying_t<EnumI64>, int64_t>);
+
+static_assert(!asl::is_integer<EnumU8>);
+static_assert(!asl::is_integer<EnumI64>);
+
+static_assert(asl::same_as<asl::as_unsigned_integer<uint8_t>,  uint8_t>);
+static_assert(asl::same_as<asl::as_unsigned_integer<uint16_t>, uint16_t>);
+static_assert(asl::same_as<asl::as_unsigned_integer<uint32_t>, uint32_t>);
+static_assert(asl::same_as<asl::as_unsigned_integer<uint64_t>, uint64_t>);
+
+static_assert(asl::same_as<asl::as_unsigned_integer<int8_t>,  uint8_t>);
+static_assert(asl::same_as<asl::as_unsigned_integer<int16_t>, uint16_t>);
+static_assert(asl::same_as<asl::as_unsigned_integer<int32_t>, uint32_t>);
+static_assert(asl::same_as<asl::as_unsigned_integer<int64_t>, uint64_t>);
+
+static_assert(asl::same_as<asl::as_signed_integer<uint8_t>,  int8_t>);
+static_assert(asl::same_as<asl::as_signed_integer<uint16_t>, int16_t>);
+static_assert(asl::same_as<asl::as_signed_integer<uint32_t>, int32_t>);
+static_assert(asl::same_as<asl::as_signed_integer<uint64_t>, int64_t>);
+
+static_assert(asl::same_as<asl::as_signed_integer<int8_t>,  int8_t>);
+static_assert(asl::same_as<asl::as_signed_integer<int16_t>, int16_t>);
+static_assert(asl::same_as<asl::as_signed_integer<int32_t>, int32_t>);
+static_assert(asl::same_as<asl::as_signed_integer<int64_t>, int64_t>);
+
+static_assert(asl::same_as<asl::smallest_unsigned_integer_type_for_width<1>, uint8_t>);
+static_assert(asl::same_as<asl::smallest_unsigned_integer_type_for_width<2>, uint8_t>);
+static_assert(asl::same_as<asl::smallest_unsigned_integer_type_for_width<4>, uint8_t>);
+static_assert(asl::same_as<asl::smallest_unsigned_integer_type_for_width<8>, uint8_t>);
+static_assert(asl::same_as<asl::smallest_unsigned_integer_type_for_width<12>, uint16_t>);
+static_assert(asl::same_as<asl::smallest_unsigned_integer_type_for_width<16>, uint16_t>);
+static_assert(asl::same_as<asl::smallest_unsigned_integer_type_for_width<20>, uint32_t>);
+static_assert(asl::same_as<asl::smallest_unsigned_integer_type_for_width<30>, uint32_t>);
+static_assert(asl::same_as<asl::smallest_unsigned_integer_type_for_width<31>, uint32_t>);
+static_assert(asl::same_as<asl::smallest_unsigned_integer_type_for_width<32>, uint32_t>);
+static_assert(asl::same_as<asl::smallest_unsigned_integer_type_for_width<50>, uint64_t>);
+static_assert(asl::same_as<asl::smallest_unsigned_integer_type_for_width<63>, uint64_t>);
+static_assert(asl::same_as<asl::smallest_unsigned_integer_type_for_width<64>, uint64_t>);
--- a/asl/base/numeric.hpp
+++ b/asl/base/numeric.hpp
@ -0,0 +1,101 @@
+// Copyright 2025 Steven Le Rouzic
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#pragma once
+
+#include "asl/base/integers.hpp"
+#include "asl/base/float.hpp"
+#include "asl/base/bit.hpp"
+#include "asl/base/meta.hpp"
+#include "asl/base/assert.hpp"
+
+namespace asl
+{
+
+template<is_integer T>
+constexpr bool is_pow2(T x)
+{
+    using unsigned_type = as_unsigned_integer<T>;
+    return x > 0 && has_single_bit(static_cast<unsigned_type>(x));
+}
+
+template<is_integer T>
+constexpr T round_down_pow2(T x, T div)
+{
+    ASL_ASSERT(is_pow2(div));
+    return x & (-div);
+}
+
+template<is_integer T>
+constexpr T round_up_pow2(T x, T div)
+{
+    ASL_ASSERT(is_pow2(div));
+    return (x + (div - 1)) & (-div);
+}
+
+template<typename T>
+concept is_numeric = is_integer<T> || is_floating_point<T>;
+
+template<is_numeric T>
+constexpr T min(T a, T b)
+{
+    return (a <= b) ? a : b;
+}
+
+template<is_numeric T>
+constexpr T max(T a, T b)
+{
+    return (a >= b) ? a : b;
+}
+
+template<is_numeric T>
+constexpr T clamp(T x, T a, T b)
+{
+    return min(max(x, a), b);
+}
+
+constexpr float32_t abs(float32_t x) { return __builtin_fabsf(x); }
+constexpr float64_t abs(float64_t x) { return __builtin_fabs(x); }
+
+template<is_floating_point T>
+bool are_nearly_equal(T a, T b)
+{
+    // This is a fast path for identical values and correctly handles
+    // the case where +0.0 == -0.0.
+    #pragma clang diagnostic push
+    #pragma clang diagnostic ignored "-Wfloat-equal"
+    if (a == b) { return true; }
+    #pragma clang diagnostic pop
+
+    // NaNs are never equal to anything, including themselves.
+    if (is_nan(a) || is_nan(b)) { return false; }
+
+    // Infinities are only equal if they are identical (which is handled by the
+    // `a == b` check above). If one is infinity and the other is not, they
+    // are not equal. The relative comparison below would fail with infinities.
+    if (is_infinity(a) || is_infinity(b)) { return false; }
+
+    static constexpr T kMin = float_traits<T>::kSmallest;
+    static constexpr T kEps = float_traits<T>::kEpsilon;
+
+    const T abs_a = abs(a);
+    const T abs_b = abs(b);
+    const T abs_diff = abs(a - b);
+
+    // The relative error comparison (`|a-b| <= ε * max(|a|, |b|)`) breaks
+    // down when `a` and `b` are near zero. In this case, we switch to an
+    // absolute error comparison. `DBL_MIN` is the smallest positive
+    // normalized double, so it's a good threshold for this check.
+    if (abs_a < kMin || abs_b < kMin)
+    {
+        return abs_diff < kEps;
+    }
+
+    // For all other cases, we use the standard relative error formula.
+    // The error is scaled by the magnitude of the numbers.
+    return abs_diff <= kEps * max(abs_a, abs_b);
+}
+
+} // namespace asl
+
--- a/asl/base/numeric_tests.cpp
+++ b/asl/base/numeric_tests.cpp
@ -0,0 +1,68 @@
+// Copyright 2025 Steven Le Rouzic
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#include "asl/base/numeric.hpp"
+
+#include "asl/testing/testing.hpp"
+
+ASL_TEST(is_pow2)
+{
+    ASL_TEST_EXPECT(asl::is_pow2(4));
+    ASL_TEST_EXPECT(asl::is_pow2(65536));
+    ASL_TEST_EXPECT(!asl::is_pow2(6));
+    ASL_TEST_EXPECT(!asl::is_pow2(1978));
+    ASL_TEST_EXPECT(!asl::is_pow2(0));
+    ASL_TEST_EXPECT(asl::is_pow2(4U));
+    ASL_TEST_EXPECT(asl::is_pow2(uint64_t{65536}));
+}
+
+ASL_TEST(round_down_pow2) // NOLINT
+{
+    ASL_TEST_EXPECT(asl::round_down_pow2(0, 1) == 0);
+    ASL_TEST_EXPECT(asl::round_down_pow2(1, 1) == 1);
+    ASL_TEST_EXPECT(asl::round_down_pow2(2, 1) == 2);
+    ASL_TEST_EXPECT(asl::round_down_pow2(3, 1) == 3);
+    ASL_TEST_EXPECT(asl::round_down_pow2(-1, 1) == -1);
+    ASL_TEST_EXPECT(asl::round_down_pow2(-2, 1) == -2);
+    ASL_TEST_EXPECT(asl::round_down_pow2(-3, 1) == -3);
+
+    ASL_TEST_EXPECT(asl::round_down_pow2(0U, 1U) == 0U);
+    ASL_TEST_EXPECT(asl::round_down_pow2(1U, 1U) == 1U);
+    ASL_TEST_EXPECT(asl::round_down_pow2(2U, 1U) == 2U);
+    ASL_TEST_EXPECT(asl::round_down_pow2(3U, 1U) == 3U);
+
+    ASL_TEST_EXPECT(asl::round_down_pow2(0, 16) == 0);
+    ASL_TEST_EXPECT(asl::round_down_pow2(1, 16) == 0);
+    ASL_TEST_EXPECT(asl::round_down_pow2(8, 16) == 0);
+    ASL_TEST_EXPECT(asl::round_down_pow2(15, 16) == 0);
+    ASL_TEST_EXPECT(asl::round_down_pow2(16, 16) == 16);
+    ASL_TEST_EXPECT(asl::round_down_pow2(17, 16) == 16);
+    ASL_TEST_EXPECT(asl::round_down_pow2(255, 16) == 240);
+    ASL_TEST_EXPECT(asl::round_down_pow2(-255, 16) == -256);
+}
+
+ASL_TEST(round_up_pow2) // NOLINT
+{
+    ASL_TEST_EXPECT(asl::round_up_pow2(0, 1) == 0);
+    ASL_TEST_EXPECT(asl::round_up_pow2(1, 1) == 1);
+    ASL_TEST_EXPECT(asl::round_up_pow2(2, 1) == 2);
+    ASL_TEST_EXPECT(asl::round_up_pow2(3, 1) == 3);
+    ASL_TEST_EXPECT(asl::round_up_pow2(-1, 1) == -1);
+    ASL_TEST_EXPECT(asl::round_up_pow2(-2, 1) == -2);
+    ASL_TEST_EXPECT(asl::round_up_pow2(-3, 1) == -3);
+
+    ASL_TEST_EXPECT(asl::round_up_pow2(0U, 1U) == 0U);
+    ASL_TEST_EXPECT(asl::round_up_pow2(1U, 1U) == 1U);
+    ASL_TEST_EXPECT(asl::round_up_pow2(2U, 1U) == 2U);
+    ASL_TEST_EXPECT(asl::round_up_pow2(3U, 1U) == 3U);
+
+    ASL_TEST_EXPECT(asl::round_up_pow2(0, 16) == 0);
+    ASL_TEST_EXPECT(asl::round_up_pow2(1, 16) == 16);
+    ASL_TEST_EXPECT(asl::round_up_pow2(8, 16) == 16);
+    ASL_TEST_EXPECT(asl::round_up_pow2(15, 16) == 16);
+    ASL_TEST_EXPECT(asl::round_up_pow2(16, 16) == 16);
+    ASL_TEST_EXPECT(asl::round_up_pow2(17, 16) == 32);
+    ASL_TEST_EXPECT(asl::round_up_pow2(255, 16) == 256);
+    ASL_TEST_EXPECT(asl::round_up_pow2(-255, 16) == -240);
+}
--- a/asl/base/utility.hpp
+++ b/asl/base/utility.hpp
@ -47,9 +47,6 @@ template<typename T>
 namespace asl
 {

-struct in_place_t {};
-static constexpr in_place_t in_place{};
-
 template<moveable T>
 constexpr void swap(T& a, T& b)
 {
@ -72,37 +69,10 @@ constexpr U bit_cast(T value) requires (sizeof(T) == sizeof(U))
    return __builtin_bit_cast(U, value);
 }

-template<typename T>
-constexpr T min(T a, T b)
+template<is_enum T>
+constexpr auto to_underlying(T value)
 {
-    return (a <= b) ? a : b;
-}
-
-template<typename T>
-constexpr T max(T a, T b)
-{
-    return (a >= b) ? a : b;
-}
-
-constexpr uint64_t round_up_pow2(uint64_t v)
-{
-    ASL_ASSERT(v <= 0x8000'0000'0000'0000);
-
-    v -= 1;
-
-    v |= v >> 1U;
-    v |= v >> 2U;
-    v |= v >> 4U;
-    v |= v >> 8U;
-    v |= v >> 16U;
-    v |= v >> 32U;
-
-    return v + 1;
-}
-
-constexpr bool is_pow2(isize_t v)
-{
-    return v > 0 && ((v - 1) & v) == 0; // NOLINT
+    return static_cast<underlying_t<T>>(value);
 }

 // NOLINTBEGIN(*-macro-parentheses)
--- a/asl/base/utility_tests.cpp
+++ b/asl/base/utility_tests.cpp
@ -81,3 +81,20 @@ ASL_TEST(forward_like)
    ASL_TEST_EXPECT(test_fwd_like<int&&>(9) == 4);
 }

+enum class Enum : int // NOLINT
+{
+    kOne = 1,
+    kTwo = 2,
+};
+
+enum Enum2 : int // NOLINT
+{
+    kOne = 1,
+    kTwo = 2,
+};
+
+static_assert(asl::to_underlying(Enum::kOne) == 1);
+static_assert(asl::to_underlying(Enum::kTwo) == 2);
+static_assert(asl::to_underlying(kOne) == 1);
+static_assert(asl::to_underlying(kTwo) == 2);
+
--- a/asl/containers/BUILD.bazel
+++ b/asl/containers/BUILD.bazel
@ -13,6 +13,7 @@ cc_library(
    ],
    deps = [
        "//asl/memory",
+        "//asl/memory:allocator",
        "//asl/base",
        "//asl/types:span",
        "//asl/hashing",
@ -20,6 +21,22 @@ cc_library(
    visibility = ["//visibility:public"],
 )

+cc_library(
+    name = "chunked_buffer",
+    hdrs = [
+        "chunked_buffer.hpp",
+    ],
+    deps = [
+        "//asl/memory",
+        "//asl/memory:allocator",
+        "//asl/base",
+        "//asl/containers:buffer",
+        "//asl/types:array",
+        "//asl/types:maybe_uninit",
+    ],
+    visibility = ["//visibility:public"],
+)
+
 cc_library(
    name = "hash_set",
    hdrs = [
@ -28,6 +45,7 @@ cc_library(
    deps = [
        "//asl/base",
        "//asl/memory",
+        "//asl/memory:allocator",
        "//asl/types:maybe_uninit",
        "//asl/hashing",
    ],
@ -42,6 +60,7 @@ cc_library(
    deps = [
        "//asl/base",
        "//asl/memory",
+        "//asl/memory:allocator",
        "//asl/hashing",
        ":hash_set",
    ],
@ -72,6 +91,7 @@ cc_library(
    ],
 ) for name in [
    "buffer",
+    "chunked_buffer",
    "hash_map",
    "hash_set",
    "intrusive_list",
--- a/asl/containers/buffer.hpp
+++ b/asl/containers/buffer.hpp
@ -9,13 +9,15 @@
 #include "asl/memory/memory.hpp"
 #include "asl/base/annotations.hpp"
 #include "asl/base/assert.hpp"
+#include "asl/base/bit.hpp"
 #include "asl/types/span.hpp"
 #include "asl/hashing/hash.hpp"

 namespace asl
 {

-template<is_object T, allocator Allocator = DefaultAllocator>
+template<typename T, allocator Allocator = DefaultAllocator>
+requires is_object<T> && moveable<T>
 class buffer
 {
    T*         m_data{};
@ -89,7 +91,7 @@ private:
        return is_on_heap(load_size_encoded());
    }

-    constexpr T* push_uninit()
+    constexpr void* push_uninit()
    {
        const isize_t sz = size();
        resize_uninit_inner(sz + 1);
@ -98,10 +100,13 @@ private:

    constexpr void resize_uninit_inner(isize_t new_size)
    {
-        const isize_t old_size = size();
-        if (!trivially_destructible<T> && new_size < old_size)
+        if constexpr (!trivially_destructible<T>)
        {
-            destroy_n(data() + new_size, old_size - new_size);
+            const isize_t old_size = size();
+            if (new_size < old_size)
+            {
+                destroy_n(data() + new_size, old_size - new_size);
+            }
        }
        reserve_capacity(new_size);
        set_size(new_size);
@ -134,18 +139,26 @@ private:
    {
        if (other.is_on_heap())
        {
+            // If the other in on heap, destroy here and adopt their
+            // data. We'll soon adopt the allocator as well.
            destroy();
            m_data = other.m_data;
            m_capacity = other.m_capacity;
            store_size_encoded(other.load_size_encoded());
        }
-        else if (trivially_move_constructible<T>)
-        {
-            destroy();
-            asl::memcpy(this, &other, kInlineRegionSize);
-        }
        else if (!assign || m_allocator == other.m_allocator)
        {
+            // If allocators are compatible, we can move other's inline
+            // data here, even if it's on heap here, because that
+            // memory can be freed by other's allocator, which we will
+            // soon adopt.
+            //
+            // @Note There is an argument to be made for not doing this and
+            // instead destroying our data here and moving into inline
+            // storage, which frees one allocation. But also this avoids
+            // freeing. So I don't know.
+            // Maybe If this storage is much much larger than the inline
+            // data, it's worth freeing.
            const isize_t other_n = other.size();
            const isize_t this_n = size();
            resize_uninit_inner(other_n);
@ -161,11 +174,28 @@ private:
        }
        else
        {
+            // Otherwise, if we have to free, because the allocators are
+            // not compatible, well we free and move into our inline
+            // storage region.
+            // There is an optimization here when the data is trivially
+            // move constructible (which implies trivially destructible),
+            // we copy the whole inline region, which includes the size.
+            // Very magic.
+
            destroy();
-            const isize_t n = other.size();
-            ASL_ASSERT(n <= kInlineCapacity);
-            relocate_uninit_n(data(), other.data(), n);
-            set_size_inline(n);
+            if constexpr (trivially_move_constructible<T>)
+            {
+                ASL_ASSERT(!is_on_heap());
+                asl::memcpy(this, &other, kInlineRegionSize);
+            }
+            else
+            {
+                const isize_t n = other.size();
+                ASL_ASSERT(n <= kInlineCapacity);
+                resize_uninit_inner(n);
+                ASL_ASSERT(!is_on_heap());
+                relocate_uninit_n(data(), other.data(), n);
+            }
        }

        other.set_size_inline(0);
@ -243,7 +273,6 @@ public:
    }

    constexpr buffer(buffer&& other)
-        requires moveable<T>
        : buffer(std::move(other.m_allocator))
    {
        move_from_other(std::move(other), false);
@ -258,7 +287,6 @@ public:
    }

    constexpr buffer& operator=(buffer&& other)
-        requires moveable<T>
    {
        if (&other == this) { return *this; }
        move_from_other(std::move(other), true);
@ -270,6 +298,14 @@ public:
        destroy();
    }

+    constexpr Allocator allocator_copy() const
+        requires copy_constructible<Allocator>
+    {
+        return m_allocator;
+    }
+
+    constexpr Allocator& allocator() { return m_allocator; }
+
    [[nodiscard]] constexpr isize_t size() const
    {
        return decode_size(load_size_encoded());
@ -315,12 +351,11 @@ public:
    void reserve_capacity(isize_t new_capacity)
    {
        ASL_ASSERT(new_capacity >= 0);
-        ASL_ASSERT_RELEASE(new_capacity <= 0x4000'0000'0000'0000);

        if (new_capacity <= capacity()) { return; }
        ASL_ASSERT(new_capacity > kInlineCapacity);

-        new_capacity = static_cast<isize_t>(round_up_pow2(static_cast<uint64_t>(new_capacity)));
+        new_capacity = static_cast<isize_t>(bit_ceil(static_cast<uint64_t>(new_capacity)));

        T* old_data = data();
        const isize_t old_capacity = capacity();
@ -352,17 +387,16 @@ public:
    }

    constexpr void resize_uninit(isize_t new_size)
-        requires trivially_default_constructible<T> && trivially_destructible<T>
+        requires trivially_default_constructible<T>
    {
-        reserve_capacity(new_size);
-        set_size(new_size);
+        resize_uninit_inner(new_size);
    }

    constexpr void resize_zero(isize_t new_size)
-        requires trivially_default_constructible<T> && trivially_destructible<T>
+        requires trivially_default_constructible<T>
    {
        const isize_t old_size = size();
-        resize_uninit(new_size);
+        resize_uninit_inner(new_size);

        if (new_size > old_size)
        {
@ -373,7 +407,14 @@ public:
    void resize(isize_t new_size)
        requires default_constructible<T>
    {
-        resize_inner(new_size);
+        if constexpr (trivially_default_constructible<T>)
+        {
+            resize_zero(new_size);
+        }
+        else
+        {
+            resize_inner(new_size);
+        }
    }

    void resize(isize_t new_size, const T& value)
@ -384,14 +425,14 @@ public:
    constexpr T& push(auto&&... args)
        requires constructible_from<T, decltype(args)&&...>
    {
-        T* uninit = push_uninit();
+        void* uninit = push_uninit();
        T* init = construct_at<T>(uninit, std::forward<decltype(args)>(args)...);
        return *init;
    }

    auto data(this auto&& self)
    {
-        using return_type = un_ref_t<copy_cref_t<decltype(self), T>>*;
+        using return_type = as_ptr_t<copy_const_t<un_ref_t<decltype(self)>, T>>;
        // NOLINTNEXTLINE(*-reinterpret-cast)
        auto&& buffer = reinterpret_cast<copy_cref_t<decltype(self), class buffer>>(self);
        if constexpr (kInlineCapacity == 0)
@ -409,13 +450,13 @@ public:

    constexpr auto begin(this auto&& self)
    {
-        using type = un_ref_t<copy_cref_t<decltype(self), T>>;
+        using type = copy_const_t<un_ref_t<decltype(self)>, T>;
        return contiguous_iterator<type>{self.data()};
    }

    constexpr auto end(this auto&& self)
    {
-        using type = un_ref_t<copy_cref_t<decltype(self), T>>;
+        using type = copy_const_t<un_ref_t<decltype(self)>, T>;
        return contiguous_iterator<type>{self.data() + self.size()};
    }

@ -431,13 +472,13 @@ public:

    constexpr auto as_span(this auto&& self)
    {
-        using type = un_ref_t<copy_cref_t<decltype(self), T>>;
+        using type = copy_const_t<un_ref_t<decltype(self)>, T>;
        return span<type>{self.data(), self.size()};
    }

    constexpr auto&& operator[](this auto&& self, isize_t i)
    {
-        ASL_ASSERT(i >= 0 && i <= self.size());
+        ASL_ASSERT(i >= 0 && i < self.size());
        return std::forward_like<decltype(self)>(std::forward<decltype(self)>(self).data()[i]);
    }

--- a/asl/containers/buffer_tests.cpp
+++ b/asl/containers/buffer_tests.cpp
@ -6,6 +6,7 @@

 #include "asl/testing/testing.hpp"
 #include "asl/tests/types.hpp"
+#include "asl/tests/counting_allocator.hpp"

 struct Big
 {
@ -14,6 +15,7 @@ struct Big

 static_assert(asl::buffer<int32_t>::kInlineCapacity == 5);
 static_assert(asl::buffer<int64_t>::kInlineCapacity == 2);
+static_assert(asl::buffer<void*>::kInlineCapacity == 2);
 static_assert(asl::buffer<char>::kInlineCapacity == 23);
 static_assert(asl::buffer<Big>::kInlineCapacity == 0);

