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Howard Hinnantbc8d3f92010-05-11 19:42:16 +00001// -*- C++ -*-
2//===----------------------------- new ------------------------------------===//
3//
Howard Hinnantf5256e12010-05-11 21:36:01 +00004// The LLVM Compiler Infrastructure
Howard Hinnantbc8d3f92010-05-11 19:42:16 +00005//
Howard Hinnantb64f8b02010-11-16 22:09:02 +00006// This file is dual licensed under the MIT and the University of Illinois Open
7// Source Licenses. See LICENSE.TXT for details.
Howard Hinnantbc8d3f92010-05-11 19:42:16 +00008//
9//===----------------------------------------------------------------------===//
10
11#ifndef _LIBCPP_NEW
12#define _LIBCPP_NEW
13
14/*
15 new synopsis
16
17namespace std
18{
19
20class bad_alloc
21 : public exception
22{
23public:
Howard Hinnanted569212011-05-26 18:23:59 +000024 bad_alloc() noexcept;
25 bad_alloc(const bad_alloc&) noexcept;
26 bad_alloc& operator=(const bad_alloc&) noexcept;
27 virtual const char* what() const noexcept;
Howard Hinnantbc8d3f92010-05-11 19:42:16 +000028};
29
Eric Fiselier9acbffa2016-10-14 06:46:30 +000030class bad_array_length : public bad_alloc // FIXME: Not part of C++
Marshall Clow7f9f52e2013-09-11 01:38:42 +000031{
32public:
33 bad_array_length() noexcept;
34};
35
Eric Fiselier9acbffa2016-10-14 06:46:30 +000036class bad_array_new_length : public bad_alloc // C++14
Marshall Clow7f9f52e2013-09-11 01:38:42 +000037{
38public:
39 bad_array_new_length() noexcept;
40};
41
Eric Fiselier9acbffa2016-10-14 06:46:30 +000042enum class align_val_t : size_t {}; // C++17
Howard Hinnantbc8d3f92010-05-11 19:42:16 +000043struct nothrow_t {};
44extern const nothrow_t nothrow;
45typedef void (*new_handler)();
Howard Hinnanted569212011-05-26 18:23:59 +000046new_handler set_new_handler(new_handler new_p) noexcept;
47new_handler get_new_handler() noexcept;
Howard Hinnantbc8d3f92010-05-11 19:42:16 +000048
Marshall Clowaa0e2362017-11-22 19:49:03 +000049// 21.6.4, pointer optimization barrier
50template <class T> constexpr T* launder(T* p) noexcept; // C++17
Howard Hinnantbc8d3f92010-05-11 19:42:16 +000051} // std
52
Marshall Clow8f6293b2017-12-04 23:03:42 +000053void* operator new(std::size_t size); // replaceable, nodiscard in C++2a
54void* operator new(std::size_t size, std::align_val_t alignment); // replaceable, C++17, nodiscard in C++2a
55void* operator new(std::size_t size, const std::nothrow_t&) noexcept; // replaceable, nodiscard in C++2a
Eric Fiselier9acbffa2016-10-14 06:46:30 +000056void* operator new(std::size_t size, std::align_val_t alignment,
Marshall Clow8f6293b2017-12-04 23:03:42 +000057 const std::nothrow_t&) noexcept; // replaceable, C++17, nodiscard in C++2a
Howard Hinnanted569212011-05-26 18:23:59 +000058void operator delete(void* ptr) noexcept; // replaceable
Larisse Voufo19efe012015-02-15 05:18:55 +000059void operator delete(void* ptr, std::size_t size) noexcept; // replaceable, C++14
Eric Fiselier9acbffa2016-10-14 06:46:30 +000060void operator delete(void* ptr, std::align_val_t alignment) noexcept; // replaceable, C++17
