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___TYPE_IS_ALLOCATOR_H
10#define _LIBCPP___TYPE_IS_ALLOCATOR_H
11
12#include <__config>
13#include <__type_traits/integral_constant.h>
14#include <__type_traits/void_t.h>
15#include <__utility/declval.h>
16#include <cstddef>
17
18#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
19#  pragma GCC system_header
20#endif
21
22_LIBCPP_BEGIN_NAMESPACE_STD
23
24template<typename _Alloc, typename = void, typename = void>
25struct __is_allocator : false_type {};
26
27template<typename _Alloc>
28struct __is_allocator<_Alloc,
29       __void_t<typename _Alloc::value_type>,
30       __void_t<decltype(std::declval<_Alloc&>().allocate(size_t(0)))>
31     >
32   : true_type {};
33
34_LIBCPP_END_NAMESPACE_STD
35
36#endif // _LIBCPP___TYPE_IS_ALLOCATOR_H
37