From 46944ec98688e962e94dcfcf426215f252bf2a87 Mon Sep 17 00:00:00 2001
From: Steven Le Rouzic <steven.lerouzic@gmail.com>
Date: Fri, 3 Jan 2025 12:13:34 +0100
Subject: Start work on status

---
 asl/allocator.hpp            | 27 +++++++++++++++++
 asl/integers.hpp             |  2 ++
 asl/status.cpp               | 27 +++++++++++++++++
 asl/status.hpp               | 69 ++++++++++++++++++++++++++++++++++++++++++++
 asl/tests/integers_tests.cpp |  2 ++
 asl/tests/status_tests.cpp   | 27 +++++++++++++++++
 asl/utility.hpp              |  8 +++++
 7 files changed, 162 insertions(+)

(limited to 'asl')

diff --git a/asl/allocator.hpp b/asl/allocator.hpp
index 5f8f9b6..265378b 100644
--- a/asl/allocator.hpp
+++ b/asl/allocator.hpp
@@ -2,6 +2,7 @@
 
 #include "asl/layout.hpp"
 #include "asl/meta.hpp"
+#include "asl/memory.hpp"
 
 namespace asl
 {
@@ -28,4 +29,30 @@ static_assert(allocator<GlobalHeap>);
 
 using DefaultAllocator = GlobalHeap;
 
+template<typename T>
+T* alloc_new(allocator auto& a, auto&&... args)
+{
+    void* ptr = a.alloc(layout::of<T>());
+    return construct_at<T>(ptr, ASL_FWD(args)...);
+}
+
+template<typename T>
+void alloc_delete(allocator auto& a, T* ptr)
+{
+    destroy(ptr);
+    a.dealloc(ptr, layout::of<T>());
+}
+
+template<typename T>
+constexpr T* alloc_new_default(auto&&... args)
+{
+    return alloc_new<T>(DefaultAllocator{}, ASL_FWD(args)...);
+}
+
+template<typename T>
+void alloc_delete_default(T* ptr)
+{
+    alloc_delete(DefaultAllocator{}, ptr);
+}
+
 } // namespace asl
diff --git a/asl/integers.hpp b/asl/integers.hpp
index 65dadeb..5f6ad76 100644
--- a/asl/integers.hpp
+++ b/asl/integers.hpp
@@ -23,6 +23,8 @@ using uint32_t = unsigned int;
 using size_t  = uint64_t;
 using isize_t = int64_t;
 
+using uintptr_t = size_t;
+
 namespace asl
 {
     
diff --git a/asl/status.cpp b/asl/status.cpp
index e69de29..ac0b29e 100644
--- a/asl/status.cpp
+++ b/asl/status.cpp
@@ -0,0 +1,27 @@
+#include "asl/status.hpp"
+#include "asl/allocator.hpp"
+
+using Allocator = asl::DefaultAllocator;
+static Allocator g_allocator{};
+
+namespace
+{
+
+struct StatusInternal
+{
+    asl::string_view msg;
+    asl::status_code code;
+};
+
+} // anonymous namespace
+
+asl::status::status(status_code code, string_view msg)
+    : m_payload{alloc_new<StatusInternal>(g_allocator, msg, code)}
+{}
+
+asl::status_code asl::status::code_internal() const
+{
+    ASL_ASSERT(m_payload && (bit_cast<uintptr_t>(m_payload) & 1) == 0);
+    return reinterpret_cast<const StatusInternal*>(m_payload)->code;
+}
+
diff --git a/asl/status.hpp b/asl/status.hpp
index 2e4bae5..4638493 100644
--- a/asl/status.hpp
+++ b/asl/status.hpp
@@ -6,8 +6,77 @@
 namespace asl
 {
 
