[libcxx-commits] [libcxx] [libc++] Use __alloc_traits whenever it is available for consistency (PR #126595)

[via libcxx-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-libcxx

Author: Peng Liu (winner245)

<details>
<summary>Changes</summary>

When an allocator-aware container already defines a member type alias `__alloc_traits` for `std::allocator_traits<allocator_type>`, we should consistently use `__alloc_traits`. Mixing the usage of both `__alloc_traits` and `std::allocator_traits` can lead to inconsistencies and confusion.

---
Full diff: https://github.com/llvm/llvm-project/pull/126595.diff


3 Files Affected:

- (modified) libcxx/include/deque (+4-4) 
- (modified) libcxx/include/forward_list (+2-2) 
- (modified) libcxx/include/list (+2-2) 


``````````diff
diff --git a/libcxx/include/deque b/libcxx/include/deque
index 95200b4801d7ff3..ce29286445d4c45 100644
--- a/libcxx/include/deque
+++ b/libcxx/include/deque
@@ -61,7 +61,7 @@ public:
     deque& operator=(deque&& c)
         noexcept((__alloc_traits::propagate_on_container_move_assignment::value &&
                   is_nothrow_move_assignable<allocator_type>::value) ||
-                 allocator_traits<allocator_type>::is_always_equal::value);
+                 __alloc_traits::is_always_equal::value);
     deque& operator=(initializer_list<value_type> il);
 
     template <class InputIterator>
@@ -133,7 +133,7 @@ public:
     iterator erase(const_iterator p);
     iterator erase(const_iterator f, const_iterator l);
     void swap(deque& c)
-        noexcept(allocator_traits<allocator_type>::is_always_equal::value);  // C++17
+        noexcept(__alloc_traits::is_always_equal::value);  // C++17
     void clear() noexcept;
 };
 
@@ -677,7 +677,7 @@ public:
   _LIBCPP_HIDE_FROM_ABI deque& operator=(deque&& __c) noexcept(
       (__alloc_traits::propagate_on_container_move_assignment::value &&
        is_nothrow_move_assignable<allocator_type>::value) ||
-      allocator_traits<allocator_type>::is_always_equal::value);
+      __alloc_traits::is_always_equal::value);
 
   _LIBCPP_HIDE_FROM_ABI void assign(initializer_list<value_type> __il) { assign(__il.begin(), __il.end()); }
 #  endif // _LIBCPP_CXX03_LANG
@@ -1382,7 +1382,7 @@ template <class _Tp, class _Allocator>
 inline deque<_Tp, _Allocator>& deque<_Tp, _Allocator>::operator=(deque&& __c) noexcept(
     (__alloc_traits::propagate_on_container_move_assignment::value &&
      is_nothrow_move_assignable<allocator_type>::value) ||
-    allocator_traits<allocator_type>::is_always_equal::value) {
+    __alloc_traits::is_always_equal::value) {
   __move_assign(__c, integral_constant<bool, __alloc_traits::propagate_on_container_move_assignment::value>());
   return *this;
 }
diff --git a/libcxx/include/forward_list b/libcxx/include/forward_list
index 4b6ca8ea8587c08..79d144e6421064d 100644
--- a/libcxx/include/forward_list
+++ b/libcxx/include/forward_list
@@ -719,7 +719,7 @@ public:
   _LIBCPP_HIDE_FROM_ABI forward_list& operator=(forward_list&& __x) noexcept(
       (__node_traits::propagate_on_container_move_assignment::value &&
        is_nothrow_move_assignable<allocator_type>::value) ||
-      allocator_traits<allocator_type>::is_always_equal::value);
+      __node_traits::is_always_equal::value);
 
   _LIBCPP_HIDE_FROM_ABI forward_list& operator=(initializer_list<value_type> __il);
 
@@ -1013,7 +1013,7 @@ template <class _Tp, class _Alloc>
 inline forward_list<_Tp, _Alloc>& forward_list<_Tp, _Alloc>::operator=(forward_list&& __x) noexcept(
     (__node_traits::propagate_on_container_move_assignment::value &&
      is_nothrow_move_assignable<allocator_type>::value) ||
-    allocator_traits<allocator_type>::is_always_equal::value) {
+    __node_traits::is_always_equal::value) {
   __move_assign(__x, integral_constant<bool, __node_traits::propagate_on_container_move_assignment::value>());
   return *this;
 }
diff --git a/libcxx/include/list b/libcxx/include/list
index 3fcf796ebc03d04..9cdb7ffd78af02b 100644
--- a/libcxx/include/list
+++ b/libcxx/include/list
@@ -731,7 +731,7 @@ public:
   _LIBCPP_HIDE_FROM_ABI list& operator=(list&& __c) noexcept(
       (__node_alloc_traits::propagate_on_container_move_assignment::value &&
        is_nothrow_move_assignable<__node_allocator>::value) ||
-      allocator_traits<allocator_type>::is_always_equal::value);
+      __node_alloc_traits::is_always_equal::value);
 
   _LIBCPP_HIDE_FROM_ABI list& operator=(initializer_list<value_type> __il) {
     assign(__il.begin(), __il.end());
@@ -1070,7 +1070,7 @@ template <class _Tp, class _Alloc>
 inline list<_Tp, _Alloc>& list<_Tp, _Alloc>::operator=(list&& __c) noexcept(
     (__node_alloc_traits::propagate_on_container_move_assignment::value &&
      is_nothrow_move_assignable<__node_allocator>::value) ||
-    allocator_traits<allocator_type>::is_always_equal::value) {
+    __node_alloc_traits::is_always_equal::value) {
   __move_assign(__c, integral_constant<bool, __node_alloc_traits::propagate_on_container_move_assignment::value>());
   return *this;
 }

``````````

</details>


https://github.com/llvm/llvm-project/pull/126595