@ -30,32 +32,6 @@ ASL_TEST(default_size)
    ASL_TEST_EXPECT(b2.data() == nullptr);
 }

-struct CounterAllocator
-{
-    isize_t* count;
-
-    [[nodiscard]]
-    void* alloc(const asl::layout& layout) const
-    {
-        *count += 1;
-        return asl::GlobalHeap::alloc(layout);
-    }
-
-    void* realloc(void* ptr, const asl::layout& old, const asl::layout& new_layout) const
-    {
-        *count += 1;
-        return asl::GlobalHeap::realloc(ptr, old, new_layout);
-    }
-
-    static void dealloc(void* ptr, const asl::layout& layout)
-    {
-        asl::GlobalHeap::dealloc(ptr, layout);
-    }
-
-    constexpr bool operator==(const CounterAllocator&) const { return true; }
-};
-static_assert(asl::allocator<CounterAllocator>);
-
 struct IncompatibleAllocator
 {
    static void* alloc(const asl::layout& layout)
@ -80,31 +56,31 @@ static_assert(asl::allocator<IncompatibleAllocator>);
 // NOLINTNEXTLINE(*-complexity)
 ASL_TEST(reserve_capacity)
 {
-    isize_t count = 0;
-    asl::buffer<int32_t, CounterAllocator> b(CounterAllocator{&count});
+    CountingAllocator::Stats stats;
+    asl::buffer<int32_t, CountingAllocator> b(CountingAllocator{&stats});
    ASL_TEST_EXPECT(b.size() == 0);
    ASL_TEST_EXPECT(b.capacity() == 5);
-    ASL_TEST_EXPECT(count == 0);
+    ASL_TEST_EXPECT(stats.any_alloc_count() == 0);

    b.reserve_capacity(4);
    ASL_TEST_EXPECT(b.size() == 0);
    ASL_TEST_EXPECT(b.capacity() == 5);
-    ASL_TEST_EXPECT(count == 0);
+    ASL_TEST_EXPECT(stats.any_alloc_count() == 0);

    b.reserve_capacity(12);
    ASL_TEST_EXPECT(b.size() == 0);
    ASL_TEST_EXPECT(b.capacity() >= 12);
-    ASL_TEST_EXPECT(count == 1);
+    ASL_TEST_EXPECT(stats.any_alloc_count() == 1);

    b.reserve_capacity(13);
    ASL_TEST_EXPECT(b.size() == 0);
    ASL_TEST_EXPECT(b.capacity() >= 13);
-    ASL_TEST_EXPECT(count == 1);
+    ASL_TEST_EXPECT(stats.any_alloc_count() == 1);

    b.reserve_capacity(130);
    ASL_TEST_EXPECT(b.size() == 0);
    ASL_TEST_EXPECT(b.capacity() >= 130);
-    ASL_TEST_EXPECT(count == 2);
+    ASL_TEST_EXPECT(stats.any_alloc_count() == 2);
 }

 // NOLINTNEXTLINE(*-complexity)
@ -159,13 +135,19 @@ struct MoveableType
    MoveableType(const MoveableType&) = delete;
    MoveableType(MoveableType&& other)  : moved{other.moved + 1}, value{other.value} {}
    MoveableType& operator=(const MoveableType&) = delete;
-    MoveableType& operator=(MoveableType&&) = delete;
+    MoveableType& operator=(MoveableType&& other)
+    {
+        if (this == &other) { return *this; }
+        moved = other.moved + 1;
+        value = other.value;
+        return *this;
+    }
    ~MoveableType() = default;
 };
 static_assert(!asl::trivially_copy_constructible<MoveableType>);
 static_assert(!asl::trivially_move_constructible<MoveableType>);
 static_assert(!asl::copyable<MoveableType>);
-static_assert(asl::move_constructible<MoveableType>);
+static_assert(asl::moveable<MoveableType>);

 // NOLINTNEXTLINE(*-complexity)
 ASL_TEST(push_move)
@ -213,6 +195,30 @@ ASL_TEST(push_move)
    ASL_TEST_EXPECT(b[3].moved == 1);
    ASL_TEST_EXPECT(b[4].value == 4);
    ASL_TEST_EXPECT(b[4].moved == 0);
+
+    asl::buffer<MoveableType> b2 = std::move(b);
+    ASL_TEST_EXPECT(b2[0].value == 0);
+    ASL_TEST_EXPECT(b2[0].moved == 2);
+    ASL_TEST_EXPECT(b2[1].value == 1);
+    ASL_TEST_EXPECT(b2[1].moved == 2);
+    ASL_TEST_EXPECT(b2[2].value == 2);
+    ASL_TEST_EXPECT(b2[2].moved == 1);
+    ASL_TEST_EXPECT(b2[3].value == 3);
+    ASL_TEST_EXPECT(b2[3].moved == 1);
+    ASL_TEST_EXPECT(b2[4].value == 4);
+    ASL_TEST_EXPECT(b2[4].moved == 0);
+
+    b = std::move(b2);
+    ASL_TEST_EXPECT(b[0].value == 0);
+    ASL_TEST_EXPECT(b[0].moved == 2);
+    ASL_TEST_EXPECT(b[1].value == 1);
+    ASL_TEST_EXPECT(b[1].moved == 2);
+    ASL_TEST_EXPECT(b[2].value == 2);
+    ASL_TEST_EXPECT(b[2].moved == 1);
+    ASL_TEST_EXPECT(b[3].value == 3);
+    ASL_TEST_EXPECT(b[3].moved == 1);
+    ASL_TEST_EXPECT(b[4].value == 4);
+    ASL_TEST_EXPECT(b[4].moved == 0);
 }

 ASL_TEST(clear)
@ -369,21 +375,21 @@ ASL_TEST(move_assign_from_heap)

 ASL_TEST(move_assign_trivial_heap_to_inline)
 {
-    isize_t alloc_count = 0;
-    asl::buffer<int64_t, CounterAllocator> buf{CounterAllocator{&alloc_count}};
-    asl::buffer<int64_t, CounterAllocator> buf2{CounterAllocator{&alloc_count}};
+    CountingAllocator::Stats stats;
+    asl::buffer<int64_t, CountingAllocator> buf{CountingAllocator{&stats}};
+    asl::buffer<int64_t, CountingAllocator> buf2{CountingAllocator{&stats}};

    buf.push(1);
    buf.push(2);
-    ASL_TEST_EXPECT(alloc_count == 0);
+    ASL_TEST_EXPECT(stats.any_alloc_count() == 0);

    buf2.push(3);
    buf2.push(4);
    buf2.push(5);
-    ASL_TEST_EXPECT(alloc_count == 1);
+    ASL_TEST_EXPECT(stats.any_alloc_count() == 1);

    buf = std::move(buf2);
-    ASL_TEST_EXPECT(alloc_count == 1);
+    ASL_TEST_EXPECT(stats.any_alloc_count() == 1);

    ASL_TEST_EXPECT(buf.size() == 3);
    ASL_TEST_EXPECT(buf[0] == 3);
@ -393,21 +399,21 @@ ASL_TEST(move_assign_trivial_heap_to_inline)

 ASL_TEST(move_assign_trivial_inline_to_heap)
 {
-    isize_t alloc_count = 0;
-    asl::buffer<int64_t, CounterAllocator> buf{CounterAllocator{&alloc_count}};
-    asl::buffer<int64_t, CounterAllocator> buf2{CounterAllocator{&alloc_count}};
+    CountingAllocator::Stats stats;
+    asl::buffer<int64_t, CountingAllocator> buf{CountingAllocator{&stats}};
+    asl::buffer<int64_t, CountingAllocator> buf2{CountingAllocator{&stats}};

    buf.push(1);
    buf.push(2);
-    ASL_TEST_EXPECT(alloc_count == 0);
+    ASL_TEST_EXPECT(stats.any_alloc_count() == 0);

    buf2.push(3);
    buf2.push(4);
    buf2.push(5);
-    ASL_TEST_EXPECT(alloc_count == 1);
+    ASL_TEST_EXPECT(stats.any_alloc_count() == 1);

    buf2 = std::move(buf);
-    ASL_TEST_EXPECT(alloc_count == 1);
+    ASL_TEST_EXPECT(stats.any_alloc_count() == 1);

    ASL_TEST_EXPECT(buf2.size() == 2);
    ASL_TEST_EXPECT(buf2[0] == 1);
@ -436,16 +442,16 @@ ASL_TEST(move_assign_inline_to_heap)
        ASL_TEST_EXPECT(buf2.size() == 2);
        ASL_TEST_EXPECT(d[0] == false);
        ASL_TEST_EXPECT(d[1] == false);
-        ASL_TEST_EXPECT(d[2] == false); // moved but not destroyed
-        ASL_TEST_EXPECT(d[3] == false); // moved but not destroyed
+        ASL_TEST_EXPECT(d[2] == true);
+        ASL_TEST_EXPECT(d[3] == true);
        ASL_TEST_EXPECT(d[4] == true);
        ASL_TEST_EXPECT(d[5] == true);
    }

    ASL_TEST_EXPECT(d[0] == true);
    ASL_TEST_EXPECT(d[1] == true);
-    ASL_TEST_EXPECT(d[2] == false); // moved but not destroyed
-    ASL_TEST_EXPECT(d[3] == false); // moved but not destroyed
+    ASL_TEST_EXPECT(d[2] == true);
+    ASL_TEST_EXPECT(d[3] == true);
    ASL_TEST_EXPECT(d[4] == true);
    ASL_TEST_EXPECT(d[5] == true);
 }
@ -605,3 +611,6 @@ ASL_TEST(resize_zero)
    }
 }

