master
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___FUNCTIONAL_FUNCTION_H
11#define _LIBCPP___FUNCTIONAL_FUNCTION_H
12
13#include <__assert>
14#include <__config>
15#include <__cstddef/nullptr_t.h>
16#include <__exception/exception.h>
17#include <__functional/binary_function.h>
18#include <__functional/invoke.h>
19#include <__functional/unary_function.h>
20#include <__memory/addressof.h>
21#include <__type_traits/aligned_storage.h>
22#include <__type_traits/decay.h>
23#include <__type_traits/is_core_convertible.h>
24#include <__type_traits/is_scalar.h>
25#include <__type_traits/is_trivially_constructible.h>
26#include <__type_traits/is_trivially_destructible.h>
27#include <__type_traits/is_void.h>
28#include <__type_traits/strip_signature.h>
29#include <__utility/forward.h>
30#include <__utility/move.h>
31#include <__utility/swap.h>
32#include <tuple>
33#include <typeinfo>
34
35#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
36# pragma GCC system_header
37#endif
38
39_LIBCPP_PUSH_MACROS
40#include <__undef_macros>
41
42#ifndef _LIBCPP_CXX03_LANG
43
44_LIBCPP_BEGIN_NAMESPACE_STD
45
46// bad_function_call
47
48_LIBCPP_DIAGNOSTIC_PUSH
49# if !_LIBCPP_AVAILABILITY_HAS_BAD_FUNCTION_CALL_KEY_FUNCTION
50_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wweak-vtables")
51# endif
52class _LIBCPP_EXPORTED_FROM_ABI bad_function_call : public exception {
53public:
54 _LIBCPP_HIDE_FROM_ABI bad_function_call() _NOEXCEPT = default;
55 _LIBCPP_HIDE_FROM_ABI bad_function_call(const bad_function_call&) _NOEXCEPT = default;
56 _LIBCPP_HIDE_FROM_ABI bad_function_call& operator=(const bad_function_call&) _NOEXCEPT = default;
57// Note that when a key function is not used, every translation unit that uses
58// bad_function_call will end up containing a weak definition of the vtable and
59// typeinfo.
60# if _LIBCPP_AVAILABILITY_HAS_BAD_FUNCTION_CALL_KEY_FUNCTION
61 ~bad_function_call() _NOEXCEPT override;
62# else
63 _LIBCPP_HIDE_FROM_ABI_VIRTUAL ~bad_function_call() _NOEXCEPT override {}
64# endif
65
66# if _LIBCPP_AVAILABILITY_HAS_BAD_FUNCTION_CALL_GOOD_WHAT_MESSAGE
67 const char* what() const _NOEXCEPT override;
68# endif
69};
70_LIBCPP_DIAGNOSTIC_POP
71
72[[__noreturn__]] inline _LIBCPP_HIDE_FROM_ABI void __throw_bad_function_call() {
73# if _LIBCPP_HAS_EXCEPTIONS
74 throw bad_function_call();
75# else
76 _LIBCPP_VERBOSE_ABORT("bad_function_call was thrown in -fno-exceptions mode");
77# endif
78}
79
80template <class _Fp>
81class function; // undefined
82
83namespace __function {
84
85template <class _Rp>
86struct __maybe_derive_from_unary_function {};
87
88template <class _Rp, class _A1>
89struct __maybe_derive_from_unary_function<_Rp(_A1)> : public __unary_function<_A1, _Rp> {};
90
91template <class _Rp>
92struct __maybe_derive_from_binary_function {};
93
94template <class _Rp, class _A1, class _A2>
95struct __maybe_derive_from_binary_function<_Rp(_A1, _A2)> : public __binary_function<_A1, _A2, _Rp> {};
96
97template <class _Fp>
98_LIBCPP_HIDE_FROM_ABI bool __not_null(_Fp const&) {
99 return true;
100}
101
102template <class _Fp>
103_LIBCPP_HIDE_FROM_ABI bool __not_null(_Fp* __ptr) {
104 return __ptr;
105}
106
107template <class _Ret, class _Class>
108_LIBCPP_HIDE_FROM_ABI bool __not_null(_Ret _Class::*__ptr) {
109 return __ptr;
110}
111
112template <class _Fp>
113_LIBCPP_HIDE_FROM_ABI bool __not_null(function<_Fp> const& __f) {
114 return !!__f;
115}
116
117# if __has_extension(blocks)
118template <class _Rp, class... _Args>
119_LIBCPP_HIDE_FROM_ABI bool __not_null(_Rp (^__p)(_Args...)) {
120 return __p;
121}
122# endif
123
124} // namespace __function
125
126namespace __function {
127
128// __base provides an abstract interface for copyable functors.