61void operator delete(void* ptr, std::size_t size,
62 std::align_val_t alignment) noexcept; // replaceable, C++17
Howard Hinnanted569212011-05-26 18:23:59 +000063void operator delete(void* ptr, const std::nothrow_t&) noexcept; // replaceable
Eric Fiselier9acbffa2016-10-14 06:46:30 +000064void operator delete(void* ptr, std:align_val_t alignment,
65 const std::nothrow_t&) noexcept; // replaceable, C++17
Howard Hinnantbc8d3f92010-05-11 19:42:16 +000066
Marshall Clow8f6293b2017-12-04 23:03:42 +000067void* operator new[](std::size_t size); // replaceable, nodiscard in C++2a
Eric Fiselier9acbffa2016-10-14 06:46:30 +000068void* operator new[](std::size_t size,
Marshall Clow8f6293b2017-12-04 23:03:42 +000069 std::align_val_t alignment) noexcept; // replaceable, C++17, nodiscard in C++2a
70void* operator new[](std::size_t size, const std::nothrow_t&) noexcept; // replaceable, nodiscard in C++2a
Eric Fiselier9acbffa2016-10-14 06:46:30 +000071void* operator new[](std::size_t size, std::align_val_t alignment,
Marshall Clow8f6293b2017-12-04 23:03:42 +000072 const std::nothrow_t&) noexcept; // replaceable, C++17, nodiscard in C++2a
Howard Hinnanted569212011-05-26 18:23:59 +000073void operator delete[](void* ptr) noexcept; // replaceable
Larisse Voufo19efe012015-02-15 05:18:55 +000074void operator delete[](void* ptr, std::size_t size) noexcept; // replaceable, C++14
Eric Fiselier9acbffa2016-10-14 06:46:30 +000075void operator delete[](void* ptr,
76 std::align_val_t alignment) noexcept; // replaceable, C++17
77void operator delete[](void* ptr, std::size_t size,
78 std::align_val_t alignment) noexcept; // replaceable, C++17
Howard Hinnanted569212011-05-26 18:23:59 +000079void operator delete[](void* ptr, const std::nothrow_t&) noexcept; // replaceable
Eric Fiselier9acbffa2016-10-14 06:46:30 +000080void operator delete[](void* ptr, std::align_val_t alignment,
81 const std::nothrow_t&) noexcept; // replaceable, C++17
Howard Hinnantbc8d3f92010-05-11 19:42:16 +000082
Marshall Clow8f6293b2017-12-04 23:03:42 +000083void* operator new (std::size_t size, void* ptr) noexcept; // nodiscard in C++2a
84void* operator new[](std::size_t size, void* ptr) noexcept; // nodiscard in C++2a
Howard Hinnanted569212011-05-26 18:23:59 +000085void operator delete (void* ptr, void*) noexcept;
86void operator delete[](void* ptr, void*) noexcept;
Howard Hinnantbc8d3f92010-05-11 19:42:16 +000087
88*/
89
90#include <__config>
91#include <exception>
Eric Fiseliera8312872018-03-22 04:42:56 +000092#include <type_traits>
Howard Hinnantbc8d3f92010-05-11 19:42:16 +000093#include <cstddef>
Eric Fiselierdbf60fa2016-09-06 21:25:27 +000094#ifdef _LIBCPP_NO_EXCEPTIONS
95#include <cstdlib>
96#endif
Howard Hinnantbc8d3f92010-05-11 19:42:16 +000097
Shoaib Meenai18dba062017-10-09 19:25:17 +000098#if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
Eric Fiselier1edf3162017-02-10 08:57:35 +000099#include <new.h>
100#endif
101
Howard Hinnant08e17472011-10-17 20:05:10 +0000102#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