+static_assert(asl::same_as<decltype(asl::declval<asl::buffer<int>>().data()), int*>);
+static_assert(asl::same_as<decltype(asl::declval<const asl::buffer<int>>().data()), const int*>);
+
--- a/asl/containers/chunked_buffer.hpp
+++ b/asl/containers/chunked_buffer.hpp
@ -0,0 +1,405 @@
+// Copyright 2025 Steven Le Rouzic
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#pragma once
+
+#include "asl/base/utility.hpp"
+#include "asl/base/assert.hpp"
+#include "asl/base/numeric.hpp"
+#include "asl/containers/buffer.hpp"
+#include "asl/memory/allocator.hpp"
+#include "asl/types/array.hpp"
+#include "asl/types/maybe_uninit.hpp"
+
+namespace asl
+{
+
+template<
+    is_object T,
+    isize_t kChunkSize,
+    allocator Allocator = DefaultAllocator>
+class chunked_buffer
+{
+    static_assert(kChunkSize > 0 && is_pow2(kChunkSize));
+
+    using Chunk = array<maybe_uninit<T>, kChunkSize>;
+
+    static constexpr isize_t chunk_index(isize_t i)
+    {
+        static constexpr int kChunkSizeLog2 = countr_zero(uint64_t{kChunkSize});
+        return i >> kChunkSizeLog2;
+    }
+
+    static constexpr isize_t index_in_chunk(isize_t i)
+    {
+        static constexpr isize_t kMask = kChunkSize - 1;
+        return i & kMask;
+    }
+
+    struct PerChunkIterator
+    {
+        isize_t from_chunk;
+        isize_t to_chunk;
+
+        isize_t from_index_in_chunk;
+        isize_t to_index_in_chunk;
+
+        [[nodiscard]] constexpr bool has_more() const
+        {
+            return from_chunk <= to_chunk;
+        }
+
+        void advance()
+        {
+            from_chunk += 1;
+            from_index_in_chunk = 0;
+        }
+
+        [[nodiscard]] constexpr isize_t chunk() const { return from_chunk; }
+
+        span<maybe_uninit<T>> make_span(Chunk& chunk) const
+        {
+            isize_t from = from_index_in_chunk;
+            isize_t to = (from_chunk == to_chunk) ? to_index_in_chunk : kChunkSize - 1;
+            return chunk.as_span().subspan(from, to - from + 1);
+        }
+    };
+
+    PerChunkIterator make_index_iterator(isize_t from, isize_t to)
+    {
+        return PerChunkIterator {
+            chunk_index(from), chunk_index(to),
+            index_in_chunk(from), index_in_chunk(to)
+        };
+    }
+
+    buffer<Chunk*, Allocator>    m_chunks;
+    isize_t                      m_size{};
+
+    void resize_uninit_inner(isize_t new_size)
+    {
+        ASL_ASSERT(new_size >= 0);
+
+        if constexpr (!trivially_destructible<T>)
+        {
+            const isize_t old_size = size();
+            if (new_size < old_size)
+            {
+                for (PerChunkIterator it = make_index_iterator(new_size, old_size - 1);
+                    it.has_more();
+                    it.advance())
+                {
+                    auto span = it.make_span(*m_chunks[it.chunk()]);
+                    for (auto& el: span)
+                    {
+                        el.destroy_unsafe();
+                    }
+                }
+            }
+        }
+
+        reserve_capacity(new_size);
+        m_size = new_size;
+    }
+
+    template<typename... Args>
+    void resize_construct(isize_t new_size, Args&&... args)
+        requires constructible_from<T, Args&&...>
+    {
+        const isize_t old_size = m_size;
+        resize_uninit_inner(new_size);
+
+        if (new_size > old_size)
+        {
+            for (PerChunkIterator it = make_index_iterator(old_size, new_size - 1);
+                it.has_more();
+                it.advance())
+            {
+                auto span = it.make_span(*m_chunks[it.chunk()]);
+                for (auto& uninit: span)
+                {
+                    uninit.construct_unsafe(std::forward<Args>(args)...);
+                }
+            }
+        }
+    }
+
+    void copy_from(const chunked_buffer& other)
+        requires copyable<T>
+    {
+        const isize_t this_size = size();
+        isize_t to_copy_assign = asl::min(other.size(), this_size);
+
+        resize_uninit_inner(other.size());
+
+        for (PerChunkIterator it = make_index_iterator(0, to_copy_assign - 1);
+            it.has_more();
+            it.advance())
+        {
+            auto to_span = it.make_span(*m_chunks[it.chunk()]);
+            auto from_span = it.make_span(*other.m_chunks[it.chunk()]);
+
+            copy_assign_n(
+                reinterpret_cast<T*>(to_span.data()), // NOLINT(*-reinterpret-cast)
+                reinterpret_cast<const T*>(from_span.data()), // NOLINT(*-reinterpret-cast)
+                to_span.size());
+        }
+
+        if (other.size() > this_size)
+        {
+            for (PerChunkIterator it = make_index_iterator(to_copy_assign, other.size() - 1);
+                it.has_more();
+                it.advance())
+            {
+                auto to_span = it.make_span(*m_chunks[it.chunk()]);
+                auto from_span = it.make_span(*other.m_chunks[it.chunk()]);
+
+                copy_uninit_n(
+                    reinterpret_cast<T*>(to_span.data()), // NOLINT(*-reinterpret-cast)
+                    reinterpret_cast<const T*>(from_span.data()), // NOLINT(*-reinterpret-cast)
+                    to_span.size());
+            }
+        }
+
+        ASL_ASSERT(size() == other.size());
+    }
+
+public:
+    constexpr chunked_buffer()
+        requires default_constructible<Allocator>
+        = default;
+
+    explicit constexpr chunked_buffer(Allocator allocator)
+        : m_chunks{std::move(allocator)}
+    {}
+
+    constexpr chunked_buffer(const chunked_buffer& other)
+        requires copyable<T> && copy_constructible<Allocator>
+        : m_chunks{other.m_chunks.allocator_copy()}
+    {
+        copy_from(other);
+    }
+
+    constexpr chunked_buffer(chunked_buffer&& other)
+        : m_chunks{std::move(other.m_chunks)}
+        , m_size{asl::exchange(other.m_size, 0)}
+    {
+        ASL_ASSERT(other.m_chunks.size() == 0);
+    }
+
+    constexpr chunked_buffer& operator=(const chunked_buffer& other)
+        requires copyable<T>
+    {
+        if (&other == this) { return *this; }
+        copy_from(other);
+        return *this;
+    }
+
+    constexpr chunked_buffer& operator=(chunked_buffer&& other)
+    {
+        if (&other == this) { return *this; }
+        destroy();
+        m_chunks = std::move(other.m_chunks);
+        m_size = asl::exchange(other.m_size, 0);
+        ASL_ASSERT(other.m_chunks.size() == 0);
+        return *this;
+    }
+
+    ~chunked_buffer()
+    {
+        destroy();
+    }
+
+    void clear()
+    {
+        if constexpr (trivially_destructible<T>)
+        {
+            m_size = 0;
+        }
+        else if (m_size > 0)
+        {
+            resize_uninit_inner(0);
+            ASL_ASSERT(m_size == 0);
+        }
+    }
+
+    void destroy()
+    {
+        clear();
+        ASL_ASSERT(size() == 0);
+
+        for (Chunk* chunk:  m_chunks)
+        {
+            alloc_delete(m_chunks.allocator(), chunk);
+        }
+
+        m_chunks.destroy();
+    }
+
+    [[nodiscard]] constexpr isize_t size() const { return m_size; }
+
+    [[nodiscard]] constexpr bool is_empty() const { return size() == 0; }
+
+    [[nodiscard]] constexpr isize_t capacity() const
+    {
+        return m_chunks.size() * kChunkSize;
+    }
+
+    constexpr auto&& operator[](this auto&& self, isize_t i)
+    {
+        ASL_ASSERT(i >= 0 && i < self.m_size);
+        return std::forward_like<decltype(self)>(
+            (*std::forward<decltype(self)>(self).m_chunks[chunk_index(i)])
+                [index_in_chunk(i)].as_init_unsafe()
+        );
+    }
+
+    constexpr T& push(auto&&... args)
+        requires constructible_from<T, decltype(args)&&...>
+    {
+        const isize_t chunk = chunk_index(m_size);
+        const isize_t in_chunk = index_in_chunk(m_size);
+
+        if (m_size == capacity())
+        {
+            resize_uninit_inner(m_size + 1);
+        }
+        else
+        {
+            m_size += 1;
+        }
+
+        void* uninit = &(*m_chunks[chunk])[in_chunk];
+        return *construct_at<T>(uninit, std::forward<decltype(args)>(args)...);
+    }
+
+    void reserve_capacity(isize_t new_capacity)
+    {
+        new_capacity = round_up_pow2(new_capacity, kChunkSize);
+        if (new_capacity <= capacity()) { return; }
+
+        const isize_t required_chunks = new_capacity / kChunkSize;
+        const isize_t additional_chunks = required_chunks - m_chunks.size();
+        ASL_ASSERT(additional_chunks > 0);
+
+        m_chunks.reserve_capacity(required_chunks);
+        for (isize_t i = 0; i < additional_chunks; ++i)
+        {
+            // @Todo(C++26) _unsafe shouldn't be needed with trivial unions
+            auto* chunk = alloc_uninit_unsafe<Chunk>(m_chunks.allocator());
+            m_chunks.push(chunk);
+        }
+    }
+
+    void resize(isize_t new_size)
+        requires default_constructible<T>
+    {
+        if constexpr (trivially_default_constructible<T>)
+        {
+            resize_zero(new_size);
+        }
+        else
+        {
+            resize_construct(new_size);
+        }
+    }
+
+    void resize(isize_t new_size, const T& value)
+        requires copy_constructible<T>
+    {
+        resize_construct(new_size, value);
+    }
+
+    void resize_zero(isize_t new_size)
+        requires trivially_default_constructible<T>
+    {
+        const isize_t old_size = m_size;
+        resize_uninit_inner(new_size);
+
+        if (new_size > old_size)
+        {
+            for (PerChunkIterator it = make_index_iterator(old_size, new_size - 1);
+                it.has_more();
+                it.advance())
+            {
+                auto span = it.make_span(*m_chunks[it.chunk()]);
+                asl::memzero(span.data(), span.size_bytes());
+            }
+        }
+    }
+
+    void resize_uninit(isize_t new_size)
+        requires trivially_default_constructible<T>
+    {
+        resize_uninit_inner(new_size);
+    }
+
+    void pop()
+    {
+        ASL_ASSERT(size() > 0);
+        resize_uninit_inner(size() - 1);
+    }
+
+    template<typename Chunk>
+    class generic_iterator
+    {
+        isize_t     m_index;
+        span<Chunk> m_chunks;
+
+    public:
+        constexpr generic_iterator(isize_t index, span<Chunk> chunks)
+            : m_index{index}
+            , m_chunks{chunks}
+        {}
+
+        constexpr generic_iterator& operator++()
+        {
+            m_index += 1;
+            return *this;
+        }
+
+        constexpr generic_iterator operator++(int)
+        {
+            auto tmp = *this;
+            m_index += 1;
+            return tmp;
+        }
+
+        constexpr bool operator==(this generic_iterator self, generic_iterator other)
+        {
+            ASL_ASSERT(self.m_chunks.data() == other.m_chunks.data());
+            return self.m_index == other.m_index;
+        }
+
+        constexpr auto& operator*(this generic_iterator self)
+        {
+            ASL_ASSERT(self.m_index >= 0);
+            return (*self.m_chunks[chunk_index(self.m_index)])[index_in_chunk(self.m_index)].as_init_unsafe();
+        }
+
+        constexpr auto* operator->(this generic_iterator self)
+        {
+            return &*self;
+        }
+    };
+
+    using iterator       = generic_iterator<Chunk*>;
+    using const_iterator = generic_iterator<const Chunk* const>;
+
+    constexpr iterator begin() { return iterator{0, m_chunks}; }
+    constexpr iterator end()   { return iterator{m_size, m_chunks}; }
+
+    constexpr const_iterator begin() const
+    {
+        return const_iterator{0, {m_chunks.data(), m_chunks.size()}};
+    }
+
+    constexpr const_iterator end() const
+    {
+        return const_iterator{m_size, {m_chunks.data(), m_chunks.size()}};
+    }
+};
+
+} // namespace asl
+
--- a/asl/containers/chunked_buffer_tests.cpp
+++ b/asl/containers/chunked_buffer_tests.cpp
@ -0,0 +1,377 @@
+// Copyright 2025 Steven Le Rouzic
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#include "asl/testing/testing.hpp"
+#include "asl/tests/types.hpp"
+#include "asl/tests/counting_allocator.hpp"
+#include "asl/containers/chunked_buffer.hpp"
+
+static_assert(asl::moveable<asl::chunked_buffer<int, 8>>);
+static_assert(asl::moveable<asl::chunked_buffer<Copyable, 8>>);
+static_assert(asl::moveable<asl::chunked_buffer<MoveableOnly, 8>>);
+static_assert(asl::moveable<asl::chunked_buffer<Pinned, 8>>);
+
+static_assert(asl::copyable<asl::chunked_buffer<int, 8>>);
+static_assert(asl::copyable<asl::chunked_buffer<Copyable, 8>>);
+static_assert(!asl::copyable<asl::chunked_buffer<MoveableOnly, 8>>);
+static_assert(!asl::copyable<asl::chunked_buffer<Pinned, 8>>);
+
+ASL_TEST(reserve)
+{
+    asl::chunked_buffer<int, 16> b;
+    ASL_TEST_EXPECT(b.capacity() == 0);
+    ASL_TEST_EXPECT(b.size() == 0);
+
+    b.reserve_capacity(1);
+    ASL_TEST_EXPECT(b.capacity() == 16);
+    ASL_TEST_EXPECT(b.size() == 0);
+
+    b.reserve_capacity(5);
+    ASL_TEST_EXPECT(b.capacity() == 16);
+    ASL_TEST_EXPECT(b.size() == 0);
+
+    b.reserve_capacity(16);
+    ASL_TEST_EXPECT(b.capacity() == 16);
+    ASL_TEST_EXPECT(b.size() == 0);
+
+    b.reserve_capacity(35);
+    ASL_TEST_EXPECT(b.capacity() == 48);
+    ASL_TEST_EXPECT(b.size() == 0);
+
+    b.reserve_capacity(12);
+    ASL_TEST_EXPECT(b.capacity() == 48);
+    ASL_TEST_EXPECT(b.size() == 0);
+}
+
+ASL_TEST(resize_uninit)
+{
+    asl::chunked_buffer<int, 16> b;
+    ASL_TEST_EXPECT(b.capacity() == 0);
+    ASL_TEST_EXPECT(b.size() == 0);
+
+    b.resize_uninit(1);
+    ASL_TEST_EXPECT(b.capacity() == 16);
+    ASL_TEST_EXPECT(b.size() == 1);
+
+    b.resize_uninit(5);
+    ASL_TEST_EXPECT(b.capacity() == 16);
+    ASL_TEST_EXPECT(b.size() == 5);
+
+    b.resize_uninit(16);
+    ASL_TEST_EXPECT(b.capacity() == 16);
+    ASL_TEST_EXPECT(b.size() == 16);
+
+    b.resize_uninit(35);
+    ASL_TEST_EXPECT(b.capacity() == 48);
+    ASL_TEST_EXPECT(b.size() == 35);
+
+    b.resize_uninit(12);
+    ASL_TEST_EXPECT(b.capacity() == 48);
+    ASL_TEST_EXPECT(b.size() == 12);
+}
+
+ASL_TEST(resize_zero)
+{
+    asl::chunked_buffer<int, 4> b;
+    ASL_TEST_EXPECT(b.capacity() == 0);
+    ASL_TEST_EXPECT(b.size() == 0);
+
+    b.resize_zero(2);
+    for (isize_t i = 0; i < 2; ++i)
+    {
+        ASL_TEST_EXPECT(b[i] == 0);
+    }
+
+    b.resize_zero(18);
+    for (isize_t i = 0; i < 18; ++i)
+    {
+        ASL_TEST_EXPECT(b[i] == 0);
+    }
+}
+
+ASL_TEST(resize)
+{
+    asl::chunked_buffer<int, 4> b;
+    ASL_TEST_EXPECT(b.capacity() == 0);
+    ASL_TEST_EXPECT(b.size() == 0);
+
+    b.resize(10);
+    for (isize_t i = 0; i < 10; ++i)
+    {
+        ASL_TEST_EXPECT(b[i] == 0);
+    }
+
+    b.resize(20, 8);
+    for (isize_t i = 0; i < 10; ++i)
+    {
+        ASL_TEST_EXPECT(b[i] == 0);
+    }
+
+    for (isize_t i = 10; i < 20; ++i)
+    {
+        ASL_TEST_EXPECT(b[i] == 8);
+    }
+}
+
+ASL_TEST(push)
+{
+    asl::chunked_buffer<int, 4> b;
+
+    for (int i = 0; i < 100; ++i)
+    {
+        b.push(i);
+    }
+
+    for (int i = 0; i < 100; ++i)
+    {
+        ASL_TEST_EXPECT(b[i] == i);
+    }
+
+    b.resize(1000);
+    for (int i = 0; i < 100; ++i)
+    {
+        ASL_TEST_EXPECT(b[i] == i);
+    }
+}
+
+ASL_TEST(pop)
+{
+    asl::chunked_buffer<int, 2> b;
+
+    for (int i = 0; i < 8; ++i)
+    {
+        b.push(i);
+    }
+    ASL_TEST_EXPECT(b.size() == 8);
+
+    b.pop();
+    ASL_TEST_EXPECT(b.size() == 7);
+    for (int i = 0; i < 7; ++i)
+    {
+        ASL_TEST_EXPECT(b[i] == i);
+    }
+}
+
+ASL_TEST(pop_destruct)
+{
+    bool d[3]{};
+    asl::chunked_buffer<DestructorObserver, 16> b;
+
+    b.push(&d[0]);
+    b.push(&d[1]);
+    b.push(&d[2]);
+
+    ASL_TEST_EXPECT(!d[0]);
+    ASL_TEST_EXPECT(!d[1]);
+    ASL_TEST_EXPECT(!d[2]);
+
+    b.pop();
+    ASL_TEST_EXPECT(!d[0]);
+    ASL_TEST_EXPECT(!d[1]);
+    ASL_TEST_EXPECT(d[2]);
+
+    b.pop();
+    ASL_TEST_EXPECT(!d[0]);
+    ASL_TEST_EXPECT(d[1]);
+    ASL_TEST_EXPECT(d[2]);
+}
+
+ASL_TEST(clear_destroy)
+{
+    bool destroyed[5]{};
+    asl::chunked_buffer<DestructorObserver, 2> buf;
+
+    for (bool& d: destroyed)
+    {
+        buf.push(&d); // NOLINT
+    }
+
+    for (const bool d: destroyed)
+    {
+        ASL_TEST_EXPECT(!d);
+    }
+
+    buf.clear();
+
+    for (const bool d: destroyed)
+    {
+        ASL_TEST_EXPECT(d);
+    }
+}
+
+ASL_TEST(alloc_count) // NOLINT
+{
+    CountingAllocator::Stats stats;
+    asl::chunked_buffer<int, 4, CountingAllocator> buf{CountingAllocator{&stats}};
+
+    ASL_TEST_EXPECT(stats.alive_bytes == 0);
+    ASL_TEST_EXPECT(stats.alloc_count == 0);
+    ASL_TEST_EXPECT(stats.dealloc_count == 0);
+    ASL_TEST_EXPECT(stats.any_alloc_count() == 0);
+
+    buf.push(1);
+    ASL_TEST_EXPECT(stats.alive_bytes > 0);
+    ASL_TEST_EXPECT(stats.dealloc_count == 0);
+    ASL_TEST_EXPECT(stats.any_alloc_count() == 1);
+
+    buf.push(2);
+    buf.push(3);
+    buf.push(4);
+    ASL_TEST_EXPECT(stats.alive_bytes > 0);
+    ASL_TEST_EXPECT(stats.dealloc_count == 0);
+    ASL_TEST_EXPECT(stats.any_alloc_count() == 1);
+
+    buf.push(5);
+    buf.push(6);
+    ASL_TEST_EXPECT(stats.alive_bytes > 0);
+    ASL_TEST_EXPECT(stats.dealloc_count == 0);
+    ASL_TEST_EXPECT(stats.any_alloc_count() == 2);
+
+    buf.resize(8, 8);
+    ASL_TEST_EXPECT(stats.alive_bytes > 0);
+    ASL_TEST_EXPECT(stats.dealloc_count == 0);
+    ASL_TEST_EXPECT(stats.any_alloc_count() == 2);
+
+    buf.resize(32, 8);
+    ASL_TEST_EXPECT(stats.alive_bytes > 0);
+    ASL_TEST_EXPECT(stats.dealloc_count == 0);
+    ASL_TEST_EXPECT(stats.any_alloc_count() == 9);
+
+    buf.resize(16, 0);
+    ASL_TEST_EXPECT(stats.alive_bytes > 0);
+    ASL_TEST_EXPECT(stats.dealloc_count == 0);
+    ASL_TEST_EXPECT(stats.any_alloc_count() == 9);
+
+    buf.clear();
+    ASL_TEST_EXPECT(stats.alive_bytes > 0);
+    ASL_TEST_EXPECT(stats.dealloc_count == 0);
+    ASL_TEST_EXPECT(stats.any_alloc_count() == 9);
+
+    buf.destroy();
+    ASL_TEST_EXPECT(stats.alive_bytes == 0);
+    ASL_TEST_EXPECT(stats.dealloc_count == 9);
+    ASL_TEST_EXPECT(stats.any_alloc_count() == 9);
+}
+
+ASL_TEST(move)
+{
+    bool destroyed[5]{};
+
+    {
+        asl::chunked_buffer<DestructorObserver, 2> buf;
+
+        for (bool& d: destroyed)
+        {
+            buf.push(&d); // NOLINT
+        }
+
+        for (const bool d: destroyed)
+        {
+            ASL_TEST_EXPECT(!d);
+        }
+
+        asl::chunked_buffer<DestructorObserver, 2> buf2 = std::move(buf);
+
+        for (const bool d: destroyed)
+        {
+            ASL_TEST_EXPECT(!d);
+        }
+
+        buf = std::move(buf2);
+        buf2.destroy();
+
+        for (const bool d: destroyed)
+        {
+            ASL_TEST_EXPECT(!d);
+        }
+    }
+
+    for (const bool d: destroyed)
+    {
+        ASL_TEST_EXPECT(d);
+    }
+}
+
+ASL_TEST(copy) // NOLINT
+{
+    asl::chunked_buffer<int, 4> buf;
+    for (int i = 0; i < 10; ++i) { buf.push(i); }
+
+    asl::chunked_buffer<int, 4> buf2 = buf;
+
+    ASL_TEST_EXPECT(buf.size() == 10);
+    ASL_TEST_EXPECT(buf2.size() == 10);
+    for (int i = 0; i < 10; ++i)
+    {
+        ASL_TEST_EXPECT(buf[i] == i);
+        ASL_TEST_EXPECT(buf2[i] == i);
+    }
+
+    buf2.resize(5);
+    buf = buf2;
+
+    ASL_TEST_EXPECT(buf.size() == 5);
+    ASL_TEST_EXPECT(buf2.size() == 5);
+    for (int i = 0; i < 5; ++i)
+    {
+        ASL_TEST_EXPECT(buf[i] == i);
+        ASL_TEST_EXPECT(buf2[i] == i);
+    }
+
+    buf.clear();
+    buf.resize(80, 12);
+    buf2 = buf;
+    ASL_TEST_EXPECT(buf.size() == 80);
+    ASL_TEST_EXPECT(buf2.size() == 80);
+    for (int i = 0; i < 80; ++i)
+    {
+        ASL_TEST_EXPECT(buf[i] == 12);
+        ASL_TEST_EXPECT(buf2[i] == 12);
+    }
+}
+
+ASL_TEST(iterator)
+{
+    asl::chunked_buffer<int, 4> buf;
+    for (int i = 0; i < 30; ++i) { buf.push(100 + i); }
+
+    auto it = buf.begin();
+    auto end = buf.end();
+    for (int i = 0; i < 30; ++i)
+    {
+        ASL_TEST_ASSERT(it != end);
+        ASL_TEST_EXPECT(*it == 100 + i);
+        it++;
+    }
+    ASL_TEST_EXPECT(it == end);
+
+    static_assert(asl::same_as<decltype(*it), int&>);
+
+    asl::chunked_buffer<int, 8> buf2;
+    ASL_TEST_EXPECT(buf2.begin() == buf2.end());
+}
+
+ASL_TEST(const_iterator)
+{
+    asl::chunked_buffer<int, 4> buf_value;
+    for (int i = 0; i < 30; ++i) { buf_value.push(100 + i); }
+
+    const auto& buf = buf_value;
+
+    auto it = buf.begin();
+    auto end = buf.end();
+    for (int i = 0; i < 30; ++i)
+    {
+        ASL_TEST_ASSERT(it != end);
+        ASL_TEST_EXPECT(*it == 100 + i);
+        ++it;
+    }
+    ASL_TEST_EXPECT(it == end);
+
+    static_assert(asl::same_as<decltype(*it), const int&>);
+
+    asl::chunked_buffer<int, 8> buf2;
+    ASL_TEST_EXPECT(buf2.begin() == buf2.end());
+}
+
--- a/asl/containers/hash_map.hpp
+++ b/asl/containers/hash_map.hpp
@ -147,7 +147,7 @@ public:
    auto get(this auto&& self, const U& value)
        requires key_hasher<KeyHasher, U> && key_comparator<KeyComparator, K, U>
    {
-        using return_type = un_ref_t<copy_cref_t<decltype(self), V>>*;
+        using return_type = copy_const_t<un_ref_t<decltype(self)>, V>*;
        isize_t index = self.find_slot_lookup(value);
        if (index >= 0)
        {
--- a/asl/containers/hash_set.hpp
+++ b/asl/containers/hash_set.hpp
@ -7,6 +7,8 @@
 #include "asl/base/annotations.hpp"
 #include "asl/base/utility.hpp"
 #include "asl/base/meta.hpp"
+#include "asl/base/bit.hpp"
+#include "asl/base/numeric.hpp"
 #include "asl/memory/allocator.hpp"
 #include "asl/memory/memory.hpp"
 #include "asl/types/maybe_uninit.hpp"
@ -83,7 +85,7 @@ protected:
        ASL_ASSERT(size > 0);
        return max<isize_t>(
            kMinCapacity,
-            static_cast<isize_t>(round_up_pow2((static_cast<uint64_t>(size) * 4 + 2) / 3)));
+            static_cast<isize_t>(bit_ceil((static_cast<uint64_t>(size) * 4 + 2) / 3)));
    }

    static void insert_inner(
--- a/asl/containers/intrusive_list.hpp
+++ b/asl/containers/intrusive_list.hpp
@ -82,13 +82,13 @@ public:

    constexpr auto front(this auto&& self)
    {
-        using return_type = un_ref_t<copy_cref_t<decltype(self), T>>*;
+        using return_type = copy_const_t<un_ref_t<decltype(self)>, T>*;
        return return_type{ self.m_head };
    }

    constexpr auto back(this auto&& self)
    {
-        using return_type = un_ref_t<copy_cref_t<decltype(self), T>>*;
+        using return_type = copy_const_t<un_ref_t<decltype(self)>, T>*;
        return return_type{ self.m_head != nullptr ? self.m_head->m_prev : nullptr };
    }

--- a/asl/formatting/format.hpp
+++ b/asl/formatting/format.hpp
@ -5,6 +5,7 @@
 #pragma once

 #include "asl/base/integers.hpp"
+#include "asl/base/float.hpp"
 #include "asl/base/meta.hpp"
 #include "asl/io/writer.hpp"
 #include "asl/types/span.hpp"
@ -93,8 +94,8 @@ inline void AslFormat(Formatter& f, string_view sv)
    f.write(sv);
 }

-void AslFormat(Formatter& f, float);
-void AslFormat(Formatter& f, double);
+void AslFormat(Formatter& f, float32_t);
+void AslFormat(Formatter& f, float64_t);

 void AslFormat(Formatter& f, bool);

--- a/asl/formatting/format_float.cpp
+++ b/asl/formatting/format_float.cpp
@ -4,10 +4,14 @@

 #include "asl/formatting/format.hpp"
 #include "asl/base/float.hpp"
+#include "asl/base/numeric.hpp"

+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Weverything"
 #define JKJ_STD_REPLACEMENT_NAMESPACE_DEFINED 0
 #define JKJ_STATIC_DATA_SECTION_DEFINED 0
 #include <dragonbox.h>
+#pragma clang diagnostic pop

 static constexpr isize_t kZeroCount = 100;
 static constexpr char kZeros[kZeroCount] = {
@ -23,12 +27,12 @@ static constexpr char kZeros[kZeroCount] = {
    '0', '0', '0', '0', '0', '0', '0', '0', '0', '0',
 };

-static constexpr bool is_zero(float x)
+static constexpr bool is_zero(float32_t x)
 {
    return (asl::bit_cast<uint32_t>(x) & 0x7fff'ffffU) == 0;
 }

-static constexpr bool is_zero(double x)
+static constexpr bool is_zero(float64_t x)
 {
    return (asl::bit_cast<uint64_t>(x) & 0x7fff'ffff'ffff'ffffULL) == 0;
 }
@ -101,12 +105,12 @@ static void format_float(asl::Formatter& f, T value)
    }
 }

-void asl::AslFormat(Formatter& f, float value)
+void asl::AslFormat(Formatter& f, float32_t value)
 {
    format_float(f, value);
 }

-void asl::AslFormat(Formatter& f, double value)
+void asl::AslFormat(Formatter& f, float64_t value)
 {
    format_float(f, value);
 }
--- a/asl/formatting/format_tests.cpp
+++ b/asl/formatting/format_tests.cpp
@ -79,7 +79,7 @@ ASL_TEST(format_floats)
    s = asl::format_to_string("{}", 123e-8);
    ASL_TEST_EXPECT(s == "0.00000123"_sv);

-    s = asl::format_to_string("{} {}", asl::infinity<float>(), -asl::infinity<double>());
+    s = asl::format_to_string("{} {}", asl::infinity<float32_t>(), -asl::infinity<float64_t>());
    ASL_TEST_EXPECT(s == "Infinity -Infinity"_sv);