129
130template <class _Fp>
131class __base;
132
133template <class _Rp, class... _ArgTypes>
134class __base<_Rp(_ArgTypes...)> {
135public:
136 __base(const __base&) = delete;
137 __base& operator=(const __base&) = delete;
138
139 _LIBCPP_HIDE_FROM_ABI __base() {}
140 _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual ~__base() {}
141 virtual __base* __clone() const = 0;
142 virtual void __clone(__base*) const = 0;
143 virtual void destroy() _NOEXCEPT = 0;
144 virtual void destroy_deallocate() _NOEXCEPT = 0;
145 virtual _Rp operator()(_ArgTypes&&...) = 0;
146# if _LIBCPP_HAS_RTTI
147 virtual const void* target(const type_info&) const _NOEXCEPT = 0;
148 virtual const std::type_info& target_type() const _NOEXCEPT = 0;
149# endif // _LIBCPP_HAS_RTTI
150};
151
152// __func implements __base for a given functor type.
153
154template <class _FD, class _FB>
155class __func;
156
157template <class _Fp, class _Rp, class... _ArgTypes>
158class __func<_Fp, _Rp(_ArgTypes...)> : public __base<_Rp(_ArgTypes...)> {
159 _Fp __func_;
160
161public:
162 _LIBCPP_HIDE_FROM_ABI explicit __func(_Fp&& __f) : __func_(std::move(__f)) {}
163 _LIBCPP_HIDE_FROM_ABI explicit __func(const _Fp& __f) : __func_(__f) {}
164
165 _LIBCPP_HIDE_FROM_ABI_VIRTUAL __base<_Rp(_ArgTypes...)>* __clone() const override { return new __func(__func_); }
166
167 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __clone(__base<_Rp(_ArgTypes...)>* __p) const override {
168 ::new ((void*)__p) __func(__func_);
169 }
170
171 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void destroy() _NOEXCEPT override { __func_.~_Fp(); }
172 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void destroy_deallocate() _NOEXCEPT override { delete this; }
173 _LIBCPP_HIDE_FROM_ABI_VIRTUAL _Rp operator()(_ArgTypes&&... __arg) override {
174 return std::__invoke_r<_Rp>(__func_, std::forward<_ArgTypes>(__arg)...);
175 }
176# if _LIBCPP_HAS_RTTI
177 _LIBCPP_HIDE_FROM_ABI_VIRTUAL const void* target(const type_info& __ti) const _NOEXCEPT override {
178 if (__ti == typeid(_Fp))
179 return std::addressof(__func_);
180 return nullptr;
181 }
182 _LIBCPP_HIDE_FROM_ABI_VIRTUAL const std::type_info& target_type() const _NOEXCEPT override { return typeid(_Fp); }
183# endif // _LIBCPP_HAS_RTTI
184};
185
186// __value_func creates a value-type from a __func.
