llvm-project/libcxx/include/__memory/allocate_at_least.h

62 lines
1.7 KiB
C++

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___MEMORY_ALLOCATE_AT_LEAST_H
#define _LIBCPP___MEMORY_ALLOCATE_AT_LEAST_H
#include <__config>
#include <__memory/allocator_traits.h>
#include <cstddef>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
#if _LIBCPP_STD_VER > 20
template <class _Pointer>
struct allocation_result {
_Pointer ptr;
size_t count;
};
template <class _Alloc>
[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr
allocation_result<typename allocator_traits<_Alloc>::pointer> allocate_at_least(_Alloc& __alloc, size_t __n) {
if constexpr (requires { __alloc.allocate_at_least(__n); }) {
return __alloc.allocate_at_least(__n);
} else {
return {__alloc.allocate(__n), __n};
}
}
template <class _Alloc>
[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr
auto __allocate_at_least(_Alloc& __alloc, size_t __n) {
return std::allocate_at_least(__alloc, __n);
}
#else
template <class _Pointer>
struct __allocation_result {
_Pointer ptr;
size_t count;
};
template <class _Alloc>
_LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
__allocation_result<typename allocator_traits<_Alloc>::pointer> __allocate_at_least(_Alloc& __alloc, size_t __n) {
return {__alloc.allocate(__n), __n};
}
#endif // _LIBCPP_STD_VER > 20
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___MEMORY_ALLOCATE_AT_LEAST_H