Howard Hinnantbc8d3f92010-05-11 19:42:16 +0000103#pragma GCC system_header
Howard Hinnant08e17472011-10-17 20:05:10 +0000104#endif
Howard Hinnantbc8d3f92010-05-11 19:42:16 +0000105
Eric Fiselier9acbffa2016-10-14 06:46:30 +0000106#if !(defined(_LIBCPP_BUILDING_NEW) || _LIBCPP_STD_VER >= 14 || \
107 (defined(__cpp_sized_deallocation) && __cpp_sized_deallocation >= 201309))
108# define _LIBCPP_HAS_NO_SIZED_DEALLOCATION
109#endif
110
Eric Fiselierd54d9742017-01-20 01:47:26 +0000111#if !defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION) && \
112 (!(defined(_LIBCPP_BUILDING_NEW) || _LIBCPP_STD_VER > 14 || \
113 (defined(__cpp_aligned_new) && __cpp_aligned_new >= 201606)))
Eric Fiselier9acbffa2016-10-14 06:46:30 +0000114# define _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
115#endif
116
Eric Fiseliera8312872018-03-22 04:42:56 +0000117
118#if !__has_builtin(__builtin_operator_new) || \
119 __has_builtin(__builtin_operator_new) < 201802L || \
120 defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION) || \
121 !defined(__cpp_aligned_new) || __cpp_aligned_new < 201606
122#define _LIBCPP_HAS_NO_BUILTIN_ALIGNED_OPERATOR_NEW_DELETE
123#endif
124
Howard Hinnantbc8d3f92010-05-11 19:42:16 +0000125namespace std // purposefully not using versioning namespace
126{
127
Shoaib Meenai18dba062017-10-09 19:25:17 +0000128#if !defined(_LIBCPP_ABI_MICROSOFT) || defined(_LIBCPP_NO_VCRUNTIME)
Eric Fiselier1edf3162017-02-10 08:57:35 +0000129struct _LIBCPP_TYPE_VIS nothrow_t {};
130extern _LIBCPP_FUNC_VIS const nothrow_t nothrow;
131
Howard Hinnantbc8d3f92010-05-11 19:42:16 +0000132class _LIBCPP_EXCEPTION_ABI bad_alloc
133 : public exception
134{
135public:
Howard Hinnanted569212011-05-26 18:23:59 +0000136 bad_alloc() _NOEXCEPT;
137 virtual ~bad_alloc() _NOEXCEPT;
138 virtual const char* what() const _NOEXCEPT;
Howard Hinnantbc8d3f92010-05-11 19:42:16 +0000139};
140
141class _LIBCPP_EXCEPTION_ABI bad_array_new_length
142 : public bad_alloc
143{
144public:
Howard Hinnanted569212011-05-26 18:23:59 +0000145 bad_array_new_length() _NOEXCEPT;
146 virtual ~bad_array_new_length() _NOEXCEPT;
147 virtual const char* what() const _NOEXCEPT;
Howard Hinnantbc8d3f92010-05-11 19:42:16 +0000148};
149
Eric Fiselier1edf3162017-02-10 08:57:35 +0000150typedef void (*new_handler)();
151_LIBCPP_FUNC_VIS new_handler set_new_handler(new_handler) _NOEXCEPT;
152_LIBCPP_FUNC_VIS new_handler get_new_handler() _NOEXCEPT;
153
Shoaib Meenai18dba062017-10-09 19:25:17 +0000154#endif // !_LIBCPP_ABI_MICROSOFT || _LIBCPP_NO_VCRUNTIME
Eric Fiselier1edf3162017-02-10 08:57:35 +0000155
Marshall Clow14c09a22016-08-25 15:09:01 +0000156_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void __throw_bad_alloc(); // not in C++ spec
157
Eric Fiselier1edf3162017-02-10 08:57:35 +0000158#if defined(_LIBCPP_BUILDING_LIBRARY) || (_LIBCPP_STD_VER > 11)
Howard Hinnant29250b72013-11-07 17:15:51 +0000159
Mehdi Amini907c1192017-05-04 17:08:54 +0000160class _LIBCPP_EXCEPTION_ABI _LIBCPP_AVAILABILITY_BAD_ARRAY_LENGTH
161 bad_array_length : public bad_alloc {