187
188template <class _Fp>
189class __value_func;
190
191template <class _Rp, class... _ArgTypes>
192class __value_func<_Rp(_ArgTypes...)> {
193 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
194 typename aligned_storage<3 * sizeof(void*)>::type __buf_;
195 _LIBCPP_SUPPRESS_DEPRECATED_POP
196
197 typedef __base<_Rp(_ArgTypes...)> __func;
198 __func* __f_;
199
200 _LIBCPP_HIDE_FROM_ABI _LIBCPP_NO_CFI static __func* __as_base(void* __p) { return reinterpret_cast<__func*>(__p); }
201
202public:
203 _LIBCPP_HIDE_FROM_ABI __value_func() _NOEXCEPT : __f_(nullptr) {}
204
205 template <class _Fp, __enable_if_t<!is_same<__decay_t<_Fp>, __value_func>::value, int> = 0>
206 _LIBCPP_HIDE_FROM_ABI explicit __value_func(_Fp&& __f) : __f_(nullptr) {
207 typedef __function::__func<_Fp, _Rp(_ArgTypes...)> _Fun;
208
209 if (__function::__not_null(__f)) {
210 if (sizeof(_Fun) <= sizeof(__buf_) && is_nothrow_copy_constructible<_Fp>::value) {
211 __f_ = ::new (std::addressof(__buf_)) _Fun(std::move(__f));
212 } else {
213 __f_ = new _Fun(std::move(__f));
214 }
215 }
216 }
217
218 _LIBCPP_HIDE_FROM_ABI __value_func(const __value_func& __f) {
219 if (__f.__f_ == nullptr)
220 __f_ = nullptr;
221 else if ((void*)__f.__f_ == &__f.__buf_) {
222 __f_ = __as_base(&__buf_);
223 __f.__f_->__clone(__f_);
224 } else
225 __f_ = __f.__f_->__clone();
226 }
227
228 _LIBCPP_HIDE_FROM_ABI __value_func(__value_func&& __f) _NOEXCEPT {
229 if (__f.__f_ == nullptr)
230 __f_ = nullptr;
231 else if ((void*)__f.__f_ == &__f.__buf_) {
232 __f_ = __as_base(&__buf_);
233 __f.__f_->__clone(__f_);
234 } else {
235 __f_ = __f.__f_;
236 __f.__f_ = nullptr;
237 }
238 }
239
240 _LIBCPP_HIDE_FROM_ABI ~__value_func() {
241 if ((void*)__f_ == &__buf_)
242 __f_->destroy();
243 else if (__f_)
244 __f_->destroy_deallocate();
245 }
246
247 _LIBCPP_HIDE_FROM_ABI __value_func& operator=(__value_func&& __f) {
248 *this = nullptr;
249 if (__f.__f_ == nullptr)
250 __f_ = nullptr;
251 else if ((void*)__f.__f_ == &__f.__buf_) {
252 __f_ = __as_base(&__buf_);
253 __f.__f_->__clone(__f_);
254 } else {
255 __f_ = __f.__f_;
256 __f.__f_ = nullptr;
257 }
258 return *this;
259 }
260
261 _LIBCPP_HIDE_FROM_ABI __value_func& operator=(nullptr_t) {
262 __func* __f = __f_;
263 __f_ = nullptr;
264 if ((void*)__f == &__buf_)
265 __f->destroy();
266 else if (__f)
267 __f->destroy_deallocate();
268 return *this;
269 }
270
271 _LIBCPP_HIDE_FROM_ABI _Rp operator()(_ArgTypes&&... __args) const {
272 if (__f_ == nullptr)
273 std::__throw_bad_function_call();
274 return (*__f_)(std::forward<_ArgTypes>(__args)...);
275 }
276
277 _LIBCPP_HIDE_FROM_ABI void swap(__value_func& __f) _NOEXCEPT {
278 if (std::addressof(__f) == this)
279 return;
280 if ((void*)__f_ == &__buf_ && (void*)__f.__f_ == &__f.__buf_) {
281 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
282 typename aligned_storage<sizeof(__buf_)>::type __tempbuf;
283 _LIBCPP_SUPPRESS_DEPRECATED_POP
284 __func* __t = __as_base(&__tempbuf);
285 __f_->__clone(__t);
286 __f_->destroy();
287 __f_ = nullptr;
288 __f.__f_->__clone(__as_base(&__buf_));
289 __f.__f_->destroy();
290 __f.__f_ = nullptr;
291 __f_ = __as_base(&__buf_);
292 __t->__clone(__as_base(&__f.__buf_));
293 __t->destroy();
294 __f.__f_ = __as_base(&__f.__buf_);
295 } else if ((void*)__f_ == &__buf_) {
296 __f_->__clone(__as_base(&__f.__buf_));
297 __f_->destroy();
298 __f_ = __f.__f_;
299 __f.__f_ = __as_base(&__f.__buf_);
300 } else if ((void*)__f.__f_ == &__f.__buf_) {
301 __f.__f_->__clone(__as_base(&__buf_));
302 __f.__f_->destroy();
303 __f.__f_ = __f_;
304 __f_ = __as_base(&__buf_);
305 } else
306 std::swap(__f_, __f.__f_);
307 }
308
309 _LIBCPP_HIDE_FROM_ABI explicit operator bool() const _NOEXCEPT { return __f_ != nullptr; }
310
311# if _LIBCPP_HAS_RTTI
312 _LIBCPP_HIDE_FROM_ABI const std::type_info& target_type() const _NOEXCEPT {
313 if (__f_ == nullptr)
314 return typeid(void);
315 return __f_->target_type();
316 }
317
318 template <typename _Tp>
319 _LIBCPP_HIDE_FROM_ABI const _Tp* target() const _NOEXCEPT {
320 if (__f_ == nullptr)
321 return nullptr;
322 return (const _Tp*)__f_->target(typeid(_Tp));
323 }
324# endif // _LIBCPP_HAS_RTTI
325};
326
327// Storage for a functor object, to be used with __policy to manage copy and
328// destruction.
