From f7a2699ac0cbb2824862439a72f23013436484de Mon Sep 17 00:00:00 2001
From: Steven Le Rouzic <steven.lerouzic@gmail.com>
Date: Wed, 14 May 2025 00:23:11 +0200
Subject: Add and use copy_const_t

---
 asl/base/meta.hpp                 |  2 ++
 asl/base/meta_tests.cpp           | 10 ++++++++++
 asl/containers/buffer.hpp         |  8 ++++----
 asl/containers/hash_map.hpp       |  2 +-
 asl/containers/intrusive_list.hpp |  4 ++--
 asl/types/array.hpp               |  6 +++---
 6 files changed, 22 insertions(+), 10 deletions(-)

diff --git a/asl/base/meta.hpp b/asl/base/meta.hpp
index 3675df3..e050e69 100644
--- a/asl/base/meta.hpp
+++ b/asl/base/meta.hpp
@@ -146,6 +146,8 @@ 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 {};
 
diff --git a/asl/base/meta_tests.cpp b/asl/base/meta_tests.cpp
index 7bae295..36b0429 100644
--- a/asl/base/meta_tests.cpp
+++ b/asl/base/meta_tests.cpp
@@ -274,6 +274,7 @@ 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>);
@@ -362,6 +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>);
diff --git a/asl/containers/buffer.hpp b/asl/containers/buffer.hpp
index d61abf9..0e30745 100644
--- a/asl/containers/buffer.hpp
+++ b/asl/containers/buffer.hpp
@@ -392,7 +392,7 @@ public:
 
     auto data(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>*;
         // NOLINTNEXTLINE(*-reinterpret-cast)
         auto&& buffer = reinterpret_cast<copy_cref_t<decltype(self), class buffer>>(self);
         if constexpr (kInlineCapacity == 0)
@@ -410,13 +410,13 @@ 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()};
     }
 
@@ -432,7 +432,7 @@ 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()};
     }
 
diff --git a/asl/containers/hash_map.hpp b/asl/containers/hash_map.hpp
index dc140eb..a6d72dd 100644
--- 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)
         {
diff --git a/asl/containers/intrusive_list.hpp b/asl/containers/intrusive_list.hpp
index 81816ec..5ce69aa 100644
--- 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 };
     }
 
diff --git a/asl/types/array.hpp b/asl/types/array.hpp
index 5fb300a..54c3fbe 100644
--- a/asl/types/array.hpp
+++ b/asl/types/array.hpp
@@ -19,12 +19,12 @@ struct array
     T m_data[kSize];
 
     [[nodiscard]] constexpr bool is_empty() const { return false; }
-    
+
     [[nodiscard]] constexpr int64_t size() const { return kSize; }
 
     constexpr auto data(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 static_cast<return_type>(self.m_data);
     }
 
@@ -54,7 +54,7 @@ struct array
 
     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, kSize>{self.data(), self.size()};
     }
 
-- 
cgit