    s = asl::format_to_string("{}", asl::nan<float>());
--- a/asl/handle_pool/BUILD.bazel
+++ b/asl/handle_pool/BUILD.bazel
@ -0,0 +1,81 @@
+# Copyright 2025 Steven Le Rouzic
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+package(
+    default_applicable_licenses = ["//:license"],
+)
+
+cc_library(
+    name = "index_pool",
+    hdrs = [
+        "index_pool.hpp",
+    ],
+    deps = [
+        "//asl/memory",
+        "//asl/memory:allocator",
+        "//asl/base",
+        "//asl/containers:chunked_buffer",
+        "//asl/types:option",
+    ],
+    visibility = ["//visibility:public"],
+)
+
+cc_library(
+    name = "dense_handle_pool",
+    hdrs = [
+        "dense_handle_pool.hpp",
+    ],
+    deps = [
+        ":index_pool",
+    ],
+    visibility = ["//visibility:public"],
+)
+
+cc_library(
+    name = "sparse_handle_pool",
+    hdrs = [
+        "sparse_handle_pool.hpp",
+    ],
+    deps = [
+        ":index_pool",
+    ],
+    visibility = ["//visibility:public"],
+)
+
+cc_test(
+    name = "index_pool_tests",
+    srcs = [
+        "index_pool_tests.cpp",
+    ],
+    deps = [
+        ":index_pool",
+        "//asl/hashing",
+        "//asl/tests:utils",
+        "//asl/testing",
+    ],
+)
+
+cc_test(
+    name = "dense_handle_pool_tests",
+    srcs = [
+        "dense_handle_pool_tests.cpp",
+    ],
+    deps = [
+        ":dense_handle_pool",
+        "//asl/tests:utils",
+        "//asl/testing",
+    ],
+)
+
+cc_test(
+    name = "sparse_handle_pool_tests",
+    srcs = [
+        "sparse_handle_pool_tests.cpp",
+    ],
+    deps = [
+        ":sparse_handle_pool",
+        "//asl/tests:utils",
+        "//asl/testing",
+    ],
+)
--- a/asl/handle_pool/dense_handle_pool.hpp
+++ b/asl/handle_pool/dense_handle_pool.hpp
@ -0,0 +1,162 @@
+// Copyright 2025 Steven Le Rouzic
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#pragma once
+
+#include "asl/handle_pool/index_pool.hpp"
+#include "asl/memory/allocator.hpp"
+#include "asl/containers/chunked_buffer.hpp"
+
+
+namespace asl
+{
+
+// @Todo If we want the allocator to be non-copyable, we could
+// introduce a reference allocator type that is copyable, and store
+// the "main" allocator in the pool.
+
+template<
+    is_object T,
+    int kIndexBits,
+    int kGenBits,
+    typename UserType = empty,
+    int kUserBits = 0,
+    isize_t kChunkSize = 32,
+    allocator Allocator = DefaultAllocator>
+requires moveable<T> && copyable<Allocator>
+class DenseHandlePool
+{
+    using ThisIndexPool = IndexPool<kIndexBits, kGenBits, UserType, kUserBits, isize_t, Allocator>;
+
+    struct Slot
+    {
+        ThisIndexPool::handle h;
+        T obj;
+
+        template<typename... Args>
+        explicit Slot(ThisIndexPool::handle h_, Args&&... args)
+            : h{h_}
+            , obj(std::forward<Args>(args)...)
+        {}
+    };
+
+    using Buffer = chunked_buffer<Slot, kChunkSize, Allocator>;
+
+    ThisIndexPool m_index_pool{};
+    Buffer        m_buffer{};
+
+    using config = ThisIndexPool::handle::config;
+
+    template<typename... Args>
+    isize_t push(Args&&... args)
+        requires constructible_from<T, Args&&...>
+    {
+        m_buffer.push(typename ThisIndexPool::handle{}, std::forward<Args>(args)...);
+        return m_buffer.size() - 1;
+    }
+
+public:
+    using handle = ThisIndexPool::handle;
+
+    DenseHandlePool() requires default_constructible<Allocator> = default;
+
+    explicit DenseHandlePool(const Allocator& allocator)
+        : m_index_pool(allocator)
+        , m_buffer(allocator)
+    {}
+
+    ASL_DELETE_COPY(DenseHandlePool);
+    ASL_DEFAULT_MOVE(DenseHandlePool);
+    ~DenseHandlePool() = default;
+
+    [[nodiscard]] bool is_full() const
+    {
+        return m_index_pool.is_full();
+    }
+
+    bool is_valid(handle h) const
+    {
+        return m_index_pool.is_valid(h);
+    }
+
+    template<typename... Args>
+    option<handle> acquire(config::UserType user, Args&&... args)
+        requires config::kHasUser && constructible_from<T, Args&&...>
+    {
+        if (is_full()) { return nullopt; }
+        const isize_t obj_index = push(std::forward<Args>(args)...);
+        const auto handle = m_index_pool.acquire_ensure(user, obj_index);
+        m_buffer[obj_index].h = handle;
+        return handle;
+    }
+
+    template<typename... Args>
+    option<handle> acquire(Args&&... args)
+        requires (!config::kHasUser) && constructible_from<T, Args&&...>
+    {
+        if (is_full()) { return nullopt; }
+        const isize_t obj_index = push(std::forward<Args>(args)...);
+        const auto handle = m_index_pool.acquire_ensure(obj_index);
+        m_buffer[obj_index].h = handle;
+        return handle;
+    }
+
+    template<typename... Args>
+    handle acquire_ensure(config::UserType user, Args&&... args)
+        requires config::kHasUser && constructible_from<T, Args&&...>
+    {
+        ASL_ASSERT_RELEASE(!is_full());
+        const isize_t obj_index = push(std::forward<Args>(args)...);
+        const auto handle = m_index_pool.acquire_ensure(user, obj_index);
+        m_buffer[obj_index].h = handle;
+        return handle;
+    }
+
+    template<typename... Args>
+    handle acquire_ensure(Args&&... args)
+        requires (!config::kHasUser) && constructible_from<T, Args&&...>
+    {
+        ASL_ASSERT_RELEASE(!is_full());
+        const isize_t obj_index = push(std::forward<Args>(args)...);
+        const auto handle = m_index_pool.acquire_ensure(obj_index);
+        m_buffer[obj_index].h = handle;
+        return handle;
+    }
+
+    void release(handle to_release_handle)
+    {
+        if (!is_valid(to_release_handle)) { return; }
+
+        const auto to_release_index = *m_index_pool.get_payload(to_release_handle);
+        if (to_release_index < m_buffer.size() - 1)
+        {
+            const auto to_swap_index = m_buffer.size() - 1;
+            const auto to_swap_handle = m_buffer[to_swap_index].h;
+
+            m_buffer[to_release_index] = std::move(m_buffer[to_swap_index]);
+            m_index_pool.exchange_payload(to_swap_handle, to_release_index);
+        }
+
+        m_buffer.pop();
+        m_index_pool.release(to_release_handle);
+    }
+
+    auto get(this auto&& self, handle h)
+        -> copy_const_t<un_ref_t<decltype(self)>, T>*
+    {
+        if (!self.is_valid(h)) { return nullptr; }
+        const auto index = *self.m_index_pool.get_payload(h);
+        return &self.m_buffer[index].obj;
+    }
+
+    auto get_ensure(this auto&& self, handle h)
+        -> copy_cref_t<decltype(self), T>
+    {
+        ASL_ASSERT_RELEASE(self.is_valid(h));
+        const auto index = *self.m_index_pool.get_payload(h);
+        return std::forward<decltype(self)>(self).m_buffer[index].obj;
+    }
+};
+
+} // namespace asl
--- a/asl/handle_pool/dense_handle_pool_tests.cpp
+++ b/asl/handle_pool/dense_handle_pool_tests.cpp
@ -0,0 +1,117 @@
+// Copyright 2025 Steven Le Rouzic
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#include "asl/testing/testing.hpp"
+#include "asl/tests/types.hpp"
+#include "asl/handle_pool/dense_handle_pool.hpp"
+
+ASL_TEST(acquire_release) // NOLINT
+{
+    asl::DenseHandlePool<int, 1, 1> pool;
+
+    ASL_TEST_EXPECT(!pool.is_full());
+
+    const auto a = pool.acquire_ensure(6);
+    const auto b = pool.acquire_ensure(7);
+
+    ASL_TEST_EXPECT(pool.is_valid(a));
+    ASL_TEST_EXPECT(pool.is_valid(b));
+    ASL_TEST_EXPECT(pool.is_full());
+
+    ASL_TEST_EXPECT(pool.get_ensure(a) == 6);
+    ASL_TEST_EXPECT(pool.get_ensure(b) == 7);
+
+    pool.release(a);
+    ASL_TEST_EXPECT(!pool.is_valid(a));
+    ASL_TEST_EXPECT(pool.is_valid(b));
+    ASL_TEST_EXPECT(!pool.is_full());
+    ASL_TEST_EXPECT(pool.get(a) == nullptr);
+    ASL_TEST_EXPECT(*pool.get(b) == 7);
+
+    const auto c = pool.acquire_ensure(8);
+
+    ASL_TEST_EXPECT(!pool.is_valid(a));
+    ASL_TEST_EXPECT(pool.is_valid(b));
+    ASL_TEST_EXPECT(pool.is_valid(c));
+    ASL_TEST_EXPECT(pool.is_full());
+
+    ASL_TEST_EXPECT(*pool.get(b) == 7);
+    ASL_TEST_EXPECT(*pool.get(c) == 8);
+    ASL_TEST_EXPECT(pool.get(a) == nullptr);
+}
+
+ASL_TEST(element_destructor)
+{
+    asl::DenseHandlePool<DestructorObserver, 8, 8> pool;
+    bool d[3]{};
+
+    const auto d0 = pool.acquire_ensure(&d[0]);
+    const auto d1 = pool.acquire_ensure(&d[1]);
+    const auto d2 = pool.acquire_ensure(&d[2]);
+
+    ASL_TEST_EXPECT(!d[0]);
+    ASL_TEST_EXPECT(!d[1]);
+    ASL_TEST_EXPECT(!d[2]);
+
+    pool.release(d1);
+    ASL_TEST_EXPECT(!d[0]);
+    ASL_TEST_EXPECT(d[1]);
+    ASL_TEST_EXPECT(!d[2]);
+
+    pool.release(d0);
+    ASL_TEST_EXPECT(d[0]);
+    ASL_TEST_EXPECT(d[1]);
+    ASL_TEST_EXPECT(!d[2]);
+
+    pool.release(d2);
+    ASL_TEST_EXPECT(d[0]);
+    ASL_TEST_EXPECT(d[1]);
+    ASL_TEST_EXPECT(d[2]);
+}
+
+ASL_TEST(destructor)
+{
+    bool d[3]{};
+
+    {
+        asl::DenseHandlePool<DestructorObserver, 8, 8> pool;
+
+        pool.acquire_ensure(&d[0]);
+        const auto d1 = pool.acquire_ensure(&d[1]);
+        pool.acquire_ensure(&d[2]);
+
+        ASL_TEST_EXPECT(!d[0]);
+        ASL_TEST_EXPECT(!d[1]);
+        ASL_TEST_EXPECT(!d[2]);
+
+        pool.release(d1);
+        ASL_TEST_EXPECT(!d[0]);
+        ASL_TEST_EXPECT(d[1]);
+        ASL_TEST_EXPECT(!d[2]);
+    }
+
+    ASL_TEST_EXPECT(d[0]);
+    ASL_TEST_EXPECT(d[1]);
+    ASL_TEST_EXPECT(d[2]);
+}
+
+enum Flags : uint8_t
+{
+    kFlag1 = 1,
+    kFlag2 = 2,
+};
+
+ASL_TEST(user_type)
+{
+    asl::DenseHandlePool<int, 8, 8, Flags> pool;
+
+    auto a = pool.acquire_ensure(kFlag2, 22);
+    auto b = pool.acquire_ensure(kFlag1, 11);
+
+    ASL_TEST_EXPECT(pool.get_ensure(a) == 22);
+    ASL_TEST_EXPECT(pool.get_ensure(b) == 11);
+
+    ASL_TEST_EXPECT(a.user() == kFlag2);
+    ASL_TEST_EXPECT(b.user() == kFlag1);
+}
--- a/asl/handle_pool/index_pool.hpp
+++ b/asl/handle_pool/index_pool.hpp
@ -0,0 +1,378 @@
+// Copyright 2025 Steven Le Rouzic
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#include "asl/base/integers.hpp"
+#include "asl/base/meta.hpp"
+#include "asl/containers/chunked_buffer.hpp"
+#include "asl/memory/allocator.hpp"
+#include "asl/types/option.hpp"
+
+namespace asl
+{
+
+template<
+    int kIndexBits_,
+    int kGenBits_,
+    typename UserType_ = empty,
+    int kUserBits_ = 0
+>
+requires (kIndexBits_ > 0 && kGenBits_ > 0 && kUserBits_ >= 0)
+struct index_pool_config
+{
+    static constexpr bool kHasUser = !same_as<UserType_, empty>;
+
+    using UserType          = UserType_;
+    using PrimitiveUserType = smallest_unsigned_integer_type_for_width<size_of<UserType> * 8>;
+
+    static_assert(trivially_copy_constructible<UserType>);
+    static_assert(trivially_destructible<UserType>);
+    static_assert(size_of<UserType> == size_of<PrimitiveUserType>, "UserType should be of size 1, 2 or 4");
+
+    static constexpr int kUserBits = []() static -> int {
+        if constexpr (!kHasUser) { return 0; };
+        return kUserBits_ == 0 ? size_of<UserType> * 8 : kUserBits_;
+    }();
+
+    static_assert(kUserBits <= size_of<UserType> * 8);
+
+    static constexpr int kIndexBits = kIndexBits_;
+    static constexpr int kGenBits   = kGenBits_;
+
+    static_assert(kIndexBits + kGenBits + kUserBits <= 63);
+
+    using HandleType = smallest_unsigned_integer_type_for_width<kIndexBits + kGenBits + kUserBits + 1>;
+
+    static constexpr int        kGenShift  = kIndexBits;
+    static constexpr int        kUserShift = kIndexBits + kGenBits;
+
+    static constexpr HandleType kValidMask = HandleType{1} << (size_of<HandleType> * 8 - 1);
+    static constexpr HandleType kIndexMask = (HandleType{1} << kIndexBits) - 1;
+    static constexpr HandleType kGenMask   = ((HandleType{1} << kGenBits) - 1) << kGenShift;
+    static constexpr HandleType kUserMask  = ((HandleType{1} << kUserBits) - 1) << kUserShift;
+    static constexpr HandleType kNiche     = static_cast<HandleType>(~uint64_t{kValidMask});
+
+    static constexpr uint64_t   kMaxGen    = (uint64_t{1} << kGenBits) - 1;
+    static constexpr uint64_t   kMaxIndex  = (uint64_t{1} << kIndexBits) - 1;
+};
+
+template<
+    int kIndexBits_,
+    int kGenBits_,
+    typename UserType_ = empty,
+    int kUserBits_ = 0
+>
+class index_pool_handle
+{
+public:
+    using config = index_pool_config<kIndexBits_, kGenBits_, UserType_, kUserBits_>;
+
+private:
+    config::HandleType m_handle{};
+
+public:
+    constexpr index_pool_handle() = default;
+
+    constexpr explicit index_pool_handle(niche_t)
+        : m_handle{config::kNiche}
+    {}
+
+    constexpr index_pool_handle(uint64_t index, uint64_t gen)
+        requires (!config::kHasUser)
+        : m_handle{static_cast<config::HandleType>(
+            config::kValidMask |
+            (index & config::kIndexMask) |
+            ((gen << config::kGenShift) & config::kGenMask))}
+    {
+        ASL_ASSERT((index & uint64_t{config::kIndexMask}) == index);
+        ASL_ASSERT((gen & (uint64_t{config::kGenMask} >> config::kGenShift)) == gen);
+    }
+
+    constexpr index_pool_handle(uint64_t index, uint64_t gen, config::UserType user)
+        requires config::kHasUser
+        : m_handle{static_cast<config::HandleType>(
+            config::kValidMask |
+            (index & config::kIndexMask) |
+            ((gen << config::kGenShift) & config::kGenMask) |
+            ((static_cast<config::HandleType>(bit_cast<typename config::PrimitiveUserType>(user)) << config::kUserShift) & config::kUserMask))}
+    {
+        ASL_ASSERT((index & uint64_t{config::kIndexMask}) == index);
+        ASL_ASSERT((gen & (uint64_t{config::kGenMask} >> config::kGenShift)) == gen);
+        ASL_ASSERT((bit_cast<typename config::PrimitiveUserType>(user) & (uint64_t{config::kUserMask} >> config::kUserShift)) == bit_cast<typename config::PrimitiveUserType>(user));
+    }
+
+    constexpr bool is_null(this index_pool_handle self)
+    {
+        return !(self.m_handle & config::kValidMask);
+    }
+
+    constexpr uint64_t index(this index_pool_handle self)
+    {
+        return self.m_handle & config::kIndexMask;
+    }
+
+    constexpr uint64_t gen(this index_pool_handle self)
+    {
+        return (self.m_handle & config::kGenMask) >> config::kGenShift;
+    }
+
+    constexpr config::UserType user(this index_pool_handle self)
+    {
+        return bit_cast<typename config::UserType>(static_cast<config::PrimitiveUserType>(
+            ((self.m_handle & config::kUserMask) >> config::kUserShift)));
+    }
+
+    constexpr bool operator==(this index_pool_handle self, index_pool_handle other) = default;
+
+    constexpr bool operator==(this index_pool_handle self, niche_t)
+    {
+        return self.m_handle == config::kNiche;
+    }
+};
+
+template<
+    int kIndexBits_,
+    int kGenBits_,
+    typename UserType_,
+    int kUserBits_
+>
+struct is_uniquely_represented<index_pool_handle<kIndexBits_, kGenBits_, UserType_, kUserBits_>> : true_type {};
+
+template<
+    int kIndexBits_,
+    int kGenBits_,
+    typename UserType_ = empty,
+    int kUserBits_ = 0,
+    typename Payload = empty,
+    allocator Allocator = DefaultAllocator
+>
+class IndexPool
+{
+public:
+    using handle = index_pool_handle<kIndexBits_, kGenBits_, UserType_, kUserBits_>;
+
+private:
+    using config = handle::config;
+
+    using internal_handle = index_pool_handle<
+        kIndexBits_,
+        kGenBits_,
+        typename config::PrimitiveUserType,
+        kUserBits_>;
+
+    static constexpr bool kHasPayload = !same_as<Payload, empty>;
+
+    // @Todo Remove need for default constructible & trivially destructible for payload
+    // Use maybe_uninit for it
+
+    static_assert(default_constructible<Payload>);
+    static_assert(copy_constructible<Payload>);
+    static_assert(trivially_destructible<Payload>);
+
+    struct Slot
+    {
+        bool is_end_of_list : 1;
+        bool is_active      : 1;
+
+        internal_handle handle;
+
+        ASL_NO_UNIQUE_ADDRESS Payload payload;
+    };
+
+    chunked_buffer<Slot, 256, Allocator> m_slots;
+
+    // We only use the index, this is essentially the head of the linked
+    // list to the first available slot.
+    // Then the index of each slot points to the next available one.
+    internal_handle m_first_available;
+
+    void allocate_new_slot()
+    {
+        const auto new_index = static_cast<uint64_t>(m_slots.size());
+        if (new_index > config::kMaxIndex) { return; }
+
+        const internal_handle new_handle = internal_handle(new_index, 0, 0);
+
+        m_slots.push(Slot{
+            .is_end_of_list = true,
+            .is_active      = false,
+            .handle         = new_handle,
+            .payload        = Payload{}
+        });
+
+        m_first_available = new_handle;
+    }
+
+    option<internal_handle> acquire_handle(const Payload& payload)
+    {
+        if (m_first_available.is_null())
+        {
+            allocate_new_slot();
+        }
+
+        if (m_first_available.is_null())
+        {
+            return nullopt;
+        }
+
+        auto index = m_first_available.index();
+
+        Slot& slot = m_slots[static_cast<isize_t>(index)];
+        ASL_ASSERT(!slot.is_active);
+
+        m_first_available = slot.is_end_of_list ? internal_handle{} : slot.handle;
+
+        slot.is_active = true;
+        slot.payload   = payload;
+
+        return internal_handle(index, slot.handle.gen(), 0);
+    }
+
+    auto get_slot_if_valid(this auto&& self, handle h)
+        -> copy_const_t<decltype(self), Slot>*
+    {
+        if (h.is_null()) { return nullptr; }
+
+        auto index = static_cast<isize_t>(h.index());
+        if (index < 0 || index >= self.m_slots.size()) { return nullptr; }
+
+        auto& slot = self.m_slots[index];
+        if (!slot.is_active || slot.handle.gen() != h.gen())
+        {
+            return nullptr;
+        }
+
+        return &slot;
+    }
+
+public:
+    IndexPool() requires default_constructible<Allocator> = default;
+
+    explicit IndexPool(Allocator allocator) : m_slots{std::move(allocator)} {}
+
+    [[nodiscard]] bool is_full() const
+    {
+        return m_first_available.is_null()
+            && static_cast<uint64_t>(m_slots.size()) > config::kMaxIndex;
+    }
+
+    option<handle> acquire()
+        requires (!kHasPayload && !config::kHasUser)
+    {
+        return acquire_handle({}).transform([](internal_handle h)
+        {
+            return handle(h.index(), h.gen());
+        });
+    }
+
+    handle acquire_ensure()
+        requires (!kHasPayload && !config::kHasUser)
+    {
+        auto opt = acquire();
+        ASL_ASSERT_RELEASE(opt.has_value());
+        return opt.value();
+    }
+
+    option<handle> acquire(const Payload& payload)
+        requires (kHasPayload && !config::kHasUser)
+    {
+        return acquire_handle(payload).transform([](internal_handle h)
+        {
+            return handle(h.index(), h.gen());
+        });
+    }
+
+    handle acquire_ensure(const Payload& payload)
+        requires (kHasPayload && !config::kHasUser)
+    {
+        auto opt = acquire(payload);
+        ASL_ASSERT_RELEASE(opt.has_value());
+        return opt.value();
+    }
+
+    option<handle> acquire(config::UserType user)
+        requires (!kHasPayload && config::kHasUser)
+    {
+        return acquire_handle({}).transform([user](internal_handle h)
+        {
+            return handle(h.index(), h.gen(), user);
+        });
+    }
+
+    handle acquire_ensure(config::UserType user)
+        requires (!kHasPayload && config::kHasUser)
+    {
+        auto opt = acquire(user);
+        ASL_ASSERT_RELEASE(opt.has_value());
+        return opt.value();
+    }
+
+    option<handle> acquire(config::UserType user, const Payload& payload)
+        requires (kHasPayload && config::kHasUser)
+    {
+        return acquire_handle(payload).transform([user](internal_handle h)
+        {
+            return handle(h.index(), h.gen(), user);
+        });
+    }
+
+    handle acquire_ensure(config::UserType user, const Payload& payload)
+        requires (kHasPayload && config::kHasUser)
+    {
+        auto opt = acquire(user, payload);
+        ASL_ASSERT_RELEASE(opt.has_value());
+        return opt.value();
+    }
+
+    // @Todo Add a policy to abandon slots that reached max generation
+    void release(handle h)
+    {
+        if (Slot* slot = get_slot_if_valid(h); slot != nullptr)
+        {
+            const uint64_t next_gen = h.gen() == config::kMaxGen ? 0 : h.gen() + 1;
+
+            slot->is_active = false;
+
+            if (m_first_available.is_null())
+            {
+                slot->is_end_of_list = true;
+                slot->handle = internal_handle(h.index(), next_gen, 0);