329union __policy_storage {
330 mutable char __small[sizeof(void*) * 2];
331 void* __large;
332};
333
334// True if _Fun can safely be held in __policy_storage.__small.
335template <typename _Fun>
336struct __use_small_storage
337 : public integral_constant<
338 bool,
339 sizeof(_Fun) <= sizeof(__policy_storage)&& _LIBCPP_ALIGNOF(_Fun) <= _LIBCPP_ALIGNOF(__policy_storage) &&
340 is_trivially_copy_constructible<_Fun>::value && is_trivially_destructible<_Fun>::value> {};
341
342// Policy contains information about how to copy, destroy, and move the
343// underlying functor. You can think of it as a vtable of sorts.
344struct __policy {
345 // Used to copy or destroy __large values. null for trivial objects.
346 void* (*const __clone)(const void*);
347 void (*const __destroy)(void*);
348
349 // True if this is the null policy (no value).
350 const bool __is_null;
351
352 // The target type. May be null if RTTI is disabled.
353 const std::type_info* const __type_info;
354
355 // Returns a pointer to a static policy object suitable for the functor
356 // type.
357 template <typename _Fun>
358 _LIBCPP_HIDE_FROM_ABI static const __policy* __create() {
359 return __choose_policy<_Fun>(__use_small_storage<_Fun>());
360 }
361
362 _LIBCPP_HIDE_FROM_ABI static const __policy* __create_empty() {
363 static constexpr __policy __policy = {
364 nullptr,
365 nullptr,
366 true,
367# if _LIBCPP_HAS_RTTI
368 &typeid(void)
369# else
370 nullptr
371# endif
372 };
373 return &__policy;
374 }
375
376private:
377 template <typename _Fun>
378 _LIBCPP_HIDE_FROM_ABI static void* __large_clone(const void* __s) {
379 const _Fun* __f = static_cast<const _Fun*>(__s);
380 return new _Fun(*__f);
381 }
382
383 template <typename _Fun>
384 _LIBCPP_HIDE_FROM_ABI static void __large_destroy(void* __s) {
385 delete static_cast<_Fun*>(__s);
386 }
387
388 template <typename _Fun>
389 _LIBCPP_HIDE_FROM_ABI static const __policy* __choose_policy(/* is_small = */ false_type) {
390 static constexpr __policy __policy = {
391 std::addressof(__large_clone<_Fun>),
392 std::addressof(__large_destroy<_Fun>),
393 false,
394# if _LIBCPP_HAS_RTTI
395 &typeid(_Fun)
396# else
397 nullptr
398# endif
399 };
400 return &__policy;
401 }
402
403 template <typename _Fun>
404 _LIBCPP_HIDE_FROM_ABI static const __policy* __choose_policy(/* is_small = */ true_type) {
405 static constexpr __policy __policy = {
406 nullptr,
407 nullptr,
408 false,
409# if _LIBCPP_HAS_RTTI
410 &typeid(_Fun)
411# else
412 nullptr
413# endif
414 };
415 return &__policy;
416 }
417};
418
419// Used to choose between perfect forwarding or pass-by-value. Pass-by-value is
420// faster for types that can be passed in registers.
421template <typename _Tp>
422using __fast_forward _LIBCPP_NODEBUG = __conditional_t<is_scalar<_Tp>::value, _Tp, _Tp&&>;
423
424// __policy_func uses a __policy to create a type-erased, copyable functor.
425
426template <class _Fp>
427class __policy_func;
428
429template <class _Rp, class... _ArgTypes>
430class __policy_func<_Rp(_ArgTypes...)> {
431 // Inline storage for small objects.
432 __policy_storage __buf_;
433
434 using _ErasedFunc _LIBCPP_NODEBUG = _Rp(const __policy_storage*, __fast_forward<_ArgTypes>...);
435
436 _ErasedFunc* __func_;
437
438 // The policy that describes how to move / copy / destroy __buf_. Never
439 // null, even if the function is empty.
