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_CONSTRUCT_AT_H
11 #define _LIBCPP___MEMORY_CONSTRUCT_AT_H
12 
13 #include <__config>
14 #include <__debug>
15 #include <utility>
16 
17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
18 #pragma GCC system_header
19 #endif
20 
21 _LIBCPP_PUSH_MACROS
22 #include <__undef_macros>
23 
24 _LIBCPP_BEGIN_NAMESPACE_STD
25 
26 // construct_at
27 
28 #if _LIBCPP_STD_VER > 17
29 
30 template<class _Tp, class ..._Args, class = decltype(
31     ::new (declval<void*>()) _Tp(declval<_Args>()...)
32 )>
33 _LIBCPP_INLINE_VISIBILITY
construct_at(_Tp * __location,_Args &&...__args)34 constexpr _Tp* construct_at(_Tp* __location, _Args&& ...__args) {
35     _LIBCPP_ASSERT(__location, "null pointer given to construct_at");
36     return ::new ((void*)__location) _Tp(_VSTD::forward<_Args>(__args)...);
37 }
38 
39 #endif
40 
41 // destroy_at
42 
43 #if _LIBCPP_STD_VER > 14
44 
45 template <class _Tp>
46 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
destroy_at(_Tp * __loc)47 void destroy_at(_Tp* __loc) {
48     _LIBCPP_ASSERT(__loc, "null pointer given to destroy_at");
49     __loc->~_Tp();
50 }
51 
52 #endif
53 
54 _LIBCPP_END_NAMESPACE_STD
55 
56 _LIBCPP_POP_MACROS
57 
58 #endif // _LIBCPP___MEMORY_CONSTRUCT_AT_H
59