libcxx/include/__memory/allocate_at_least.h

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef _LIBCPP___MEMORY_ALLOCATE_AT_LEAST_H
  10 #define _LIBCPP___MEMORY_ALLOCATE_AT_LEAST_H
  11
  12 #include <__config>
  13 #include <__cstddef/size_t.h>
  14 #include <__memory/allocator_traits.h>
  15
  16 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  17 #  pragma GCC system_header
  18 #endif
  19
  20 _LIBCPP_BEGIN_NAMESPACE_STD
  21
  22 #if _LIBCPP_STD_VER >= 23
  23
  24 template <class _Alloc>
  25 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto __allocate_at_least(_Alloc& __alloc, size_t __n) {
  26   return std::allocator_traits<_Alloc>::allocate_at_least(__alloc, __n);
  27 }
  28
  29 #else
  30
  31 template <class _Pointer>
  32 struct __allocation_result {
  33   _Pointer ptr;
  34   size_t count;
  35 };
  36
  37 template <class _Alloc>
  38 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI
  39 _LIBCPP_CONSTEXPR __allocation_result<typename allocator_traits<_Alloc>::pointer>
  40 __allocate_at_least(_Alloc& __alloc, size_t __n) {
  41   return {__alloc.allocate(__n), __n};
  42 }
  43
  44 #endif // _LIBCPP_STD_VER >= 23
  45
  46 _LIBCPP_END_NAMESPACE_STD
  47
  48 #endif // _LIBCPP___MEMORY_ALLOCATE_AT_LEAST_H