Marshall Clow7f9f52e2013-09-11 01:38:42 +0000162public:
163 bad_array_length() _NOEXCEPT;
164 virtual ~bad_array_length() _NOEXCEPT;
165 virtual const char* what() const _NOEXCEPT;
166};
Howard Hinnant29250b72013-11-07 17:15:51 +0000167
168#define _LIBCPP_BAD_ARRAY_LENGTH_DEFINED
169
170#endif // defined(_LIBCPP_BUILDING_NEW) || (_LIBCPP_STD_VER > 11)
Marshall Clow7f9f52e2013-09-11 01:38:42 +0000171
Eric Fiselier22a291c2018-02-11 22:00:19 +0000172#if !defined(_LIBCPP_ABI_MICROSOFT) || defined(_LIBCPP_NO_VCRUNTIME)
Eric Fiselier85e34e42017-01-21 14:42:44 +0000173#if !defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION) || _LIBCPP_STD_VER > 14
Eric Fiselier9acbffa2016-10-14 06:46:30 +0000174#ifndef _LIBCPP_CXX03_LANG
175enum class _LIBCPP_ENUM_VIS align_val_t : size_t { };
176#else
177enum align_val_t { __zero = 0, __max = (size_t)-1 };
178#endif
179#endif
Eric Fiselier22a291c2018-02-11 22:00:19 +0000180#endif
Eric Fiselier9acbffa2016-10-14 06:46:30 +0000181
Howard Hinnantbc8d3f92010-05-11 19:42:16 +0000182} // std
183
Eric Fiselierb45121d2017-01-02 23:27:42 +0000184#if defined(_LIBCPP_CXX03_LANG)
Eric Fiselier9acbffa2016-10-14 06:46:30 +0000185#define _THROW_BAD_ALLOC throw(std::bad_alloc)
186#else
187#define _THROW_BAD_ALLOC
Howard Hinnanted569212011-05-26 18:23:59 +0000188#endif
Eric Fiselier9acbffa2016-10-14 06:46:30 +0000189
Shoaib Meenai18dba062017-10-09 19:25:17 +0000190#if !defined(_LIBCPP_ABI_MICROSOFT) || defined(_LIBCPP_NO_VCRUNTIME)
Eric Fiselier1edf3162017-02-10 08:57:35 +0000191
Marshall Clow8f6293b2017-12-04 23:03:42 +0000192_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz) _THROW_BAD_ALLOC;
193_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz, const std::nothrow_t&) _NOEXCEPT _NOALIAS;
Shoaib Meenaie6479bc2016-11-16 22:18:10 +0000194_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p) _NOEXCEPT;
195_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p, const std::nothrow_t&) _NOEXCEPT;
Eric Fiselier9acbffa2016-10-14 06:46:30 +0000196#ifndef _LIBCPP_HAS_NO_SIZED_DEALLOCATION
Mehdi Amini907c1192017-05-04 17:08:54 +0000197_LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_AVAILABILITY_SIZED_NEW_DELETE void operator delete(void* __p, std::size_t __sz) _NOEXCEPT;
Larisse Voufo74f95a02015-02-20 06:13:05 +0000198#endif
Howard Hinnant0f678bd2013-08-12 18:38:34 +0000199
Marshall Clow8f6293b2017-12-04 23:03:42 +0000200_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz) _THROW_BAD_ALLOC;
201_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz, const std::nothrow_t&) _NOEXCEPT _NOALIAS;
Shoaib Meenaie6479bc2016-11-16 22:18:10 +0000202_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p) _NOEXCEPT;
203_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p, const std::nothrow_t&) _NOEXCEPT;
Shoaib Meenaif66194b2016-11-18 04:31:09 +0000204#ifndef _LIBCPP_HAS_NO_SIZED_DEALLOCATION
Mehdi Amini907c1192017-05-04 17:08:54 +0000205_LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_AVAILABILITY_SIZED_NEW_DELETE void operator delete[](void* __p, std::size_t __sz) _NOEXCEPT;