+            }
+            else
+            {
+                slot->is_end_of_list = false;
+                slot->handle = internal_handle(m_first_available.index(), next_gen, 0);
+            }
+
+            m_first_available = internal_handle(h.index(), 0, 0);
+        }
+    }
+
+    bool is_valid(handle h) const
+    {
+        return get_slot_if_valid(h) != nullptr;
+    }
+
+    const Payload* get_payload(handle h) const
+        requires kHasPayload
+    {
+        if (const Slot* slot = get_slot_if_valid(h); slot != nullptr)
+        {
+            return &slot->payload;
+        }
+        return nullptr;
+    }
+
+    option<Payload> exchange_payload(handle h, Payload new_payload)
+        requires kHasPayload
+    {
+        if (Slot* slot = get_slot_if_valid(h); slot != nullptr)
+        {
+            return asl::exchange(slot->payload, new_payload);
+        }
+        return nullopt;
+    }
+};
+
+} // namespace asl
+
--- a/asl/handle_pool/index_pool_tests.cpp
+++ b/asl/handle_pool/index_pool_tests.cpp
@ -0,0 +1,348 @@
+// Copyright 2025 Steven Le Rouzic
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#include "asl/testing/testing.hpp"
+#include "asl/handle_pool/index_pool.hpp"
+#include "asl/hashing/hash.hpp"
+
+enum Flags: uint8_t {
+    kFlag0 = 0,
+    kFlag1 = 1,
+    kFlag2 = 2,
+};
+
+using Cfg1 = asl::index_pool_config<4, 3>;
+static_assert(!Cfg1::kHasUser);
+static_assert(Cfg1::kUserBits == 0);
+static_assert(asl::same_as<Cfg1::HandleType, uint8_t>);
+static_assert(Cfg1::kValidMask == uint8_t{0x80});
+static_assert(Cfg1::kIndexMask == uint8_t{0x0f});
+static_assert(Cfg1::kGenMask   == uint8_t{0x70});
+static_assert(Cfg1::kGenShift  == 4);
+static_assert(Cfg1::kMaxGen    == 7);
+static_assert(Cfg1::kMaxIndex  == 15);
+
+using Cfg2 = asl::index_pool_config<5, 5, Flags>;
+static_assert(Cfg2::kHasUser);
+static_assert(Cfg2::kUserBits == 8);
+static_assert(asl::same_as<Cfg2::PrimitiveUserType, uint8_t>);
+static_assert(asl::same_as<Cfg2::HandleType, uint32_t>);
+static_assert(Cfg2::kValidMask == uint32_t{0x8000'0000});
+static_assert(Cfg2::kIndexMask == uint32_t{0x0000'001f});
+static_assert(Cfg2::kGenMask   == uint32_t{0x0000'03e0});
+static_assert(Cfg2::kUserMask  == uint32_t{0x0003'fc00});
+static_assert(Cfg2::kGenShift  == 5);
+static_assert(Cfg2::kUserShift == 10);
+static_assert(Cfg2::kMaxGen    == 31);
+static_assert(Cfg2::kMaxIndex  == 31);
+
+using Cfg3 = asl::index_pool_config<5, 6, Flags, 4>;
+static_assert(Cfg3::kHasUser);
+static_assert(Cfg3::kUserBits == 4);
+static_assert(asl::same_as<Cfg3::PrimitiveUserType, uint8_t>);
+static_assert(asl::same_as<Cfg3::HandleType, uint16_t>);
+static_assert(Cfg3::kValidMask == uint16_t{0x8000});
+static_assert(Cfg3::kIndexMask == uint16_t{0x001f});
+static_assert(Cfg3::kGenMask   == uint16_t{0x07e0});
+static_assert(Cfg3::kUserMask  == uint16_t{0x7800});
+static_assert(Cfg3::kGenShift  == 5);
+static_assert(Cfg3::kUserShift == 11);
+static_assert(Cfg3::kMaxGen    == 63);
+static_assert(Cfg3::kMaxIndex  == 31);
+
+static_assert(asl::default_constructible<asl::index_pool_handle<5, 5, uint8_t>>);
+static_assert(asl::trivially_copy_constructible<asl::index_pool_handle<5, 5, uint8_t>>);
+static_assert(asl::trivially_move_constructible<asl::index_pool_handle<5, 5, uint8_t>>);
+static_assert(asl::trivially_copy_assignable<asl::index_pool_handle<5, 5, uint8_t>>);
+static_assert(asl::trivially_move_assignable<asl::index_pool_handle<5, 5, uint8_t>>);
+static_assert(asl::trivially_destructible<asl::index_pool_handle<5, 5, uint8_t>>);
+
+static_assert(asl::hashable<asl::index_pool_handle<5, 5, uint8_t>>);
+static_assert(asl::has_niche<asl::index_pool_handle<5, 5, uint8_t>>);
+
+ASL_TEST(default_is_invalid)
+{
+    const asl::index_pool_handle<5, 5, uint8_t> idx;
+    ASL_TEST_EXPECT(idx.is_null());
+}
+
+ASL_TEST(niche_is_invalid)
+{
+    const asl::index_pool_handle<5, 5, uint8_t> idx{asl::niche_t{}};
+    ASL_TEST_EXPECT(idx.is_null());
+}
+
+ASL_TEST(construct)
+{
+    const asl::index_pool_handle<5, 5> idx(9, 11);
+    ASL_TEST_EXPECT(!idx.is_null());
+    ASL_TEST_EXPECT(idx.index() == 9);
+    ASL_TEST_EXPECT(idx.gen() == 11);
+}
+
+ASL_TEST(construct_user)
+{
+    const asl::index_pool_handle<5, 5, Flags, 4> idx(9, 11, kFlag2);
+    ASL_TEST_EXPECT(!idx.is_null());
+    ASL_TEST_EXPECT(idx.index() == 9);
+    ASL_TEST_EXPECT(idx.gen() == 11);
+    ASL_TEST_EXPECT(idx.user() == kFlag2);
+    static_assert(asl::same_as<Flags, decltype(idx.user())>);
+}
+
+ASL_TEST(compare) // NOLINT
+{
+    const asl::index_pool_handle<5, 5, Flags, 4> idx_default;
+    const asl::index_pool_handle<5, 5, Flags, 4> idx0;
+    const asl::index_pool_handle<5, 5, Flags, 4> idx1(9, 11, kFlag2);
+    const asl::index_pool_handle<5, 5, Flags, 4> idx2(9, 11, kFlag1);
+    const asl::index_pool_handle<5, 5, Flags, 4> idx3(9, 11, kFlag1);
+    const asl::index_pool_handle<5, 5, Flags, 4> idx4(9, 10, kFlag2);
+    const asl::index_pool_handle<5, 5, Flags, 4> idx5(8, 11, kFlag2);
+
+    ASL_TEST_EXPECT(idx0 == idx_default);
+
+    ASL_TEST_EXPECT(idx0 != idx1);
+    ASL_TEST_EXPECT(idx0 != idx2);
+    ASL_TEST_EXPECT(idx0 != idx3);
+    ASL_TEST_EXPECT(idx0 != idx4);
+    ASL_TEST_EXPECT(idx0 != idx5);
+
+    ASL_TEST_EXPECT(idx1 != idx2);
+    ASL_TEST_EXPECT(idx1 != idx3);
+    ASL_TEST_EXPECT(idx1 != idx4);
+    ASL_TEST_EXPECT(idx1 != idx5);
+
+    ASL_TEST_EXPECT(idx2 == idx3);
+    ASL_TEST_EXPECT(idx2 != idx4);
+    ASL_TEST_EXPECT(idx2 != idx5);
+
+    ASL_TEST_EXPECT(idx3 != idx4);
+    ASL_TEST_EXPECT(idx3 != idx5);
+
+    ASL_TEST_EXPECT(idx4 != idx5);
+}
+
+ASL_TEST(hashing) // NOLINT
+{
+    const asl::index_pool_handle<4, 4> idx0(asl::niche_t{});
+    const asl::index_pool_handle<4, 4> idx1{};
+    const asl::index_pool_handle<4, 4> idx2(1, 1);
+    const asl::index_pool_handle<4, 4> idx3(1, 1);
+    const asl::index_pool_handle<4, 4> idx4(2, 1);
+    const asl::index_pool_handle<4, 4> idx5(1, 2);
+
+    ASL_TEST_EXPECT(asl::hash_value(idx0) != asl::hash_value(idx1));
+    ASL_TEST_EXPECT(asl::hash_value(idx0) != asl::hash_value(idx2));
+    ASL_TEST_EXPECT(asl::hash_value(idx0) != asl::hash_value(idx3));
+    ASL_TEST_EXPECT(asl::hash_value(idx0) != asl::hash_value(idx4));
+    ASL_TEST_EXPECT(asl::hash_value(idx0) != asl::hash_value(idx5));
+
+    ASL_TEST_EXPECT(asl::hash_value(idx1) != asl::hash_value(idx2));
+    ASL_TEST_EXPECT(asl::hash_value(idx1) != asl::hash_value(idx3));
+    ASL_TEST_EXPECT(asl::hash_value(idx1) != asl::hash_value(idx4));
+    ASL_TEST_EXPECT(asl::hash_value(idx1) != asl::hash_value(idx5));
+
+    ASL_TEST_EXPECT(asl::hash_value(idx2) == asl::hash_value(idx3));
+    ASL_TEST_EXPECT(asl::hash_value(idx2) != asl::hash_value(idx4));
+    ASL_TEST_EXPECT(asl::hash_value(idx2) != asl::hash_value(idx5));
+
+    ASL_TEST_EXPECT(asl::hash_value(idx3) != asl::hash_value(idx4));
+    ASL_TEST_EXPECT(asl::hash_value(idx3) != asl::hash_value(idx5));
+
+    ASL_TEST_EXPECT(asl::hash_value(idx4) != asl::hash_value(idx5));
+}
+
+ASL_TEST(hashing_in_option) // NOLINT
+{
+    const asl::option<asl::index_pool_handle<4, 4>> idx0;
+    const asl::option<asl::index_pool_handle<4, 4>> idx1{asl::index_pool_handle<4, 4>()};
+    const asl::option<asl::index_pool_handle<4, 4>> idx2{asl::index_pool_handle<4, 4>(1, 1)};
+    const asl::option<asl::index_pool_handle<4, 4>> idx3{asl::index_pool_handle<4, 4>(1, 1)};
+    const asl::option<asl::index_pool_handle<4, 4>> idx4{asl::index_pool_handle<4, 4>(2, 1)};
+    const asl::option<asl::index_pool_handle<4, 4>> idx5{asl::index_pool_handle<4, 4>(1, 2)};
+
+    ASL_TEST_EXPECT(asl::hash_value(idx0) != asl::hash_value(idx1));
+    ASL_TEST_EXPECT(asl::hash_value(idx0) != asl::hash_value(idx2));
+    ASL_TEST_EXPECT(asl::hash_value(idx0) != asl::hash_value(idx3));
+    ASL_TEST_EXPECT(asl::hash_value(idx0) != asl::hash_value(idx4));
+    ASL_TEST_EXPECT(asl::hash_value(idx0) != asl::hash_value(idx5));
+
+    ASL_TEST_EXPECT(asl::hash_value(idx1) != asl::hash_value(idx2));
+    ASL_TEST_EXPECT(asl::hash_value(idx1) != asl::hash_value(idx3));
+    ASL_TEST_EXPECT(asl::hash_value(idx1) != asl::hash_value(idx4));
+    ASL_TEST_EXPECT(asl::hash_value(idx1) != asl::hash_value(idx5));
+
+    ASL_TEST_EXPECT(asl::hash_value(idx2) == asl::hash_value(idx3));
+    ASL_TEST_EXPECT(asl::hash_value(idx2) != asl::hash_value(idx4));
+    ASL_TEST_EXPECT(asl::hash_value(idx2) != asl::hash_value(idx5));
+
+    ASL_TEST_EXPECT(asl::hash_value(idx3) != asl::hash_value(idx4));
+    ASL_TEST_EXPECT(asl::hash_value(idx3) != asl::hash_value(idx5));
+
+    ASL_TEST_EXPECT(asl::hash_value(idx4) != asl::hash_value(idx5));
+}
+
+ASL_TEST(simple_pool) // NOLINT
+{
+    using Pool = asl::IndexPool<8, 8>;
+    Pool pool;
+
+    auto a = pool.acquire_ensure();
+    auto b = pool.acquire_ensure();
+
+    ASL_TEST_EXPECT(!a.is_null());
+    ASL_TEST_EXPECT(!b.is_null());
+    ASL_TEST_EXPECT(a.index() == 0);
+    ASL_TEST_EXPECT(b.index() == 1);
+    ASL_TEST_EXPECT(a.gen() == 0);
+    ASL_TEST_EXPECT(b.gen() == 0);
+    ASL_TEST_EXPECT(!pool.is_full());
+
+    ASL_TEST_EXPECT(a != b);
+
+    ASL_TEST_EXPECT(!pool.is_valid({}));
+    ASL_TEST_EXPECT(pool.is_valid(a));
+    ASL_TEST_EXPECT(pool.is_valid(b));
+
+    pool.release(a);
+
+    ASL_TEST_EXPECT(!pool.is_valid(a));
+    ASL_TEST_EXPECT(pool.is_valid(b));
+
+    auto c = pool.acquire_ensure();
+
+    ASL_TEST_EXPECT(!c.is_null());
+    ASL_TEST_EXPECT(c.index() == 0);
+    ASL_TEST_EXPECT(c.gen() == 1);
+
+    ASL_TEST_EXPECT(a != c);
+    ASL_TEST_EXPECT(b != c);
+
+    ASL_TEST_EXPECT(!pool.is_valid(a));
+    ASL_TEST_EXPECT(pool.is_valid(b));
+    ASL_TEST_EXPECT(pool.is_valid(c));
+
+    pool.release(b);
+
+    ASL_TEST_EXPECT(!pool.is_valid(a));
+    ASL_TEST_EXPECT(!pool.is_valid(b));
+    ASL_TEST_EXPECT(pool.is_valid(c));
+
+    pool.release(c);
+
+    ASL_TEST_EXPECT(!pool.is_valid(a));
+    ASL_TEST_EXPECT(!pool.is_valid(b));
+    ASL_TEST_EXPECT(!pool.is_valid(c));
+}
+
+ASL_TEST(pool_acquire_release_a_lot)
+{
+    using Pool = asl::IndexPool<3, 3>;
+    Pool pool;
+
+    for (int i = 0; i < 80; ++i)
+    {
+        pool.release(pool.acquire_ensure());
+        ASL_TEST_EXPECT(!pool.is_full());
+    }
+}
+
+ASL_TEST(pool_acquire_past_capacity)
+{
+    using Pool = asl::IndexPool<3, 3>;
+    Pool pool;
+
+    auto idx = pool.acquire_ensure();
+
+    for (int i = 0; i < 7; ++i)
+    {
+        ASL_TEST_EXPECT(!pool.is_full());
+        ASL_TEST_EXPECT(pool.acquire().has_value());
+    }
+
+    for (int i = 0; i < 8; ++i)
+    {
+        ASL_TEST_EXPECT(pool.is_full());
+        ASL_TEST_EXPECT(!pool.acquire().has_value());
+    }
+
+    pool.release(idx);
+    ASL_TEST_EXPECT(!pool.is_full());
+    ASL_TEST_EXPECT(pool.acquire().has_value());
+    ASL_TEST_EXPECT(pool.is_full());
+    ASL_TEST_EXPECT(!pool.acquire().has_value());
+}
+
+ASL_TEST(pool_with_user_type)
+{
+    using Pool = asl::IndexPool<8, 8, Flags, 4>;
+    Pool pool;
+
+    const auto a = pool.acquire_ensure(kFlag0);
+    const auto b = pool.acquire_ensure(kFlag2);
+
+    ASL_TEST_EXPECT(a.user() == kFlag0);
+    ASL_TEST_EXPECT(b.user() == kFlag2);
+}
+
+ASL_TEST(pool_with_payload)
+{
+    using Pool = asl::IndexPool<8, 8, asl::empty, 0, int>;
+    Pool pool;
+
+    const auto a = pool.acquire_ensure(37);
+    const auto b = pool.acquire_ensure(28);
+
+    ASL_TEST_EXPECT(*pool.get_payload(a) == 37);
+    ASL_TEST_EXPECT(*pool.get_payload(b) == 28);
+    ASL_TEST_EXPECT(pool.get_payload({}) == nullptr);
+
+    pool.release(a);
+
+    ASL_TEST_EXPECT(pool.get_payload(a) == nullptr);
+    ASL_TEST_EXPECT(*pool.get_payload(b) == 28);
+}
+
+ASL_TEST(pool_with_payload_and_user)
+{
+    using Pool = asl::IndexPool<8, 8, Flags, 8, int>;
+    Pool pool;
+
+    const auto a = pool.acquire_ensure(kFlag1, 37);
+    const auto b = pool.acquire_ensure(kFlag0, 28);
+
+    ASL_TEST_EXPECT(a.user() == kFlag1);
+    ASL_TEST_EXPECT(b.user() == kFlag0);
+
+    ASL_TEST_EXPECT(*pool.get_payload(a) == 37);
+    ASL_TEST_EXPECT(*pool.get_payload(b) == 28);
+    ASL_TEST_EXPECT(pool.get_payload({}) == nullptr);
+
+    pool.release(a);
+
+    ASL_TEST_EXPECT(pool.get_payload(a) == nullptr);
+    ASL_TEST_EXPECT(*pool.get_payload(b) == 28);
+}
+
+ASL_TEST(pool_exchange_payload)
+{
+    using Pool = asl::IndexPool<8, 8, asl::empty, 0, int>;
+    Pool pool;
+
+    const auto a = pool.acquire_ensure(37);
+    const auto b = pool.acquire_ensure(28);
+
+    ASL_TEST_EXPECT(*pool.get_payload(a) == 37);
+    ASL_TEST_EXPECT(*pool.get_payload(b) == 28);
+
+    ASL_TEST_EXPECT(!pool.exchange_payload({}, 0).has_value());
+
+    ASL_TEST_EXPECT(pool.exchange_payload(a, 101).value() == 37);
+    ASL_TEST_EXPECT(pool.exchange_payload(b, 102).value() == 28);
+
+    ASL_TEST_EXPECT(*pool.get_payload(a) == 101);
+    ASL_TEST_EXPECT(*pool.get_payload(b) == 102);
+}
+
--- a/asl/handle_pool/sparse_handle_pool.hpp
+++ b/asl/handle_pool/sparse_handle_pool.hpp
@ -0,0 +1,158 @@
+// Copyright 2025 Steven Le Rouzic
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#pragma once
+
+#include "asl/handle_pool/index_pool.hpp"
+#include "asl/memory/allocator.hpp"
+#include "asl/containers/chunked_buffer.hpp"
+
+
+namespace asl
+{
+
+// @Todo If we want the allocator to be non-copyable, we could
+// introduce a reference allocator type that is copyable, and store
+// the "main" allocator in the pool.
+
+template<
+    is_object T,
+    int kIndexBits,
+    int kGenBits,
+    typename UserType = empty,
+    int kUserBits = 0,
+    isize_t kChunkSize = 32,
+    allocator Allocator = DefaultAllocator>
+requires copyable<Allocator>
+class SparseHandlePool
+{
+    using ThisIndexPool = IndexPool<kIndexBits, kGenBits, UserType, kUserBits, empty, Allocator>;
+
+    struct Slot
+    {
+        ThisIndexPool::handle h;
+        maybe_uninit<T> obj;
+
+        Slot() = default;
+        ASL_DELETE_COPY_MOVE(Slot);
+
+        ~Slot()
+        {
+            if (!h.is_null())
+            {
+                obj.destroy_unsafe();
+            }
+        }
+    };
+
+    using Buffer = chunked_buffer<Slot, kChunkSize, Allocator>;
+
+    ThisIndexPool m_index_pool{};
+    Buffer        m_buffer{};
+
+    using config = ThisIndexPool::handle::config;
+
+    template<typename... Args>
+    void set_object(ThisIndexPool::handle h, Args&&... args)
+    {
+        const auto index = static_cast<isize_t>(h.index());
+        if (m_buffer.size() <= index)
+        {
+            m_buffer.resize(index + 1);
+        }
+        m_buffer[index].h = h;
+        m_buffer[index].obj.construct_unsafe(std::forward<Args>(args)...);
+    }
+
+public:
+    using handle = ThisIndexPool::handle;
+
+    SparseHandlePool() requires default_constructible<Allocator> = default;
+
+    explicit SparseHandlePool(const Allocator& allocator)
+        : m_index_pool(allocator)
+        , m_buffer(allocator)
+    {}
+
+    ASL_DELETE_COPY(SparseHandlePool);
+    ASL_DEFAULT_MOVE(SparseHandlePool);
+    ~SparseHandlePool() = default;
+
+    [[nodiscard]] bool is_full() const
+    {
+        return m_index_pool.is_full();
+    }
+
+    bool is_valid(handle h) const
+    {
+        return m_index_pool.is_valid(h);
+    }
+
+    template<typename... Args>
+    option<handle> acquire(config::UserType user, Args&&... args)
+        requires config::kHasUser && constructible_from<T, Args&&...>
+    {
+        if (is_full()) { return nullopt; }
+        const auto handle = m_index_pool.acquire_ensure(user);
+        set_object(handle, std::forward<Args>(args)...);
+        return handle;
+    }
+
+    template<typename... Args>
+    option<handle> acquire(Args&&... args)
+        requires (!config::kHasUser) && constructible_from<T, Args&&...>
+    {
+        if (is_full()) { return nullopt; }
+        const auto handle = m_index_pool.acquire_ensure();
+        set_object(handle, std::forward<Args>(args)...);
+        return handle;
+    }
+
+    template<typename... Args>
+    handle acquire_ensure(config::UserType user, Args&&... args)
+        requires config::kHasUser && constructible_from<T, Args&&...>
+    {
+        ASL_ASSERT_RELEASE(!is_full());
+        const auto handle = m_index_pool.acquire_ensure(user);
+        set_object(handle, std::forward<Args>(args)...);
+        return handle;
+    }
+
+    template<typename... Args>
+    handle acquire_ensure(Args&&... args)
+        requires (!config::kHasUser) && constructible_from<T, Args&&...>
+    {
+        ASL_ASSERT_RELEASE(!is_full());
+        const auto handle = m_index_pool.acquire_ensure();
+        set_object(handle, std::forward<Args>(args)...);
+        return handle;
+    }
+
+    void release(handle h)
+    {
+        if (!is_valid(h)) { return; }
+        auto& slot = m_buffer[static_cast<isize_t>(h.index())];
+        slot.h = {};
+        slot.obj.destroy_unsafe();
+        m_index_pool.release(h);
+    }
+
+    auto get(this auto&& self, handle h)
+        -> copy_const_t<un_ref_t<decltype(self)>, T>*
+    {
+        if (!self.is_valid(h)) { return nullptr; }
+        return &std::forward<decltype(self)>(self).m_buffer[static_cast<isize_t>(h.index())]
+            .obj.as_init_unsafe();
+    }
+
+    auto get_ensure(this auto&& self, handle h)
+        -> copy_cref_t<decltype(self), T>
+    {
+        ASL_ASSERT_RELEASE(self.is_valid(h));
+        return std::forward<decltype(self)>(self).m_buffer[static_cast<isize_t>(h.index())]
+            .obj.as_init_unsafe();
+    }
+};
+
+} // namespace asl
--- a/asl/handle_pool/sparse_handle_pool_tests.cpp
+++ b/asl/handle_pool/sparse_handle_pool_tests.cpp
@ -0,0 +1,117 @@
+// Copyright 2025 Steven Le Rouzic
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#include "asl/testing/testing.hpp"
+#include "asl/tests/types.hpp"
+#include "asl/handle_pool/sparse_handle_pool.hpp"
+
+ASL_TEST(acquire_release) // NOLINT
+{
+    asl::SparseHandlePool<int, 1, 1> pool;
+
+    ASL_TEST_EXPECT(!pool.is_full());
+
+    const auto a = pool.acquire_ensure(6);
+    const auto b = pool.acquire_ensure(7);
+
+    ASL_TEST_EXPECT(pool.is_valid(a));
+    ASL_TEST_EXPECT(pool.is_valid(b));
+    ASL_TEST_EXPECT(pool.is_full());
+
+    ASL_TEST_EXPECT(pool.get_ensure(a) == 6);
+    ASL_TEST_EXPECT(pool.get_ensure(b) == 7);
+
+    pool.release(a);
+    ASL_TEST_EXPECT(!pool.is_valid(a));
+    ASL_TEST_EXPECT(pool.is_valid(b));
+    ASL_TEST_EXPECT(!pool.is_full());
+    ASL_TEST_EXPECT(pool.get(a) == nullptr);
+    ASL_TEST_EXPECT(*pool.get(b) == 7);
+
+    const auto c = pool.acquire_ensure(8);
+
+    ASL_TEST_EXPECT(!pool.is_valid(a));
+    ASL_TEST_EXPECT(pool.is_valid(b));
+    ASL_TEST_EXPECT(pool.is_valid(c));
+    ASL_TEST_EXPECT(pool.is_full());
+
+    ASL_TEST_EXPECT(*pool.get(b) == 7);
+    ASL_TEST_EXPECT(*pool.get(c) == 8);
+    ASL_TEST_EXPECT(pool.get(a) == nullptr);
+}
+
+ASL_TEST(element_destructor)
+{
+    asl::SparseHandlePool<DestructorObserver, 8, 8> pool;
+    bool d[3]{};
+
+    const auto d0 = pool.acquire_ensure(&d[0]);
+    const auto d1 = pool.acquire_ensure(&d[1]);
+    const auto d2 = pool.acquire_ensure(&d[2]);
+
+    ASL_TEST_EXPECT(!d[0]);
+    ASL_TEST_EXPECT(!d[1]);
+    ASL_TEST_EXPECT(!d[2]);
+
+    pool.release(d1);
+    ASL_TEST_EXPECT(!d[0]);
+    ASL_TEST_EXPECT(d[1]);
+    ASL_TEST_EXPECT(!d[2]);
+
+    pool.release(d0);
+    ASL_TEST_EXPECT(d[0]);
+    ASL_TEST_EXPECT(d[1]);
+    ASL_TEST_EXPECT(!d[2]);
+
+    pool.release(d2);
+    ASL_TEST_EXPECT(d[0]);
+    ASL_TEST_EXPECT(d[1]);
+    ASL_TEST_EXPECT(d[2]);
+}
+
+ASL_TEST(destructor)
+{
+    bool d[3]{};
+
+    {
+        asl::SparseHandlePool<DestructorObserver, 8, 8> pool;
+
+        pool.acquire_ensure(&d[0]);
+        const auto d1 = pool.acquire_ensure(&d[1]);
+        pool.acquire_ensure(&d[2]);
+
+        ASL_TEST_EXPECT(!d[0]);
+        ASL_TEST_EXPECT(!d[1]);
+        ASL_TEST_EXPECT(!d[2]);
+
+        pool.release(d1);
+        ASL_TEST_EXPECT(!d[0]);
+        ASL_TEST_EXPECT(d[1]);
+        ASL_TEST_EXPECT(!d[2]);
+    }
+
+    ASL_TEST_EXPECT(d[0]);
+    ASL_TEST_EXPECT(d[1]);
+    ASL_TEST_EXPECT(d[2]);
+}
+
+enum Flags : uint8_t
+{
+    kFlag1 = 1,
+    kFlag2 = 2,
+};
+
+ASL_TEST(user_type)
+{
+    asl::SparseHandlePool<int, 8, 8, Flags> pool;
+
+    auto a = pool.acquire_ensure(kFlag2, 22);
+    auto b = pool.acquire_ensure(kFlag1, 11);
+
+    ASL_TEST_EXPECT(pool.get_ensure(a) == 22);
+    ASL_TEST_EXPECT(pool.get_ensure(b) == 11);
+
+    ASL_TEST_EXPECT(a.user() == kFlag2);
+    ASL_TEST_EXPECT(b.user() == kFlag1);
+}
--- a/asl/logging/logging.hpp
+++ b/asl/logging/logging.hpp
@ -87,9 +87,26 @@ void log(level l, const source_location& sl, string_view fmt, const Args&... arg