440 const __policy* __policy_;
441
442 _LIBCPP_HIDE_FROM_ABI static _Rp __empty_func(const __policy_storage*, __fast_forward<_ArgTypes>...) {
443 std::__throw_bad_function_call();
444 }
445
446 template <class _Fun>
447 _LIBCPP_HIDE_FROM_ABI static _Rp __call_func(const __policy_storage* __buf, __fast_forward<_ArgTypes>... __args) {
448 _Fun* __func = reinterpret_cast<_Fun*>(__use_small_storage<_Fun>::value ? &__buf->__small : __buf->__large);
449
450 return std::__invoke_r<_Rp>(*__func, std::forward<_ArgTypes>(__args)...);
451 }
452
453public:
454 _LIBCPP_HIDE_FROM_ABI __policy_func() : __func_(__empty_func), __policy_(__policy::__create_empty()) {}
455
456 template <class _Fp, __enable_if_t<!is_same<__decay_t<_Fp>, __policy_func>::value, int> = 0>
457 _LIBCPP_HIDE_FROM_ABI explicit __policy_func(_Fp&& __f) : __policy_(__policy::__create_empty()) {
458 if (__function::__not_null(__f)) {
459 __func_ = __call_func<_Fp>;
460 __policy_ = __policy::__create<_Fp>();
461 if (__use_small_storage<_Fp>()) {
462 ::new ((void*)&__buf_.__small) _Fp(std::move(__f));
463 } else {
464 __buf_.__large = ::new _Fp(std::move(__f));
465 }
466 }
467 }
468
469 _LIBCPP_HIDE_FROM_ABI __policy_func(const __policy_func& __f)
470 : __buf_(__f.__buf_), __func_(__f.__func_), __policy_(__f.__policy_) {
471 if (__policy_->__clone)
472 __buf_.__large = __policy_->__clone(__f.__buf_.__large);
473 }
474
475 _LIBCPP_HIDE_FROM_ABI __policy_func(__policy_func&& __f)
476 : __buf_(__f.__buf_), __func_(__f.__func_), __policy_(__f.__policy_) {
477 if (__policy_->__destroy) {
478 __f.__policy_ = __policy::__create_empty();
479 __f.__func_ = {};
480 }
481 }
482
483 _LIBCPP_HIDE_FROM_ABI ~__policy_func() {
484 if (__policy_->__destroy)
485 __policy_->__destroy(__buf_.__large);
486 }
487
488 _LIBCPP_HIDE_FROM_ABI __policy_func& operator=(__policy_func&& __f) {
489 *this = nullptr;
490 __buf_ = __f.__buf_;
491 __func_ = __f.__func_;
492 __policy_ = __f.__policy_;
493 __f.__policy_ = __policy::__create_empty();
494 __f.__func_ = {};
495 return *this;
496 }
497
498 _LIBCPP_HIDE_FROM_ABI __policy_func& operator=(nullptr_t) {
499 const __policy* __p = __policy_;
500 __policy_ = __policy::__create_empty();
501 __func_ = {};
502 if (__p->__destroy)
503 __p->__destroy(__buf_.__large);
504 return *this;
505 }
506
507 _LIBCPP_HIDE_FROM_ABI _Rp operator()(_ArgTypes&&... __args) const {
508 return __func_(std::addressof(__buf_), std::forward<_ArgTypes>(__args)...);
509 }
510
511 _LIBCPP_HIDE_FROM_ABI void swap(__policy_func& __f) {
512 std::swap(__func_, __f.__func_);
513 std::swap(__policy_, __f.__policy_);
514 std::swap(__buf_, __f.__buf_);
515 }
516
517 _LIBCPP_HIDE_FROM_ABI explicit operator bool() const _NOEXCEPT { return !__policy_->__is_null; }
518
519# if _LIBCPP_HAS_RTTI
520 _LIBCPP_HIDE_FROM_ABI const std::type_info& target_type() const _NOEXCEPT { return *__policy_->__type_info; }
521
522 template <typename _Tp>
523 _LIBCPP_HIDE_FROM_ABI const _Tp* target() const _NOEXCEPT {
524 if (__policy_->__is_null || typeid(_Tp) != *__policy_->__type_info)
525 return nullptr;
526 if (__policy_->__clone) // Out of line storage.