Larisse Voufo74f95a02015-02-20 06:13:05 +0000206#endif
Howard Hinnant0f678bd2013-08-12 18:38:34 +0000207
Eric Fiselier9acbffa2016-10-14 06:46:30 +0000208#ifndef _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
Marshall Clow8f6293b2017-12-04 23:03:42 +0000209_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz, std::align_val_t) _THROW_BAD_ALLOC;
210_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz, std::align_val_t, const std::nothrow_t&) _NOEXCEPT _NOALIAS;
Akira Hatanakac5247b42017-06-30 18:50:23 +0000211_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p, std::align_val_t) _NOEXCEPT;
212_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p, std::align_val_t, const std::nothrow_t&) _NOEXCEPT;
Eric Fiselier9acbffa2016-10-14 06:46:30 +0000213#ifndef _LIBCPP_HAS_NO_SIZED_DEALLOCATION
Akira Hatanakac5247b42017-06-30 18:50:23 +0000214_LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_AVAILABILITY_SIZED_NEW_DELETE void operator delete(void* __p, std::size_t __sz, std::align_val_t) _NOEXCEPT;
Eric Fiselier9acbffa2016-10-14 06:46:30 +0000215#endif
216
Marshall Clow8f6293b2017-12-04 23:03:42 +0000217_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz, std::align_val_t) _THROW_BAD_ALLOC;
218_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz, std::align_val_t, const std::nothrow_t&) _NOEXCEPT _NOALIAS;
Akira Hatanakac5247b42017-06-30 18:50:23 +0000219_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p, std::align_val_t) _NOEXCEPT;
220_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p, std::align_val_t, const std::nothrow_t&) _NOEXCEPT;
Eric Fiselier9acbffa2016-10-14 06:46:30 +0000221#ifndef _LIBCPP_HAS_NO_SIZED_DEALLOCATION
Akira Hatanakac5247b42017-06-30 18:50:23 +0000222_LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_AVAILABILITY_SIZED_NEW_DELETE void operator delete[](void* __p, std::size_t __sz, std::align_val_t) _NOEXCEPT;
Eric Fiselier9acbffa2016-10-14 06:46:30 +0000223#endif
224#endif
225
Marshall Clow8f6293b2017-12-04 23:03:42 +0000226_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY void* operator new (std::size_t, void* __p) _NOEXCEPT {return __p;}
227_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY void* operator new[](std::size_t, void* __p) _NOEXCEPT {return __p;}
Howard Hinnant1e564242013-10-04 22:09:00 +0000228inline _LIBCPP_INLINE_VISIBILITY void operator delete (void*, void*) _NOEXCEPT {}
229inline _LIBCPP_INLINE_VISIBILITY void operator delete[](void*, void*) _NOEXCEPT {}
Howard Hinnantbc8d3f92010-05-11 19:42:16 +0000230
Shoaib Meenai18dba062017-10-09 19:25:17 +0000231#endif // !_LIBCPP_ABI_MICROSOFT || _LIBCPP_NO_VCRUNTIME
Eric Fiselier1edf3162017-02-10 08:57:35 +0000232
Richard Smith73c1fce2014-06-04 19:54:15 +0000233_LIBCPP_BEGIN_NAMESPACE_STD
234
Eric Fiseliera8312872018-03-22 04:42:56 +0000235_LIBCPP_CONSTEXPR inline _LIBCPP_INLINE_VISIBILITY bool __is_overaligned_for_new(size_t __align) _NOEXCEPT {
236#ifdef __STDCPP_DEFAULT_NEW_ALIGNMENT__
237 return __align > __STDCPP_DEFAULT_NEW_ALIGNMENT__;