 } // namespace asl::log

-// @Todo Compile-time configuration of logging
+#if !defined(ASL_LOG_LEVEL) || ASL_LOG_LEVEL >= 4
+    #define ASL_LOG_DEBUG(...)   ::asl::log::log(::asl::log::kDebug,   ::asl::source_location{}, __VA_ARGS__)
+#else
+    #define ASL_LOG_DEBUG(...)
+#endif

-#define ASL_LOG_DEBUG(...) ::asl::log::log(::asl::log::kDebug, ::asl::source_location{}, __VA_ARGS__)
-#define ASL_LOG_INFO(...) ::asl::log::log(::asl::log::kInfo, ::asl::source_location{}, __VA_ARGS__)
-#define ASL_LOG_WARNING(...) ::asl::log::log(::asl::log::kWarning, ::asl::source_location{}, __VA_ARGS__)
-#define ASL_LOG_ERROR(...) ::asl::log::log(::asl::log::kError, ::asl::source_location{}, __VA_ARGS__)
+#if !defined(ASL_LOG_LEVEL) || ASL_LOG_LEVEL >= 3
+    #define ASL_LOG_INFO(...)    ::asl::log::log(::asl::log::kInfo,    ::asl::source_location{}, __VA_ARGS__)
+#else
+    #define ASL_LOG_DEBUG(...)
+#endif
+
+#if !defined(ASL_LOG_LEVEL) || ASL_LOG_LEVEL >= 2
+    #define ASL_LOG_WARNING(...) ::asl::log::log(::asl::log::kWarning, ::asl::source_location{}, __VA_ARGS__)
+#else
+    #define ASL_LOG_DEBUG(...)
+#endif
+
+#if !defined(ASL_LOG_LEVEL) || ASL_LOG_LEVEL >= 1
+    #define ASL_LOG_ERROR(...)   ::asl::log::log(::asl::log::kError,   ::asl::source_location{}, __VA_ARGS__)
+#else
+    #define ASL_LOG_DEBUG(...)
+#endif
--- a/asl/memory/BUILD.bazel
+++ b/asl/memory/BUILD.bazel
@ -9,16 +9,27 @@ package(
 cc_library(
    name = "memory",
    hdrs = [
-        "allocator.hpp",
        "layout.hpp",
        "memory.hpp",
    ],
-    srcs = [
-        "allocator.cpp",
-    ],
    deps = [
        "//asl/base",
    ],
    visibility = ["//visibility:public"],
 )

+cc_library(
+    name = "allocator",
+    hdrs = [
+        "allocator.hpp",
+    ],
+    srcs = [
+        "allocator.cpp",
+    ],
+    deps = [
+        "//asl/base",
+        "//asl/memory",
+    ],
+    visibility = ["//visibility:public"],
+)
+
--- a/asl/memory/allocator.cpp
+++ b/asl/memory/allocator.cpp
@ -4,6 +4,7 @@

 #include "asl/memory/allocator.hpp"
 #include "asl/base/assert.hpp"
+#include "asl/base/numeric.hpp"
 #include "asl/memory/layout.hpp"

 #include <cstdlib>
@ -14,11 +15,11 @@

 void* asl::GlobalHeap::alloc(const layout& layout)
 {
-#if ASL_OS_WINDOWS
+#if defined(ASL_OS_WINDOWS)
    void* ptr = ::_aligned_malloc(
        static_cast<size_t>(layout.size),
        static_cast<size_t>(layout.align));
-#elif ASL_OS_LINUX
+#elif defined(ASL_OS_LINUX)
    void* ptr = ::aligned_alloc(
        static_cast<size_t>(layout.align),
        static_cast<size_t>(layout.size));
@ -29,11 +30,11 @@ void* asl::GlobalHeap::alloc(const layout& layout)

 void* asl::GlobalHeap::realloc(void* old_ptr, [[maybe_unused]] const layout& old_layout, const layout& new_layout)
 {
-#if ASL_OS_WINDOWS
+#if defined(ASL_OS_WINDOWS)
    return ::_aligned_realloc(old_ptr,
        static_cast<size_t>(new_layout.size),
        static_cast<size_t>(new_layout.align));
-#elif ASL_OS_LINUX
+#elif defined(ASL_OS_LINUX)
    if (new_layout.align <= old_layout.align)
    {
        void* new_ptr = ::realloc(old_ptr, static_cast<size_t>(new_layout.size));
@ -50,9 +51,9 @@ void* asl::GlobalHeap::realloc(void* old_ptr, [[maybe_unused]] const layout& old

 void asl::GlobalHeap::dealloc(void* ptr, const layout&)
 {
-#if ASL_OS_WINDOWS
+#if defined(ASL_OS_WINDOWS)
    ::_aligned_free(ptr);
-#elif ASL_OS_LINUX
+#elif defined(ASL_OS_LINUX)
    ::free(ptr);
 #endif
 }
--- a/asl/memory/allocator.hpp
+++ b/asl/memory/allocator.hpp
@ -40,6 +40,21 @@ T* alloc_new(allocator auto& a, auto&&... args)
    return construct_at<T>(ptr, std::forward<decltype(args)>(args)...);
 }

+template<typename T>
+T* alloc_uninit(allocator auto& a)
+    requires trivially_default_constructible<T>
+{
+    void* ptr = a.alloc(layout::of<T>());
+    return reinterpret_cast<T*>(ptr); // NOLINT(*-reinterpret-cast)
+}
+
+template<typename T>
+T* alloc_uninit_unsafe(allocator auto& a)
+{
+    void* ptr = a.alloc(layout::of<T>());
+    return reinterpret_cast<T*>(ptr); // NOLINT(*-reinterpret-cast)
+}
+
 template<typename T>
 void alloc_delete(allocator auto& a, T* ptr)
 {
--- a/asl/memory/memory.hpp
+++ b/asl/memory/memory.hpp
@ -17,6 +17,17 @@ constexpr void* operator new(size_t, void* ptr) noexcept
 namespace asl
 {

+template<typename T>
+[[nodiscard]]
+constexpr T* address_of(T& obj)
+{
+    return __builtin_addressof(obj);
+}
+
+template<typename T>
+void address_of(const T&& obj) = delete;
+
+[[nodiscard]]
 constexpr isize_t memcmp(const void* a, const void* b, isize_t size)
 {
    return __builtin_memcmp(a, b, static_cast<size_t>(size));
--- a/asl/strings/BUILD.bazel
+++ b/asl/strings/BUILD.bazel
@ -45,6 +45,24 @@ cc_library(
    visibility = ["//visibility:public"],
 )

+cc_library(
+    name = "parse_number",
+    hdrs = [
+        "parse_number.hpp",
+    ],
+    srcs = [
+        "parse_number_float.cpp",
+        "parse_number.cpp",
+    ],
+    deps = [
+        "//asl/base",
+        "//asl/types:status",
+        ":string_view",
+        "//vendor/fast_float",
+    ],
+    visibility = ["//visibility:public"],
+)
+
 [cc_test(
    name = "%s_tests" % name,
    srcs = [
@ -54,6 +72,7 @@ cc_library(
        ":string",
        ":string_builder",
        ":string_view",
+        ":parse_number",
        "//asl/tests:utils",
        "//asl/testing",
    ],
@ -61,4 +80,5 @@ cc_library(
    "string",
    "string_view",
    "string_builder",
+    "parse_number",
 ]]
--- a/asl/strings/parse_number.cpp
+++ b/asl/strings/parse_number.cpp
@ -0,0 +1,162 @@
+// Copyright 2025 Steven Le Rouzic
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#include "asl/strings/parse_number.hpp"
+
+namespace asl
+{
+
+bool parse_float_impl(const char** begin, const char* end, float*);
+bool parse_double_impl(const char** begin, const char* end, double*);
+
+} // namespace asl
+
+asl::status_or<asl::parse_number_result<float32_t>> asl::parse_float32(asl::string_view sv)
+{
+    const auto* begin = sv.data();
+    // NOLINTNEXTLINE(*-pointer-arithmetic)
+    const auto* end = begin + sv.size();
+    if (float32_t value{}; parse_float_impl(&begin, end, &value))
+    {
+        return parse_number_result<float32_t>{
+            .value     = value,
+            .remaining = string_view{begin, end},
+        };
+    }
+    return invalid_argument_error();
+}
+
+asl::status_or<asl::parse_number_result<float64_t>> asl::parse_float64(asl::string_view sv)
+{
+    const auto* begin = sv.data();
+    // NOLINTNEXTLINE(*-pointer-arithmetic)
+    const auto* end = begin + sv.size();
+    if (float64_t value{}; parse_double_impl(&begin, end, &value))
+    {
+        return parse_number_result<float64_t>{
+            .value     = value,
+            .remaining = string_view{begin, end},
+        };
+    }
+    return invalid_argument_error();
+}
+
+namespace
+{
+
+constexpr int8_t kBase16Table[256] = {
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+     0,  1,  2,  3,  4,  5,  6,  7,  8,  9, -1, -1, -1, -1, -1, -1,
+    -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+};
+
+// @Todo Maybe monomorph this for common bases (2, 16, 10)?
+
+template<typename T>
+asl::status_or<asl::parse_number_result<T>> parse_integer(asl::string_view sv, int base)
+{
+    ASL_ASSERT(base >= 2 && base <= 16);
+
+    if (sv.is_empty()) { return asl::invalid_argument_error(); }
+
+    T value = 0;
+    bool is_negative = false;
+
+    if (asl::is_signed_integer<T> && sv[0] == '-')
+    {
+        is_negative = true;
+        sv = sv.substr(1);
+    }
+
+    isize_t cursor = 0;
+    while (cursor < sv.size())
+    {
+        // NOLINTNEXTLINE(*-array-index)
+        int8_t digit = kBase16Table[static_cast<uint8_t>(sv[cursor])];
+        if (digit < 0 || digit >= base) { break; }
+
+        if (__builtin_mul_overflow(value, static_cast<T>(base), &value))
+        {
+            return asl::invalid_argument_error("overflow");
+        }
+
+        if (asl::is_signed_integer<T> && is_negative)
+        {
+            digit = static_cast<int8_t>(-digit);
+        }
+
+        if (__builtin_add_overflow(value, static_cast<T>(digit), &value))
+        {
+            return asl::invalid_argument_error("overflow");
+        }
+
+        cursor += 1;
+    }
+
+    if (cursor == 0)
+    {
+        return asl::invalid_argument_error();
+    }
+
+    return asl::parse_number_result<T>{
+        .value     = value,
+        .remaining = sv.substr(cursor),
+    };
+}
+
+} // anonymous namespace
+
+asl::status_or<asl::parse_number_result<uint8_t>> asl::parse_uint8(string_view sv, int base)
+{
+    return parse_integer<uint8_t>(sv, base);
+}
+
+asl::status_or<asl::parse_number_result<uint16_t>> asl::parse_uint16(string_view sv, int base)
+{
+    return parse_integer<uint16_t>(sv, base);
+}
+
+asl::status_or<asl::parse_number_result<uint32_t>> asl::parse_uint32(string_view sv, int base)
+{
+    return parse_integer<uint32_t>(sv, base);
+}
+
+asl::status_or<asl::parse_number_result<uint64_t>> asl::parse_uint64(string_view sv, int base)
+{
+    return parse_integer<uint64_t>(sv, base);
+}
+
+asl::status_or<asl::parse_number_result<int8_t>> asl::parse_int8(string_view sv, int base)
+{
+    return parse_integer<int8_t>(sv, base);
+}
+
+asl::status_or<asl::parse_number_result<int16_t>> asl::parse_int16(string_view sv, int base)
+{
+    return parse_integer<int16_t>(sv, base);
+}
+
+asl::status_or<asl::parse_number_result<int32_t>> asl::parse_int32(string_view sv, int base)
+{
+    return parse_integer<int32_t>(sv, base);
+}
+
+asl::status_or<asl::parse_number_result<int64_t>> asl::parse_int64(string_view sv, int base)
+{
+    return parse_integer<int64_t>(sv, base);
+}
+
--- a/asl/strings/parse_number.hpp
+++ b/asl/strings/parse_number.hpp
@ -0,0 +1,35 @@
+// Copyright 2025 Steven Le Rouzic
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#pragma once
+
+#include "asl/types/status_or.hpp"
+#include "asl/strings/string_view.hpp"
+#include "asl/base/float.hpp"
+
+namespace asl
+{
+
+template<typename T>
+struct parse_number_result
+{
+    T value;
+    string_view remaining;
+};
+
+status_or<parse_number_result<float32_t>> parse_float32(string_view);
+status_or<parse_number_result<float64_t>> parse_float64(string_view);
+
+status_or<parse_number_result<uint8_t>>  parse_uint8(string_view, int base = 10);
+status_or<parse_number_result<uint16_t>> parse_uint16(string_view, int base = 10);
+status_or<parse_number_result<uint32_t>> parse_uint32(string_view, int base = 10);
+status_or<parse_number_result<uint64_t>> parse_uint64(string_view, int base = 10);
+
+status_or<parse_number_result<int8_t>>  parse_int8(string_view, int base = 10);
+status_or<parse_number_result<int16_t>> parse_int16(string_view, int base = 10);
+status_or<parse_number_result<int32_t>> parse_int32(string_view, int base = 10);
+status_or<parse_number_result<int64_t>> parse_int64(string_view, int base = 10);
+
+} // namespace asl
+
--- a/asl/strings/parse_number_float.cpp
+++ b/asl/strings/parse_number_float.cpp
@ -0,0 +1,35 @@
+// Copyright 2025 Steven Le Rouzic
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Weverything"
+#include <fast_float.h>
+#pragma clang diagnostic pop
+
+// We need to isolate fast_float.h completely from asl
+// because it conflicts with our redefinitions of things
+// from the STL. In this case it's operator new, but there
+// might be other conflicts.
+
+#pragma clang diagnostic ignored "-Wmissing-prototypes"
+
+namespace asl
+{
+
+extern bool parse_float_impl(const char** begin, const char* end, float* value)
+{
+    auto res = fast_float::from_chars(*begin, end, *value);
+    *begin = res.ptr;
+    return res.ec == std::errc{};
+}
+
+extern bool parse_double_impl(const char** begin, const char* end, double* value)
+{
+    auto res = fast_float::from_chars(*begin, end, *value);
+    *begin = res.ptr;
+    return res.ec == std::errc{};
+}
+
+} // namespace asl
+
--- a/asl/strings/parse_number_integer_table.py
+++ b/asl/strings/parse_number_integer_table.py
@ -0,0 +1,24 @@
+a = ord('a')
+f = ord('f')
+A = ord('A')
+F = ord('F')
+n0 = ord('0')
+n9 = ord('9')
+
+output = ""
+
+for i in range(0, 16):
+    for j in range(0, 16):
+        v = i * 16 + j
+        n = -1
+        if v >= a and v <= f:
+            n = v - a + 10
+        elif v >= A and v <= F:
+            n = v - A + 10
+        elif v >= n0 and v <= n9:
+            n = v - n0
+        output += f"{n:>2}, "
+    output += "\n"
+
+print(output)
+
--- a/asl/strings/parse_number_tests.cpp
+++ b/asl/strings/parse_number_tests.cpp
@ -0,0 +1,201 @@
+// Copyright 2025 Steven Le Rouzic
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#include "asl/strings/parse_number.hpp"
+#include "asl/base/numeric.hpp"
+#include "asl/testing/testing.hpp"
+
+ASL_TEST(parse_float_error)
+{
+    const asl::string_view sv = "this is not a number lmao";
+    auto res = asl::parse_float32(sv);
+    ASL_TEST_EXPECT(!res.ok());
+}
+
+ASL_TEST(parse_float_empty)
+{
+    const asl::string_view sv = "";
+    auto res = asl::parse_float32(sv);
+    ASL_TEST_EXPECT(!res.ok());
+}
+
+ASL_TEST(parse_float_simple)
+{
+    const asl::string_view sv = "3.1415";
+    auto res = asl::parse_float32(sv);
+    ASL_TEST_EXPECT(res.ok());
+    ASL_TEST_EXPECT(asl::are_nearly_equal(res.value().value, 3.1415F));
+    ASL_TEST_EXPECT(res.value().remaining.size() == 0);
+}
+
+ASL_TEST(parse_float_integer)
+{
+    const asl::string_view sv = "31415";
+    auto res = asl::parse_float32(sv);
+    ASL_TEST_EXPECT(res.ok());
+    ASL_TEST_EXPECT(res.value().value == 31415.0F);
+    ASL_TEST_EXPECT(res.value().remaining.size() == 0);
+}
+
+ASL_TEST(parse_float_scientific)
+{
+    const asl::string_view sv = "314.15e-2";
+    auto res = asl::parse_float32(sv);
+    ASL_TEST_EXPECT(res.ok());
+    ASL_TEST_EXPECT(asl::are_nearly_equal(res.value().value, 3.1415F));
+    ASL_TEST_EXPECT(res.value().remaining.size() == 0);
+}
+
+ASL_TEST(parse_float_suffix)
+{
+    const asl::string_view sv = "3.1415 yoyoyo";
+    auto res = asl::parse_float32(sv);
+    ASL_TEST_EXPECT(res.ok());
+    ASL_TEST_EXPECT(asl::are_nearly_equal(res.value().value, 3.1415F));
+    ASL_TEST_EXPECT(res.value().remaining == " yoyoyo");
+}
+
+ASL_TEST(parse_int)
+{
+    const asl::string_view sv = "926473";
+    auto res = asl::parse_uint32(sv);
+    ASL_TEST_EXPECT(res.ok());
+    ASL_TEST_EXPECT(res.value().value == 926473);
+    ASL_TEST_EXPECT(res.value().remaining.is_empty());
+}
+
+ASL_TEST(parse_int_negative)
+{
+    const asl::string_view sv = "-926473";
+    auto res = asl::parse_int32(sv);
+    ASL_TEST_EXPECT(res.ok());
+    ASL_TEST_EXPECT(res.value().value == -926473);
+    ASL_TEST_EXPECT(res.value().remaining.is_empty());
+}
+
+ASL_TEST(parse_int_suffix)
+{
+    const asl::string_view sv = "926473 what's this then";
+    auto res = asl::parse_uint32(sv);
+    ASL_TEST_EXPECT(res.ok());
+    ASL_TEST_EXPECT(res.value().value == 926473);
+    ASL_TEST_EXPECT(res.value().remaining == " what's this then");
+}
+
+ASL_TEST(parse_uint_with_minus)
+{
+    const asl::string_view sv = "-926473";
+    auto res = asl::parse_uint32(sv);
+    ASL_TEST_EXPECT(!res.ok());
+}
+
+ASL_TEST(parse_int_with_only_minus)
+{
+    const asl::string_view sv = "-@";
+    auto res = asl::parse_int32(sv);
+    ASL_TEST_EXPECT(!res.ok());
+}
+
+ASL_TEST(parse_uint_invalid)
+{
+    const asl::string_view sv = "abcd";
+    auto res = asl::parse_uint32(sv);
+    ASL_TEST_EXPECT(!res.ok());
+}
+
+ASL_TEST(parse_uint_empty)
+{
+    const asl::string_view sv = "";
+    auto res = asl::parse_uint32(sv);
+    ASL_TEST_EXPECT(!res.ok());
+}
+
+ASL_TEST(parse_uint_overflow)
+{
+    ASL_TEST_EXPECT(!asl::parse_uint16("80000").ok());
+    ASL_TEST_EXPECT(!asl::parse_uint16("65536").ok());
+}
+
+ASL_TEST(parse_uint16_max)
+{
+    const asl::string_view sv = "65535";
+    auto res = asl::parse_uint16(sv);
+    ASL_TEST_EXPECT(res.ok());
+    ASL_TEST_EXPECT(res.value().value == 65535);
+    ASL_TEST_EXPECT(res.value().remaining.is_empty());
+}
+
+ASL_TEST(parse_uint16_zero)
+{
+    const asl::string_view sv = "0";
+    auto res = asl::parse_uint16(sv);
+    ASL_TEST_EXPECT(res.ok());
+    ASL_TEST_EXPECT(res.value().value == 0);
+    ASL_TEST_EXPECT(res.value().remaining.is_empty());
+}
+
+ASL_TEST(parse_uint16_zeros)
+{
+    const asl::string_view sv = "00000";
+    auto res = asl::parse_uint16(sv);
+    ASL_TEST_EXPECT(res.ok());
+    ASL_TEST_EXPECT(res.value().value == 0);
+    ASL_TEST_EXPECT(res.value().remaining.is_empty());
+}
+
+ASL_TEST(parse_int_overflow)
+{
+    ASL_TEST_EXPECT(!asl::parse_int16("80000").ok());
+    ASL_TEST_EXPECT(!asl::parse_int16("40000").ok());
+    ASL_TEST_EXPECT(!asl::parse_int16("32768").ok());
+    ASL_TEST_EXPECT(!asl::parse_int16("-80000").ok());
+    ASL_TEST_EXPECT(!asl::parse_int16("-40000").ok());
+    ASL_TEST_EXPECT(!asl::parse_int16("-32769").ok());
+}
+
+ASL_TEST(parse_int16_max)
+{
+    const asl::string_view sv = "32767";
+    auto res = asl::parse_int16(sv);
+    ASL_TEST_EXPECT(res.ok());
+    ASL_TEST_EXPECT(res.value().value == 32767);
+    ASL_TEST_EXPECT(res.value().remaining.is_empty());
+}
+
+ASL_TEST(parse_int16_min)
+{
+    const asl::string_view sv = "-32768";
+    auto res = asl::parse_int16(sv);
+    ASL_TEST_EXPECT(res.ok());
+    ASL_TEST_EXPECT(res.value().value == -32768);
+    ASL_TEST_EXPECT(res.value().remaining.is_empty());
+}
+
+ASL_TEST(parse_hex)
+{
+    const asl::string_view sv = "1000a";
+    auto res = asl::parse_uint32(sv, 16);
+    ASL_TEST_EXPECT(res.ok());
+    ASL_TEST_EXPECT(res.value().value == 65546);
+    ASL_TEST_EXPECT(res.value().remaining.is_empty());
+}
+
+ASL_TEST(parse_bin)
+{
+    const asl::string_view sv = "101010";
+    auto res = asl::parse_uint32(sv, 2);
+    ASL_TEST_EXPECT(res.ok());
+    ASL_TEST_EXPECT(res.value().value == 42);
+    ASL_TEST_EXPECT(res.value().remaining.is_empty());
+}
+
+ASL_TEST(parse_oct)
+{
+    const asl::string_view sv = "644";
+    auto res = asl::parse_uint32(sv, 8);
+    ASL_TEST_EXPECT(res.ok());
+    ASL_TEST_EXPECT(res.value().value == 6 * 64 + 4 * 8 + 4);
+    ASL_TEST_EXPECT(res.value().remaining.is_empty());
+}
+
--- a/asl/strings/string_view.hpp
+++ b/asl/strings/string_view.hpp
@ -28,6 +28,13 @@ public:
        , m_size{size}
    {}

