__cxx03/__memory/allocate_at_least.h

0001 //===----------------------------------------------------------------------===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===----------------------------------------------------------------------===//
0008
0009 #ifndef _LIBCPP___CXX03___MEMORY_ALLOCATE_AT_LEAST_H
0010 #define _LIBCPP___CXX03___MEMORY_ALLOCATE_AT_LEAST_H
0011
0012 #include <__cxx03/__config>
0013 #include <__cxx03/__memory/allocator_traits.h>
0014 #include <__cxx03/cstddef>
0015
0016 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
0017 #  pragma GCC system_header
0018 #endif
0019
0020 _LIBCPP_BEGIN_NAMESPACE_STD
0021
0022 #if _LIBCPP_STD_VER >= 23
0023
0024 template <class _Alloc>
0025 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto __allocate_at_least(_Alloc& __alloc, size_t __n) {
0026   return std::allocator_traits<_Alloc>::allocate_at_least(__alloc, __n);
0027 }
0028
0029 #else
0030
0031 template <class _Pointer>
0032 struct __allocation_result {
0033   _Pointer ptr;
0034   size_t count;
0035 };
0036
0037 template <class _Alloc>
0038 _LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI
0039 _LIBCPP_CONSTEXPR __allocation_result<typename allocator_traits<_Alloc>::pointer>
0040 __allocate_at_least(_Alloc& __alloc, size_t __n) {
0041   return {__alloc.allocate(__n), __n};
0042 }
0043
0044 #endif // _LIBCPP_STD_VER >= 23
0045
0046 _LIBCPP_END_NAMESPACE_STD
0047
0048 #endif // _LIBCPP___CXX03___MEMORY_ALLOCATE_AT_LEAST_H