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/forward.h>
16 #include <utility>
17 
18 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
19 #pragma GCC system_header
20 #endif
21 
22 _LIBCPP_PUSH_MACROS
23 #include <__undef_macros>
24 
25 _LIBCPP_BEGIN_NAMESPACE_STD
26 
27 // construct_at
28 
29 #if _LIBCPP_STD_VER > 17
30 
31 template<class _Tp, class ..._Args, class = decltype(
32     ::new (declval<void*>()) _Tp(declval<_Args>()...)
33 )>
34 _LIBCPP_INLINE_VISIBILITY
construct_at(_Tp * __location,_Args &&...__args)35 constexpr _Tp* construct_at(_Tp* __location, _Args&& ...__args) {
36     _LIBCPP_ASSERT(__location, "null pointer given to construct_at");
37     return ::new ((void*)__location) _Tp(_VSTD::forward<_Args>(__args)...);
38 }
39 
40 #endif
41 
42 // destroy_at
43 
44 #if _LIBCPP_STD_VER > 14
45 
46 template <class _Tp>
47 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
destroy_at(_Tp * __loc)48 void destroy_at(_Tp* __loc) {
49     _LIBCPP_ASSERT(__loc, "null pointer given to destroy_at");
50     __loc->~_Tp();
51 }
52 
53 #endif
54 
55 _LIBCPP_END_NAMESPACE_STD
56 
57 _LIBCPP_POP_MACROS
58 
59 #endif // _LIBCPP___MEMORY_CONSTRUCT_AT_H
60