+    constexpr string_view(const char* begin, const char* end)
+        : m_data{begin}
+        , m_size{end - begin}
+    {
+        ASL_ASSERT(begin <= end);
+    }
+
    template<isize_t kSize>
    constexpr string_view(const char (&str)[kSize]) // NOLINT(*explicit*)
        requires (kSize >= 1)
--- a/asl/testing/testing.cpp
+++ b/asl/testing/testing.cpp
@ -69,7 +69,7 @@ int main([[maybe_unused]] int argc, [[maybe_unused]] char* argv[])

    asl::testing::Test* failed_head = nullptr;

-    for (auto* it = g_state.head; it != nullptr; it = it->m_next)
+    for (auto* it = g_state.head; it != nullptr;)
    {
        asl::eprint(GREEN("[ RUN      ]") " {}\n", it->m_case_name);

@ -80,13 +80,17 @@ int main([[maybe_unused]] int argc, [[maybe_unused]] char* argv[])
        {
            asl::eprint(GREEN("[       OK ]") " {}\n", it->m_case_name);
            pass += 1;
+            it = it->m_next;
        }
        else
        {
            asl::eprint(RED("[  FAILED  ]") " {}\n", it->m_case_name);
            fail += 1;

-            it->m_next = asl::exchange(failed_head, it);
+            auto* this_test = it;
+            it = it->m_next;
+
+            this_test->m_next = asl::exchange(failed_head, this_test);
        }
    }

--- a/asl/tests/BUILD.bazel
+++ b/asl/tests/BUILD.bazel
@ -9,10 +9,12 @@ package(
 cc_library(
    name = "utils",
    hdrs = [
+        "counting_allocator.hpp",
        "types.hpp",
    ],
    deps = [
        "//asl/base",
+        "//asl/memory:allocator",
    ],
    visibility = ["//asl:__subpackages__"],
 )
--- a/asl/tests/counting_allocator.hpp
+++ b/asl/tests/counting_allocator.hpp
@ -0,0 +1,48 @@
+// Copyright 2025 Steven Le Rouzic
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#include "asl/memory/allocator.hpp"
+
+struct CountingAllocator
+{
+    struct Stats
+    {
+        isize_t alloc_count{};
+        isize_t realloc_count{};
+        isize_t dealloc_count{};
+        isize_t alive_bytes{};
+
+        [[nodiscard]] constexpr isize_t any_alloc_count() const
+        {
+            return alloc_count + realloc_count;
+        }
+    };
+
+    Stats* stats;
+
+    [[nodiscard]]
+    void* alloc(const asl::layout& layout) const
+    {
+        stats->alloc_count += 1;
+        stats->alive_bytes += layout.size;
+        return asl::GlobalHeap::alloc(layout);
+    }
+
+    void* realloc(void* ptr, const asl::layout& old, const asl::layout& new_layout) const
+    {
+        stats->realloc_count += 1;
+        stats->alive_bytes += new_layout.size - old.size;
+        return asl::GlobalHeap::realloc(ptr, old, new_layout);
+    }
+
+    void dealloc(void* ptr, const asl::layout& layout) const
+    {
+        stats->dealloc_count += 1;
+        stats->alive_bytes -= layout.size;
+        asl::GlobalHeap::dealloc(ptr, layout);
+    }
+
+    constexpr bool operator==(const CountingAllocator&) const { return true; }
+};
+static_assert(asl::allocator<CountingAllocator>);
--- a/asl/tests/types.hpp
+++ b/asl/tests/types.hpp
@ -77,7 +77,7 @@ struct DestructorObserver
    {
        if (this != &other)
        {
-            destroyed = asl::exchange(other.destroyed, nullptr);
+            asl::swap(destroyed, other.destroyed);
        }
        return *this;
    }
--- a/asl/types/BUILD.bazel
+++ b/asl/types/BUILD.bazel
@ -6,6 +6,18 @@ package(
    default_applicable_licenses = ["//:license"],
 )

+cc_library(
+    name = "array",
+    hdrs = [
+        "array.hpp",
+    ],
+    deps = [
+        "//asl/base",
+        "//asl/types:span",
+    ],
+    visibility = ["//visibility:public"],
+)
+
 cc_library(
    name = "box",
    hdrs = [
@ -14,6 +26,7 @@ cc_library(
    deps = [
        "//asl/base",
        "//asl/memory",
+        "//asl/memory:allocator",
        "//asl/hashing",
    ],
    visibility = ["//visibility:public"],
@ -86,6 +99,7 @@ cc_library(
    deps = [
        "//asl/base",
        "//asl/memory",
+        "//asl/memory:allocator",
    ],
    visibility = ["//visibility:public"],
 )
@ -97,6 +111,7 @@ cc_library(
    ],
    deps = [
        "//asl/base",
+        "//asl/memory",
    ],
    visibility = ["//visibility:public"],
 )
@ -121,6 +136,16 @@ cc_test(
    ],
 )

+cc_test(
+    name = "array_tests",
+    srcs = ["array_tests.cpp"],
+    deps = [
+        "//asl/tests:utils",
+        "//asl/testing",
+        "//asl/types:array",
+    ],
+)
+
 cc_test(
    name = "box_tests",
    srcs = ["box_tests.cpp"],
--- a/asl/types/array.hpp
+++ b/asl/types/array.hpp
@ -0,0 +1,70 @@
+// Copyright 2025 Steven Le Rouzic
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#pragma once
+
+#include "asl/base/assert.hpp"
+#include "asl/base/meta.hpp"
+#include "asl/base/utility.hpp"
+#include "asl/types/span.hpp"
+
+namespace asl
+{
+
+template<is_object T, isize_t kSize>
+requires (kSize > 0)
+struct array
+{
+    T m_data[kSize];
+
+    [[nodiscard]] constexpr bool is_empty() const { return false; }
+
+    [[nodiscard]] constexpr isize_t size() const { return kSize; }
+
+    constexpr auto data(this auto&& self)
+    {
+        using return_type = copy_const_t<un_ref_t<decltype(self)>, T>*;
+        return static_cast<return_type>(self.m_data);
+    }
+
+    constexpr auto begin(this auto&& self)
+    {
+        return contiguous_iterator{self.data()};
+    }
+
+    constexpr auto end(this auto&& self)
+    {
+        return contiguous_iterator{self.data() + kSize};
+    }
+
+    template<isize_t kSpanSize>
+    requires (kSpanSize == kSize || kSpanSize == dynamic_size)
+    constexpr operator span<const T, kSpanSize>() const // NOLINT(*explicit*)
+    {
+        return as_span();
+    }
+
+    template<isize_t kSpanSize>
+    requires (kSpanSize == kSize || kSpanSize == dynamic_size)
+    constexpr operator span<T, kSpanSize>() // NOLINT(*explicit*)
+    {
+        return as_span();
+    }
+
+    constexpr auto as_span(this auto&& self)
+    {
+        using type = copy_const_t<un_ref_t<decltype(self)>, T>;
+        return span<type, kSize>{self.data(), self.size()};
+    }
+
+    constexpr auto&& operator[](this auto&& self, isize_t i)
+    {
+        ASL_ASSERT(i >= 0 && i <= self.size());
+        return std::forward_like<decltype(self)>(std::forward<decltype(self)>(self).data()[i]);
+    }
+};
+
+
+} // namespace asl
+
--- a/asl/types/array_tests.cpp
+++ b/asl/types/array_tests.cpp
@ -0,0 +1,122 @@
+// Copyright 2025 Steven Le Rouzic
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#include "asl/types/array.hpp"
+
+#include "asl/testing/testing.hpp"
+#include "asl/tests/types.hpp"
+
+static_assert(sizeof(asl::array<int32_t, 8>) == 32);
+
+static_assert(asl::default_constructible<asl::array<int, 6>>);
+static_assert(asl::trivially_default_constructible<asl::array<int, 6>>);
+
+static_assert(asl::default_constructible<asl::array<TrivialType, 6>>);
+static_assert(asl::trivially_default_constructible<asl::array<TrivialType, 6>>);
+static_assert(asl::trivially_copy_constructible<asl::array<TrivialType, 6>>);
+static_assert(asl::trivially_copy_assignable<asl::array<TrivialType, 6>>);
+static_assert(asl::trivially_move_constructible<asl::array<TrivialType, 6>>);
+static_assert(asl::trivially_move_assignable<asl::array<TrivialType, 6>>);
+
+static_assert(asl::default_constructible<asl::array<TrivialTypeDefaultValue, 6>>);
+static_assert(!asl::trivially_default_constructible<asl::array<TrivialTypeDefaultValue, 6>>);
+
+static_assert(asl::trivially_destructible<asl::array<int, 6>>);
+static_assert(asl::trivially_destructible<asl::array<TrivialType, 6>>);
+static_assert(!asl::trivially_destructible<asl::array<WithDestructor, 6>>);
+
+static_assert(asl::copyable<asl::array<Copyable, 6>>);
+static_assert(!asl::copyable<asl::array<MoveableOnly, 6>>);
+static_assert(!asl::copyable<asl::array<Pinned, 6>>);
+
+static_assert(asl::moveable<asl::array<Copyable, 6>>);
+static_assert(asl::moveable<asl::array<MoveableOnly, 6>>);
+static_assert(!asl::moveable<asl::array<Pinned, 6>>);
+
+ASL_TEST(construct_default)
+{
+    asl::array<int, 4> arr{};
+
+    ASL_TEST_EXPECT(static_cast<void*>(&arr) == static_cast<void*>(arr.data()));
+
+    ASL_TEST_EXPECT(arr[0] == 0);
+    ASL_TEST_EXPECT(arr[1] == 0);
+    ASL_TEST_EXPECT(arr[2] == 0);
+    ASL_TEST_EXPECT(arr[3] == 0);
+
+    ASL_TEST_EXPECT(arr.data()[0] == 0); // NOLINT
+    ASL_TEST_EXPECT(arr.data()[1] == 0); // NOLINT
+    ASL_TEST_EXPECT(arr.data()[2] == 0); // NOLINT
+    ASL_TEST_EXPECT(arr.data()[3] == 0); // NOLINT
+}
+
+ASL_TEST(construct)
+{
+    asl::array<int, 4> arr{10, 11, 12, 13};
+
+    ASL_TEST_EXPECT(arr[0] == 10);
+    ASL_TEST_EXPECT(arr[1] == 11);
+    ASL_TEST_EXPECT(arr[2] == 12);
+    ASL_TEST_EXPECT(arr[3] == 13);
+
+    ASL_TEST_EXPECT(arr.data()[0] == 10); // NOLINT
+    ASL_TEST_EXPECT(arr.data()[1] == 11); // NOLINT
+    ASL_TEST_EXPECT(arr.data()[2] == 12); // NOLINT
+    ASL_TEST_EXPECT(arr.data()[3] == 13); // NOLINT
+}
+
+static_assert(asl::convertible_to<asl::array<int, 4>, asl::span<int, 4>>);
+static_assert(asl::convertible_to<asl::array<int, 4>, asl::span<int>>);
+
+ASL_TEST(sized_span)
+{
+    asl::array<int, 4> arr{10, 11, 12, 13};
+    const asl::span<int, 4> s1 = arr;
+
+    ASL_TEST_EXPECT(s1.size() == 4);
+    ASL_TEST_EXPECT(s1.data() == arr.data());
+    ASL_TEST_EXPECT(s1[0] == 10);
+    ASL_TEST_EXPECT(s1[1] == 11);
+    ASL_TEST_EXPECT(s1[2] == 12);
+    ASL_TEST_EXPECT(s1[3] == 13);
+}
+
+ASL_TEST(unsized_span)
+{
+    asl::array<int, 4> arr{10, 11, 12, 13};
+    const asl::span<int> s2 = arr;
+
+    ASL_TEST_EXPECT(s2.size() == 4);
+    ASL_TEST_EXPECT(s2[0] == 10);
+    ASL_TEST_EXPECT(s2[1] == 11);
+    ASL_TEST_EXPECT(s2[2] == 12);
+    ASL_TEST_EXPECT(s2[3] == 13);
+}
+
+ASL_TEST(iterator)
+{
+    const asl::array<int, 4> arr{10, 11, 12, 13};
+
+    auto it = arr.begin();
+    auto end = arr.end();
+
+    ASL_TEST_ASSERT(it != end);
+    ASL_TEST_EXPECT(*it == 10);
+    it++;
+
+    ASL_TEST_ASSERT(it != end);
+    ASL_TEST_EXPECT(*it == 11);
+    it++;
+
+    ASL_TEST_ASSERT(it != end);
+    ASL_TEST_EXPECT(*it == 12);
+    it++;
+
+    ASL_TEST_ASSERT(it != end);
+    ASL_TEST_EXPECT(*it == 13);
+    it++;
+
+    ASL_TEST_ASSERT(it == end);
+}
+
--- a/asl/types/function_ref.hpp
+++ b/asl/types/function_ref.hpp
@ -7,6 +7,7 @@
 #include "asl/base/utility.hpp"
 #include "asl/base/meta.hpp"
 #include "asl/base/functional.hpp"
+#include "asl/memory/memory.hpp"

 namespace asl
 {
@ -43,7 +44,7 @@ public:
            && same_as<invoke_result_t<T, Args...>, R>
        )
        // NOLINTNEXTLINE(*cast*)
-        : m_obj{const_cast<void*>(reinterpret_cast<const void*>(&t))}
+        : m_obj{const_cast<void*>(reinterpret_cast<const void*>(address_of(t)))}
        , m_invoke{invoke<un_ref_t<T>>}
    {}

@ -56,7 +57,7 @@ public:
        )
    {
        // NOLINTNEXTLINE(*cast*)
-        m_obj = const_cast<void*>(reinterpret_cast<const void*>(&t));
+        m_obj = const_cast<void*>(reinterpret_cast<const void*>(address_of(t)));
        m_invoke = invoke<un_ref_t<T>>;

        return *this;
--- a/asl/types/maybe_uninit_tests.cpp
+++ b/asl/types/maybe_uninit_tests.cpp
@ -10,6 +10,8 @@ static_assert(asl::size_of<int> == asl::size_of<asl::maybe_uninit<int>>);
 static_assert(asl::align_of<int> == asl::align_of<asl::maybe_uninit<int>>);

 #define TEST_TYPE_PROPERTIES(PRP) \
+    static_assert(asl::PRP<asl::maybe_uninit<int>> == asl::PRP<int>); \
+    static_assert(asl::PRP<asl::maybe_uninit<void*>> == asl::PRP<void*>); \
    static_assert(asl::PRP<asl::maybe_uninit<TrivialType>> == asl::PRP<TrivialType>); \
    static_assert(asl::PRP<asl::maybe_uninit<TrivialTypeDefaultValue>> == asl::PRP<TrivialTypeDefaultValue>); \
    static_assert(asl::PRP<asl::maybe_uninit<WithDestructor>> == asl::PRP<WithDestructor>); \
@ -17,6 +19,8 @@ static_assert(asl::align_of<int> == asl::align_of<asl::maybe_uninit<int>>);
    static_assert(asl::PRP<asl::maybe_uninit<MoveableOnly>> == asl::PRP<MoveableOnly>); \
    static_assert(asl::PRP<asl::maybe_uninit<Pinned>> == asl::PRP<Pinned>);

+// @Todo(C++26) We expect this to break once trivial unions land.
+// https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2025/p3074r7.html#just-make-it-work
 TEST_TYPE_PROPERTIES(trivially_default_constructible);
 TEST_TYPE_PROPERTIES(trivially_copy_constructible);
 TEST_TYPE_PROPERTIES(trivially_move_constructible);
--- a/asl/types/span.hpp
+++ b/asl/types/span.hpp
@ -68,7 +68,7 @@ public:
        , m_size{size}
    {}