238#else
239 return __align > alignment_of<max_align_t>::value;
240#endif
241}
242
243inline _LIBCPP_INLINE_VISIBILITY void *__libcpp_allocate(size_t __size, size_t __align) {
244#ifndef _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
245 if (__is_overaligned_for_new(__align)) {
246 const align_val_t __align_val = static_cast<align_val_t>(__align);
247# ifdef _LIBCPP_HAS_NO_BUILTIN_ALIGNED_OPERATOR_NEW_DELETE
248 return ::operator new(__size, __align_val);
249# else
250 return __builtin_operator_new(__size, __align_val);
251# endif
252 }
253#else
254 ((void)__align);
255#endif
Richard Smith73c1fce2014-06-04 19:54:15 +0000256#ifdef _LIBCPP_HAS_NO_BUILTIN_OPERATOR_NEW_DELETE
257 return ::operator new(__size);
258#else
259 return __builtin_operator_new(__size);
260#endif
261}
262
Eric Fiseliera8312872018-03-22 04:42:56 +0000263inline _LIBCPP_INLINE_VISIBILITY void __libcpp_deallocate(void* __ptr, size_t __align) {
264#ifndef _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
265 if (__is_overaligned_for_new(__align)) {
266 const align_val_t __align_val = static_cast<align_val_t>(__align);
267# ifdef _LIBCPP_HAS_NO_BUILTIN_ALIGNED_OPERATOR_NEW_DELETE
268 return ::operator delete(__ptr, __align_val);
269# else
270 return __builtin_operator_delete(__ptr, __align_val);
271# endif
272 }
Richard Smith73c1fce2014-06-04 19:54:15 +0000273#else
Eric Fiseliera8312872018-03-22 04:42:56 +0000274 ((void)__align);
275#endif
276#ifdef _LIBCPP_HAS_NO_BUILTIN_OPERATOR_NEW_DELETE
277 return ::operator delete(__ptr);
278#else
279 return __builtin_operator_delete(__ptr);
Richard Smith73c1fce2014-06-04 19:54:15 +0000280#endif
281}
282
Marshall Clow14c09a22016-08-25 15:09:01 +0000283#ifdef _LIBCPP_BAD_ARRAY_LENGTH_DEFINED
284_LIBCPP_NORETURN inline _LIBCPP_ALWAYS_INLINE
Mehdi Amini907c1192017-05-04 17:08:54 +0000285#ifndef _LIBCPP_NO_EXCEPTIONS
286_LIBCPP_AVAILABILITY_BAD_ARRAY_LENGTH
287#endif
Marshall Clow14c09a22016-08-25 15:09:01 +0000288void __throw_bad_array_length()
289{
290#ifndef _LIBCPP_NO_EXCEPTIONS
291 throw bad_array_length();
292#else
293 _VSTD::abort();
294#endif
295}
296#endif
297
Marshall Clowaa0e2362017-11-22 19:49:03 +0000298template <class _Tp>
299_LIBCPP_NODISCARD_AFTER_CXX17 inline
300_LIBCPP_CONSTEXPR _Tp* __launder(_Tp* __p) _NOEXCEPT
301{
302 static_assert (!(is_function<_Tp>::value), "can't launder functions" );
303 static_assert (!(is_same<void, typename remove_cv<_Tp>::type>::value), "can't launder cv-void" );
304#ifdef _LIBCPP_COMPILER_HAS_BUILTIN_LAUNDER
305 return __builtin_launder(__p);
306#else
307 return __p;
308#endif
309}
310
311
312#if _LIBCPP_STD_VER > 14
313template <class _Tp>
314_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY
315constexpr _Tp* launder(_Tp* __p) noexcept
316{
Marshall Clow70c7bbd2017-11-23 01:25:03 +0000317 return _VSTD::__launder(__p);
Marshall Clowaa0e2362017-11-22 19:49:03 +0000318}
319#endif
320
Richard Smith73c1fce2014-06-04 19:54:15 +0000321_LIBCPP_END_NAMESPACE_STD
322
Howard Hinnantbc8d3f92010-05-11 19:42:16 +0000323#endif // _LIBCPP_NEW