+enum class status_code : uint8_t
+{
+    ok               = 0,
+    unknown          = 1,
+    internal         = 2,
+    runtime          = 3,
+    invalid_argument = 4,
+};
+
 class status
 {
+    void* m_payload{};
+
+    static constexpr void* status_to_payload(status_code code)
+    {
+        return code == status_code::ok ? nullptr : bit_cast<void*>(((uintptr_t)code << 1) | 1);
+    }
+
+    static constexpr status_code payload_to_status(void* payload)
+    {
+        return (status_code)(bit_cast<uintptr_t>(payload) >> 1);
+    }
+
+    status_code code_internal() const;
+    
+public:
+    constexpr status() = default;
+    
+    explicit constexpr status(status_code code)
+        : m_payload{status_to_payload(code)}
+    {}
+
+    status(status_code code, string_view msg);
+
+    constexpr status(status&& other)
+        : m_payload{exchange(other.m_payload, nullptr)}
+    {}
+
+    constexpr status& operator=(status&& other)
+    {
+        if (&other != this)
+        {
+            swap(m_payload, other.m_payload);
+        }
+        return *this;
+    }
+
+    // @Todo Copy constructor & assignment
+
+    constexpr bool ok() const
+    {
+        return m_payload == nullptr || code() == status_code::ok;
+    }
+
+    // NOLINTNEXTLINE(*-explicit-conversions)
+    constexpr operator bool() const { return ok(); }
+
+    constexpr status_code code() const
+    {
+        if (m_payload == nullptr)
+        {
+            return status_code::ok;
+        }
+        
+        if ((bit_cast<uintptr_t>(m_payload) & 1) != 0)
+        {
+            return payload_to_status(m_payload);
+        }
+
+        return code_internal();
+    }
 };
 
 } // namespace asl
diff --git a/asl/tests/integers_tests.cpp b/asl/tests/integers_tests.cpp
index fdfa0fc..cfc1200 100644
--- a/asl/tests/integers_tests.cpp
+++ b/asl/tests/integers_tests.cpp
@@ -11,3 +11,5 @@ static_assert(sizeof(uint32_t) == 4);
 static_assert(sizeof(uint64_t) == 8);
 
 static_assert(sizeof(asl::byte) == 1);
+
+static_assert(sizeof(uintptr_t) == sizeof(void*));
diff --git a/asl/tests/status_tests.cpp b/asl/tests/status_tests.cpp
index e69de29..edfb65d 100644
--- a/asl/tests/status_tests.cpp
+++ b/asl/tests/status_tests.cpp
@@ -0,0 +1,27 @@
+#include "asl/status.hpp"
+#include "asl/testing/testing.hpp"
+
+ASL_TEST(simple_ok)
+{
+    asl::status s;
+    ASL_TEST_ASSERT(s);
+    ASL_TEST_ASSERT(s.ok());
+    ASL_TEST_ASSERT(s.code() == asl::status_code::ok);
+}
+
+ASL_TEST(simple_code)
+{
+    asl::status s{asl::status_code::runtime};
+    ASL_TEST_ASSERT(!s);
+    ASL_TEST_ASSERT(!s.ok());
+    ASL_TEST_ASSERT(s.code() == asl::status_code::runtime);
+}
+
+ASL_TEST(with_message)
+{
+    asl::status s{asl::status_code::internal, "We done goofed"};
+    ASL_TEST_ASSERT(!s);
+    ASL_TEST_ASSERT(!s.ok());
+    ASL_TEST_ASSERT(s.code() == asl::status_code::internal);
+    // @Todo test message
+}
diff --git a/asl/utility.hpp b/asl/utility.hpp
index 2877447..69838e5 100644
--- a/asl/utility.hpp
+++ b/asl/utility.hpp
@@ -11,6 +11,14 @@
 namespace asl
 {
 
+template<moveable T>
+constexpr void swap(T& a, T& b)
+{
+    T tmp{ASL_MOVE(a)};
+    a = ASL_MOVE(b);
+    b = ASL_MOVE(tmp);
+}
+
 template<typename T, typename U>
 T exchange(T& obj, U&& new_value)
 {
-- 
cgit