-    constexpr explicit span(T* data, isize_t size)
+    constexpr explicit span(T* data, [[maybe_unused]] isize_t size)
        requires (!kIsDynamic)
        : m_data{data}
    {
--- a/bazel/clang_toolchain/BUILD.bazel
+++ b/bazel/clang_toolchain/BUILD.bazel
@ -0,0 +1,4 @@
+# Copyright 2025 Steven Le Rouzic
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
--- a/bazel/clang_toolchain/clang_config.bzl.tpl
+++ b/bazel/clang_toolchain/clang_config.bzl.tpl
@ -0,0 +1,8 @@
+# Copyright 2025 Steven Le Rouzic
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+CLANG_BINDIR = "{CLANG_BINDIR}"
+CLANG_LIBDIR = "{CLANG_LIBDIR}"
+CLANG_INCLUDE_DIRS = {CLANG_INCLUDE_DIRS}
+
--- a/bazel/clang_toolchain/clang_toolchain.BUILD.bazel
+++ b/bazel/clang_toolchain/clang_toolchain.BUILD.bazel
@ -0,0 +1,19 @@
+# Copyright 2025 Steven Le Rouzic
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+load(":toolchain_config.bzl", "declare_toolchain")
+
+filegroup(name = "empty")
+
+PAIRS = [
+    ("windows", "x86_64"),
+    ("linux",   "x86_64"),
+    ("linux",   "aarch64"),
+]
+
+[
+    declare_toolchain(name = "%s_%s_toolchain" % (os, arch), os = os, arch = arch)
+    for (os, arch) in PAIRS
+]
+
--- a/bazel/clang_toolchain/config_detection.bzl
+++ b/bazel/clang_toolchain/config_detection.bzl
@ -0,0 +1,113 @@
+# Copyright 2025 Steven Le Rouzic
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+def _copy_file(ctx, from_path, to_path):
+    content = ctx.read(from_path)
+    ctx.file(to_path, content = content)
+
+def _get_clang_info(ctx, clang_path, line_prefix):
+    result = ctx.execute([clang_path, "--version"])
+    if result.return_code != 0:
+        return None
+
+    for l in result.stdout.splitlines():
+        if l.startswith(line_prefix):
+            l = l[len(line_prefix):]
+            return l.split(" ")[0]
+
+    return None
+
+def _get_clang_version(ctx, clang_path):
+    return _get_clang_info(ctx, clang_path, "clang version ")
+
+def _get_clang_lib_dir(ctx, clang_path):
+    result = ctx.execute([clang_path, "-no-canonical-prefixes", "--print-resource-dir"])
+    if result.return_code != 0:
+        return None
+
+    return result.stdout
+
+def _get_include_dirs(ctx, clang_path):
+    ctx.file("detect.cpp", content = "")
+    detect_path = ctx.path("detect.cpp")
+    res = ctx.execute([
+        clang_path,
+        "-v",
+        "-no-canonical-prefixes",
+        "-fsyntax-only",
+        "-x", "c++",
+        detect_path,
+    ])
+
+    lines = res.stderr.splitlines()
+    listing_include_dirs = False
+    include_dirs = []
+
+    for l in lines:
+        if l.startswith("#include <...> search starts here:"):
+            listing_include_dirs = True
+        elif l.startswith("End of search list."):
+            listing_include_dirs = False
+        elif listing_include_dirs:
+            include_dirs.append(l.strip())
+
+    return include_dirs
+
+def _impl(ctx):
+    _copy_file(ctx, ctx.attr._build_bazel, "BUILD.bazel")
+    _copy_file(ctx, ctx.attr._toolchain_config_bzl, "toolchain_config.bzl")
+
+    clang_path = ctx.which("clang")
+    if not clang_path:
+        fail("Could not find clang")
+
+    clang_version = _get_clang_version(ctx, clang_path)
+    if not clang_version:
+        fail("Could not detect clang version")
+
+    clang_lib_dir = _get_clang_lib_dir(ctx, clang_path)
+    if not clang_lib_dir:
+        fail("Could not detect clang lib dir")
+
+    include_dirs = _get_include_dirs(ctx, clang_path)
+    if not include_dirs:
+        fail("Could not detect include dirs")
+
+    ctx.template(
+        "clang_config.bzl",
+        ctx.attr._clang_config_bzl_tpl,
+        executable = False,
+        substitutions = {
+            "{CLANG_BINDIR}": str(clang_path.dirname),
+            "{CLANG_LIBDIR}": str(clang_lib_dir).strip().replace("\\", "/"),
+            "{CLANG_INCLUDE_DIRS}": str(include_dirs),
+        },
+    )
+
+
+_config_detection = repository_rule(
+    implementation = _impl,
+    local = True,
+    configure = True,
+    attrs = {
+        "_build_bazel": attr.label(
+            default = Label("//bazel/clang_toolchain:clang_toolchain.BUILD.bazel"),
+            allow_single_file = True,
+        ),
+        "_toolchain_config_bzl": attr.label(
+            default = Label("//bazel/clang_toolchain:toolchain_config.bzl"),
+            allow_single_file = True,
+        ),
+        "_clang_config_bzl_tpl": attr.label(
+            default = Label("//bazel/clang_toolchain:clang_config.bzl.tpl"),
+            allow_single_file = True,
+        ),
+    },
+)
+
+clang_toolchain = module_extension(
+    implementation = lambda ctx: _config_detection(
+        name = "clang_toolchain",
+    ),
+)
--- a/bazel/clang_toolchain/toolchain_config.bzl
+++ b/bazel/clang_toolchain/toolchain_config.bzl
@ -0,0 +1,596 @@
+# Copyright 2025 Steven Le Rouzic
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+load(
+    "//:clang_config.bzl",
+    "CLANG_BINDIR",
+    "CLANG_LIBDIR",
+    "CLANG_INCLUDE_DIRS",
+)
+
+load("@rules_cc//cc:action_names.bzl", "ACTION_NAMES")
+
+load(
+    "@rules_cc//cc:cc_toolchain_config_lib.bzl",
+    "action_config",
+    "artifact_name_pattern",
+    "feature",
+    "feature_set",
+    "flag_group",
+    "flag_set",
+    "tool",
+    "tool_path",
+    "variable_with_value",
+)
+
+CPP_COMPILE_ACTIONS = [
+    ACTION_NAMES.cpp_compile,
+    ACTION_NAMES.cpp_header_parsing
+]
+
+C_COMPILE_ACTIONS = [
+    ACTION_NAMES.c_compile,
+]
+
+COMPILE_ACTIONS = C_COMPILE_ACTIONS + CPP_COMPILE_ACTIONS
+
+LINK_ACTIONS = [
+    ACTION_NAMES.cpp_link_dynamic_library,
+    ACTION_NAMES.cpp_link_nodeps_dynamic_library,
+    ACTION_NAMES.cpp_link_executable,
+]
+
+ARCHIVE_ACTIONS = [
+    ACTION_NAMES.cpp_link_static_library,
+]
+
+def _impl(ctx):
+    os = ctx.attr.os
+    is_windows = os == "windows"
+    exe_suffix = ".exe" if is_windows else ""
+
+    tool_paths = [
+        tool_path(name = "ar",      path = CLANG_BINDIR + "/llvm-ar" + exe_suffix),
+        tool_path(name = "ld",      path = CLANG_BINDIR + "/ld.lld" + exe_suffix),
+        tool_path(name = "nm",      path = CLANG_BINDIR + "/llvm-nm" + exe_suffix),
+        tool_path(name = "objdump", path = CLANG_BINDIR + "/llvm-objdump" + exe_suffix),
+        tool_path(name = "strip",   path = CLANG_BINDIR + "/llvm-strip" + exe_suffix),
+        tool_path(name = "gcc",     path = CLANG_BINDIR + "/clang" + exe_suffix),
+        tool_path(name = "cpp",     path = CLANG_BINDIR + "/clang++" + exe_suffix),
+    ]
+
+    action_configs = [
+        action_config(action_name = name, enabled = True, tools = [tool(path = CLANG_BINDIR + "/clang" + exe_suffix)])
+        for name in C_COMPILE_ACTIONS
+    ] + [
+        action_config(action_name = name, enabled = True, tools = [tool(path = CLANG_BINDIR + "/clang++" + exe_suffix)])
+        for name in CPP_COMPILE_ACTIONS
+    ] + [
+        action_config(action_name = name, enabled = True, tools = [tool(path = CLANG_BINDIR + "/clang++" + exe_suffix)])
+        for name in LINK_ACTIONS
+    ] + [
+        action_config(action_name = name, enabled = True, tools = [tool(path = CLANG_BINDIR + "/llvm-ar" + exe_suffix)])
+        for name in ARCHIVE_ACTIONS
+    ] + [
+        action_config(ACTION_NAMES.strip, enabled = True, tools = [tool(path = CLANG_BINDIR + "/llvm-strip" + exe_suffix)]),
+    ]
+
+    artifact_name_patterns = [
+        artifact_name_pattern(
+            category_name = "object_file",
+            prefix = "",
+            extension = ".obj" if is_windows else ".o",
+        ),
+        artifact_name_pattern(
+            category_name = "static_library",
+            prefix = "" if is_windows else "lib",
+            extension = ".lib" if is_windows else ".a",
+        ),
+        artifact_name_pattern(
+            category_name = "dynamic_library",
+            prefix = "" if is_windows else "lib",
+            extension = ".dll" if is_windows else ".so",
+        ),
+        artifact_name_pattern(
+            category_name = "executable",
+            prefix = "",
+            extension = exe_suffix,
+        ),
+    ]
+
+    asan_link_flag_sets = []
+    ubsan_link_flag_sets = []
+
+    if is_windows:
+        asan_link_flag_sets.append(flag_set(
+            actions = LINK_ACTIONS,
+            flag_groups = [
+                flag_group(
+                    flags = [
+                        "-l\"" + CLANG_LIBDIR + "/lib/windows/clang_rt.asan_dynamic-x86_64.lib\"",
+                    ],
+                ),
+            ],
+        ))
+
+        ubsan_link_flag_sets.append(flag_set(
+            actions = LINK_ACTIONS,
+            flag_groups = [
+                flag_group(
+                    flags = [
+                        "-l\"" + CLANG_LIBDIR + "/lib/windows/clang_rt.ubsan_standalone-x86_64.lib\"",
+                    ],
+                ),
+            ],
+        ))
+
+    features = [
+        feature(name = "no_legacy_features"),
+        feature(name = "opt"),
+        feature(name = "fastbuild"),
+        feature(name = "dbg"),
+        feature(
+            name = "default_flags",
+            enabled = True,
+            flag_sets = [
+                flag_set(
+                    actions = COMPILE_ACTIONS + LINK_ACTIONS,
+                    flag_groups = [
+                        flag_group(
+                            flags = [
+                                "-no-canonical-prefixes",
+                                "-fcolor-diagnostics",
+                            ],
+                        ),
+                    ],
+                ),
+                flag_set(
+                    actions = LINK_ACTIONS,
+                    flag_groups = [
+                        flag_group(
+                            flags = [
+                                "-fuse-ld=lld",
+                            ],
+                        ),
+                    ],
+                ),
+                flag_set(
+                    actions = COMPILE_ACTIONS,
+                    flag_groups = [
+                        flag_group(
+                            flags = [
+                                "-Wno-builtin-macro-redefined",
+                                "-D__DATE__=\"redacted\"",
+                                "-D__TIMESTAMP__=\"redacted\"",
+                                "-D__TIME__=\"redacted\"",
+                                "-c",
+                            ],
+                        ),
+                        flag_group(
+                            flags = ["-frandom-seed=%{output_file}"],
+                            expand_if_available = "output_file",
+                        ),
+                        flag_group(
+                            flags = ["-D%{preprocessor_defines}"],
+                            iterate_over = "preprocessor_defines",
+                        ),
+                        flag_group(
+                            flags = ["-I%{include_paths}"],
+                            iterate_over = "include_paths",
+                        ),
+                        flag_group(
+                            flags = ["-iquote", "%{quote_include_paths}"],
+                            iterate_over = "quote_include_paths",
+                        ),
+                        flag_group(
+                            flags = ["-isystem", "%{system_include_paths}"],
+                            iterate_over = "system_include_paths",
+                        ),
+                        flag_group(
+                            flags = ["-MD", "-MF", "%{dependency_file}"],
+                            expand_if_available = "dependency_file",
+                        ),
+                    ],
+                ),
+                flag_set(
+                    actions = ARCHIVE_ACTIONS,
+                    flag_groups = [
+                        flag_group(
+                            flags = ["rcsD"],
+                        ),
+                        flag_group(
+                            flags = ["%{output_execpath}"],
+                            expand_if_available = "output_execpath",
+                        ),
+                    ],
+                ),
+                flag_set(
+                    actions = LINK_ACTIONS + ARCHIVE_ACTIONS,
+                    flag_groups = [
+                        flag_group(
+                            iterate_over = "libraries_to_link",
+                            expand_if_available = "libraries_to_link",
+                            flag_groups = [
+                                flag_group(
+                                    flags = ["-Wl,--start-lib"],
+                                    expand_if_equal = variable_with_value(
+                                        name = "libraries_to_link.type",
+                                        value = "object_file_group",
+                                    ),
+                                ),
+                                flag_group(
+                                    iterate_over = "libraries_to_link.object_files",
+                                    expand_if_equal = variable_with_value(
+                                        name = "libraries_to_link.type",
+                                        value = "object_file_group",
+                                    ),
+                                    flag_groups = [
+                                        flag_group(
+                                            flags = ["%{libraries_to_link.object_files}"],
+                                            expand_if_false = "libraries_to_link.is_whole_archive",
+                                        ),
+                                        flag_group(
+                                            flags = ["-Wl,-force_load,%{libraries_to_link.object_files}"],
+                                            expand_if_true = "libraries_to_link.is_whole_archive",
+                                        ),
+                                    ],
+                                ),
+                                flag_group(
+                                    expand_if_equal = variable_with_value(
+                                        name = "libraries_to_link.type",
+                                        value = "object_file",
+                                    ),
+                                    flag_groups = [
+                                        flag_group(
+                                            flags = ["%{libraries_to_link.name}"],
+                                            expand_if_false = "libraries_to_link.is_whole_archive",
+                                        ),
+                                        flag_group(
+                                            flags = ["-Wl,-force_load,%{libraries_to_link.name}"],
+                                            expand_if_true = "libraries_to_link.is_whole_archive",
+                                        ),
+                                    ],
+                                ),
+                                flag_group(
+                                    expand_if_equal = variable_with_value(
+                                        name = "libraries_to_link.type",
+                                        value = "interface_library",
+                                    ),
+                                    flag_groups = [
+                                        flag_group(
+                                            flags = ["%{libraries_to_link.name}"],
+                                            expand_if_false = "libraries_to_link.is_whole_archive",
+                                        ),
+                                        flag_group(
+                                            flags = ["-Wl,-force_load,%{libraries_to_link.name}"],
+                                            expand_if_true = "libraries_to_link.is_whole_archive",
+                                        ),
+                                    ],
+                                ),
+                                flag_group(
+                                    expand_if_equal = variable_with_value(
+                                        name = "libraries_to_link.type",
+                                        value = "static_library",
+                                    ),
+                                    flag_groups = [
+                                        flag_group(
+                                            flags = ["%{libraries_to_link.name}"],
+                                            expand_if_false = "libraries_to_link.is_whole_archive",
+                                        ),
+                                        flag_group(
+                                            flags = ["-Wl,-force_load,%{libraries_to_link.name}"],
+                                            expand_if_true = "libraries_to_link.is_whole_archive",
+                                        ),
+                                    ],
+                                ),
+                                flag_group(
+                                    flags = ["-l%{libraries_to_link.name}"],
+                                    expand_if_equal = variable_with_value(
+                                        name = "libraries_to_link.type",
+                                        value = "dynamic_library",
+                                    ),
+                                ),
+                                flag_group(
+                                    flags = ["-l:%{libraries_to_link.name}"],
+                                    expand_if_equal = variable_with_value(
+                                        name = "libraries_to_link.type",
+                                        value = "versioned_dynamic_library",
+                                    ),
+                                ),
+                                flag_group(
+                                    expand_if_true = "libraries_to_link.is_whole_archive",
+                                    flag_groups = [
+                                        flag_group(
+                                            expand_if_false = "macos_flags",
+                                            flags = ["-Wl,-no-whole-archive"],
+                                        ),
+                                    ],
+                                ),
+                                flag_group(
+                                    flags = ["-Wl,--end-lib"],
+                                    expand_if_equal = variable_with_value(
+                                        name = "libraries_to_link.type",
+                                        value = "object_file_group",
+                                    ),
+                                ),
+                            ],
+                        ),
+                    ],
+                ),
+            ],
+        ),
+        feature(
+            name = "windows_linker_flags",
+            enabled = is_windows,
+            flag_sets = [
+                flag_set(
+                    actions = LINK_ACTIONS,
+                    flag_groups = [
+                        flag_group(
+                            flags = [
+                                "-Xlinker",
+                                "/subsystem:console",
+                            ],
+                        ),
+                    ],
+                ),
+            ],
+        ),
+        feature(
+            name = "dbg_flags",
+            enabled = True,
+            requires = [feature_set(["dbg"])],
+            flag_sets = [
+                flag_set(
+                    actions = COMPILE_ACTIONS,
+                    flag_groups = [
+                        flag_group(
+                            flags = [
+                                "-DDEBUG=1",
+                            ],
+                        ),
+                    ],
+                ),
+                flag_set(
+                    actions = COMPILE_ACTIONS + LINK_ACTIONS,
+                    flag_groups = [
+                        flag_group(
+                            flags = [
+                                "-g3",
+                            ],
+                        ),
+                    ],
+                ),
+            ],
+        ),
+        feature(
+            name = "fastbuild_flags",
+            enabled = True,
+            requires = [feature_set(["fastbuild"])],
+            flag_sets = [
+                flag_set(
+                    actions = COMPILE_ACTIONS,
+                    flag_groups = [
+                        flag_group(
+                            flags = [
+                                "-O1",
+                                "-DDEBUG=1",
+                            ],
+                        ),
+                    ],
+                ),
+                flag_set(
+                    actions = COMPILE_ACTIONS + LINK_ACTIONS,
+                    flag_groups = [
+                        flag_group(
+                            flags = [
+                                "-g1",
+                            ],
+                        ),
+                    ],
+                ),
+            ],
+        ),
+        feature(
+            name = "opt_flags",
+            enabled = True,
+            requires = [feature_set(["opt"])],
+            flag_sets = [
+                flag_set(
+                    actions = COMPILE_ACTIONS,
+                    flag_groups = [
+                        flag_group(
+                            flags = [
+                                "-O3",
+                                "-DNDEBUG=1",
+                            ],
+                        ),
+                    ],
+                ),
+            ],
+        ),
+        feature(
+            name = "c++20",
+            provides = ["c++_version"],
+            flag_sets = [
+                flag_set(
+                    actions = COMPILE_ACTIONS,
+                    flag_groups = [
+                        flag_group(
+                            flags = ["-std=c++20"],
+                        ),
+                    ],
+                ),
+            ],
+        ),
+        feature(
+            name = "c++23",
+            provides = ["c++_version"],
+            flag_sets = [
+                flag_set(
+                    actions = COMPILE_ACTIONS,
+                    flag_groups = [
+                        flag_group(
+                            flags = ["-std=c++23"],
+                        ),
+                    ],
+                ),
+            ],
+        ),
+        feature(
+            name = "asan",
+            implies = ["sanitize"],
+            flag_sets = [
+                flag_set(
+                    actions = COMPILE_ACTIONS + LINK_ACTIONS,
+                    flag_groups = [
+                        flag_group(
+                            flags = [
+                                "-fsanitize=address",
+                            ],
+                        ),
+                    ],
+                ),
+            ] + asan_link_flag_sets,
+        ),
+        feature(
+            name = "ubsan",
+            implies = ["sanitize"],
+            flag_sets = [
+                flag_set(
+                    actions = COMPILE_ACTIONS + LINK_ACTIONS,
+                    flag_groups = [
+                        flag_group(
+                            flags = [
+                                "-fsanitize=undefined",
+                            ],
+                        ),
+                    ],
+                ),
+            ] + ubsan_link_flag_sets,
+        ),
+        feature(
+            name = "sanitize",
+            flag_sets = [
+                flag_set(
+                    actions = COMPILE_ACTIONS,
+                    flag_groups = [
+                        flag_group(
+                            flags = [
+                                "-fno-omit-frame-pointer",
+                                "-fno-sanitize-ignorelist",
+                                "-fno-sanitize-recover=all",
+                            ],
+                        ),
+                    ],
+                ),
+            ],
+        ),
+        feature(
+            name = "final_flags",
+            enabled = True,
+            flag_sets = [
+                flag_set(
+                    actions = COMPILE_ACTIONS,
+                    flag_groups = [
+                        flag_group(
+                            flags = ["%{user_compile_flags}"],
+                            expand_if_available = "user_compile_flags",
+                            iterate_over = "user_compile_flags",
+                        ),
+                        flag_group(
+                            flags = ["-o", "%{output_file}"],
+                            expand_if_available = "output_file",
+                        ),
+                        flag_group(
+                            flags = ["%{source_file}"],
+                            expand_if_available = "source_file",
+                        ),
+                    ],
+                ),
+                flag_set(
+                    actions = LINK_ACTIONS,
+                    flag_groups = [
+                        flag_group(
+                            flags = ["%{user_link_flags}"],
+                            expand_if_available = "user_link_flags",
+                            iterate_over = "user_link_flags",
+                        ),
+                        flag_group(
+                            flags = ["-o", "%{output_execpath}"],
+                            expand_if_available = "output_execpath",
+                        ),
+                    ],
+                ),
+                flag_set(
+                    actions = LINK_ACTIONS + ARCHIVE_ACTIONS,
+                    flag_groups = [
+                        flag_group(
+                            flags = ["@%{linker_param_file}"],
+                            expand_if_available = "linker_param_file",
+                        ),
+                    ],
+                ),
+            ],
+        ),
+    ]
+
+    return cc_common.create_cc_toolchain_config_info(
+        ctx = ctx,
+        toolchain_identifier = "%s-toolchain" % os,
+        compiler = "clang",
+        artifact_name_patterns = artifact_name_patterns,
+        cxx_builtin_include_directories = CLANG_INCLUDE_DIRS,
+        tool_paths = tool_paths,
+        action_configs = action_configs,
+        features = features,
+    )
+
+toolchain_config = rule(
+    implementation = _impl,
+    attrs = {
+        "os": attr.string(mandatory = True),
+    },
+    provides = [CcToolchainConfigInfo],
+)
+
+def _declare_toolchain_impl(name, os, arch, visibility):
+    toolchain_config(
+        name = name + "_config",
+        os = os,
+    )
+
+    native.cc_toolchain(
+        name = name + "_cc",
+        toolchain_config = name + "_config",
+        all_files = ":empty",
+        compiler_files = ":empty",
+        linker_files = ":empty",
+        objcopy_files = ":empty",
+        strip_files = ":empty",
+        dwp_files = ":empty",
+    )
+
+    native.toolchain(
+        name = name + "_def",
+        toolchain = name + "_cc",
+        toolchain_type = "@rules_cc//cc:toolchain_type",
+        exec_compatible_with = [
+            "@platforms//cpu:%s" % arch,
+            "@platforms//os:%s" % os,
+        ],
+        target_compatible_with = [
+            "@platforms//cpu:%s" % arch,
+            "@platforms//os:%s" % os,
+        ],
+        visibility = ["//visibility:public"],
+    )
+
+declare_toolchain = macro(
+    implementation = _declare_toolchain_impl,
+    attrs = {
+        "os":   attr.string(mandatory = True, configurable = False),
+        "arch": attr.string(mandatory = True, configurable = False),
+    }
+)
--- a/refresh_clangd.sh
+++ b/refresh_clangd.sh
@ -1 +1 @@
-bazel run //tools:refresh_clangd --config=linux -- --config=linux
+bazel run //tools:refresh_clangd
--- a/todo.txt
+++ b/todo.txt
@ -1 +1,6 @@
+constexpr cast from void* +cpp26 https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2023/p2738r1.pdf
+
+add sanitizers features +bazel_clang_toolchain
+linux x64 support +bazel_clang_toolchain
+linux arm64 support +bazel_clang_toolchain

--- a/tools/fix_line_endings.py
+++ b/tools/fix_line_endings.py
@ -19,6 +19,7 @@ TO_FIX = [
    "**/*.cpp",
    "**/*.py",
    "**/*.bzl",
+    "**/*.bzl.tpl",
    "**/*.bazel",
    "**/*.txt",
    "**/*.bat",
--- a/vendor/dragonbox/BUILD.bazel
+++ b/vendor/dragonbox/BUILD.bazel
@ -18,7 +18,7 @@ cc_library(
    name = "dragonbox",
    hdrs = ["dragonbox.h"],
    includes = ["."],
-    visibility = ["//:__subpackages__"],
+    visibility = ["//asl:__subpackages__"],
    applicable_licenses = [
        ":license",
    ],
--- a/vendor/fast_float/BUILD.bazel
+++ b/vendor/fast_float/BUILD.bazel
@ -0,0 +1,25 @@
+# Copyright 2025 Steven Le Rouzic
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+load("@rules_license//rules:license.bzl", "license")
+
+license(
+    name = "license",
+    license_kinds = [
+        "@rules_license//licenses/spdx:MIT",
+    ],
+    license_text = "LICENSE.txt",
+    package_name = "fast_float",
+    package_url = "https://github.com/fastfloat/fast_float",
+)
+
+cc_library(
+    name = "fast_float",
+    hdrs = ["fast_float.h"],
+    includes = ["."],
+    visibility = ["//asl:__subpackages__"],
+    applicable_licenses = [
+        ":license",
+    ],
+)
--- a/vendor/fast_float/LICENSE.txt
+++ b/vendor/fast_float/LICENSE.txt
@ -0,0 +1,27 @@
+MIT License
+
+Copyright (c) 2021 The fast_float authors
+
+Permission is hereby granted, free of charge, to any
+person obtaining a copy of this software and associated
+documentation files (the "Software"), to deal in the
+Software without restriction, including without
+limitation the rights to use, copy, modify, merge,
+publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software
+is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice
+shall be included in all copies or substantial portions
+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
--- a/vendor/fast_float/fast_float.h
+++ b/vendor/fast_float/fast_float.h
Author	SHA1	Message	Date
Steven Le Rouzic	9f792e536b	Implement Bazel Clang toolchain	2025-07-12 17:11:54 +02:00
Steven Le Rouzic	00ea14788f	Fix a bunch of warnings	2025-07-06 17:05:36 +02:00
Steven Le Rouzic	bcdad5b876	Add numbers parsing	2025-07-04 20:44:04 +02:00
Steven Le Rouzic	cca2e26724	Add integer traits	2025-07-04 18:22:03 +02:00
Steven Le Rouzic	195f20ff17	Add SparseHandlePool	2025-07-03 18:35:25 +02:00
Steven Le Rouzic	a78e24e9eb	Add DenseHandlePool	2025-07-03 18:34:45 +02:00
Steven Le Rouzic	43ab95880d	Add pop method to chunked_buffer	2025-06-26 18:25:00 +02:00
Steven Le Rouzic	47c6677405	Add IndexPool	2025-06-26 12:37:02 +02:00
Steven Le Rouzic	92f908ee1b	Add index_pool_handle	2025-06-18 00:05:33 +02:00
Steven Le Rouzic	30237bb78f	Add index_pool_config	2025-06-18 00:05:33 +02:00
Steven Le Rouzic	8f59f113e8	Fix test execution after a fail	2025-06-18 00:05:33 +02:00
Steven Le Rouzic	afb237c513	Add smallest_unsigned_integer_type_for_width	2025-06-14 12:56:11 +02:00
Steven Le Rouzic	19e2164441	Use the new Bazel registry	2025-06-04 21:59:48 +02:00
Steven Le Rouzic	b8a87223bb	Add compile-time configuration for build settings	2025-05-26 22:38:04 +02:00
Steven Le Rouzic	a1db1cd9e2	Implement chunked_buffer	2025-05-26 00:48:06 +02:00
Steven Le Rouzic	54b95b1662	Buffer type has to be moveable, always	2025-05-17 23:01:51 +02:00
Steven Le Rouzic	e7e7023340	Fix build on Linux	2025-05-16 22:59:09 +02:00
Steven Le Rouzic	f7a2699ac0	Add and use copy_const_t	2025-05-14 00:41:51 +02:00
Steven Le Rouzic	088e03708a	Add array	2025-05-14 00:41:51 +02:00
Steven Le Rouzic	5bca42b049	Version 0.4.0	2025-05-08 00:16:26 +02:00
Steven Le Rouzic	e1ba7dd7a9	Add enum underlying utilities	2025-05-08 00:15:26 +02:00
Steven Le Rouzic	837f696971	Update some Bazel rules	2025-04-11 19:57:37 +02:00
Steven Le Rouzic	afbfd0e781	Add numeric library	2025-04-03 23:27:39 +02:00
Steven Le Rouzic	0776012d09	Add bit library	2025-04-03 00:34:54 +02:00
Steven Le Rouzic	4f8cbd442a	Add invoke_r & co	2025-03-26 21:52:00 +01:00
Steven Le Rouzic	2d309a2cff	Separate allocator from memory	2025-03-26 21:35:18 +01:00
Steven Le Rouzic	f19d93a69a	Improve implementation of invoke	2025-03-26 18:54:54 +01:00
Steven Le Rouzic	e034efe8bd	Add member pointer stuff to meta lib	2025-03-26 18:54:53 +01:00
Steven Le Rouzic	2c457c4275	Add address_of	2025-03-26 18:54:49 +01:00