1 // -*- C++ -*- 2 //===----------------------------------------------------------------------===// 3 // 4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5 // See https://llvm.org/LICENSE.txt for license information. 6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef _LIBCPP___MEMORY_USES_ALLOCATOR_H 11 #define _LIBCPP___MEMORY_USES_ALLOCATOR_H 12 13 #include <__config> 14 #include <cstddef> 15 #include <type_traits> 16 17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 18 # pragma GCC system_header 19 #endif 20 21 _LIBCPP_BEGIN_NAMESPACE_STD 22 23 template <class _Tp> 24 struct __has_allocator_type 25 { 26 private: 27 template <class _Up> static false_type __test(...); 28 template <class _Up> static true_type __test(typename _Up::allocator_type* = 0); 29 public: 30 static const bool value = decltype(__test<_Tp>(0))::value; 31 }; 32 33 template <class _Tp, class _Alloc, bool = __has_allocator_type<_Tp>::value> 34 struct __uses_allocator 35 : public integral_constant<bool, 36 is_convertible<_Alloc, typename _Tp::allocator_type>::value> 37 { 38 }; 39 40 template <class _Tp, class _Alloc> 41 struct __uses_allocator<_Tp, _Alloc, false> 42 : public false_type 43 { 44 }; 45 46 template <class _Tp, class _Alloc> 47 struct _LIBCPP_TEMPLATE_VIS uses_allocator 48 : public __uses_allocator<_Tp, _Alloc> 49 { 50 }; 51 52 #if _LIBCPP_STD_VER > 14 53 template <class _Tp, class _Alloc> 54 inline constexpr size_t uses_allocator_v = uses_allocator<_Tp, _Alloc>::value; 55 #endif 56 57 _LIBCPP_END_NAMESPACE_STD 58 59 #endif // _LIBCPP___MEMORY_USES_ALLOCATOR_H 60