527 return reinterpret_cast<const _Tp*>(__buf_.__large);
528 else
529 return reinterpret_cast<const _Tp*>(&__buf_.__small);
530 }
531# endif // _LIBCPP_HAS_RTTI
532};
533
534# if _LIBCPP_HAS_BLOCKS_RUNTIME
535
536extern "C" void* _Block_copy(const void*);
537extern "C" void _Block_release(const void*);
538
539template <class _Rp1, class... _ArgTypes1, class _Rp, class... _ArgTypes>
540class __func<_Rp1 (^)(_ArgTypes1...), _Rp(_ArgTypes...)> : public __base<_Rp(_ArgTypes...)> {
541 typedef _Rp1 (^__block_type)(_ArgTypes1...);
542 __block_type __f_;
543
544public:
545 _LIBCPP_HIDE_FROM_ABI explicit __func(__block_type const& __f)
546# if __has_feature(objc_arc)
547 : __f_(__f)
548# else
549 : __f_(reinterpret_cast<__block_type>(__f ? _Block_copy(__f) : nullptr))
550# endif
551 {
552 }
553
554 // [TODO] add && to save on a retain
555
556 _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual __base<_Rp(_ArgTypes...)>* __clone() const {
557 _LIBCPP_ASSERT_INTERNAL(
558 false,
559 "Block pointers are just pointers, so they should always fit into "
560 "std::function's small buffer optimization. This function should "
561 "never be invoked.");
562 return nullptr;
563 }
564
565 _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual void __clone(__base<_Rp(_ArgTypes...)>* __p) const {
566 ::new ((void*)__p) __func(__f_);
567 }
568
569 _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual void destroy() _NOEXCEPT {
570# if !__has_feature(objc_arc)
571 if (__f_)
572 _Block_release(__f_);
573# endif
574 __f_ = 0;
575 }
576
577 _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual void destroy_deallocate() _NOEXCEPT {
578 _LIBCPP_ASSERT_INTERNAL(
579 false,
580 "Block pointers are just pointers, so they should always fit into "
581 "std::function's small buffer optimization. This function should "
582 "never be invoked.");
583 }
584
585 _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual _Rp operator()(_ArgTypes&&... __arg) {
586 return std::__invoke(__f_, std::forward<_ArgTypes>(__arg)...);
587 }
588
589# if _LIBCPP_HAS_RTTI
590 _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual const void* target(type_info const& __ti) const _NOEXCEPT {
591 if (__ti == typeid(__func::__block_type))
592 return &__f_;
593 return (const void*)nullptr;
594 }
595
596 _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual const std::type_info& target_type() const _NOEXCEPT {
597 return typeid(__func::__block_type);
598 }
599# endif // _LIBCPP_HAS_RTTI
600};
601
602# endif // _LIBCPP_HAS_BLOCKS_RUNTIME
603
604} // namespace __function
605
606template <class _Rp, class... _ArgTypes>
607class function<_Rp(_ArgTypes...)>
608 : public __function::__maybe_derive_from_unary_function<_Rp(_ArgTypes...)>,
609 public __function::__maybe_derive_from_binary_function<_Rp(_ArgTypes...)> {
610# ifndef _LIBCPP_ABI_OPTIMIZED_FUNCTION
611 typedef __function::__value_func<_Rp(_ArgTypes...)> __func;
612# else
613 typedef __function::__policy_func<_Rp(_ArgTypes...)> __func;
614# endif
615
616 __func __f_;
617
618 template <class _Fp,
619 bool = _And<_IsNotSame<__remove_cvref_t<_Fp>, function>, __is_invocable<_Fp, _ArgTypes...> >::value>
620 struct __callable;
621 template <class _Fp>
622 struct __callable<_Fp, true> {
623 static const bool value =
624 is_void<_Rp>::value || __is_core_convertible<__invoke_result_t<_Fp, _ArgTypes...>, _Rp>::value;
625 };
626 template <class _Fp>
627 struct __callable<_Fp, false> {
628 static const bool value = false;
629 };
630
631 template <class _Fp>
632 using _EnableIfLValueCallable _LIBCPP_NODEBUG = __enable_if_t<__callable<_Fp&>::value>;
633
634public:
635 typedef _Rp result_type;
636
637 // construct/copy/destroy:
638 _LIBCPP_HIDE_FROM_ABI function() _NOEXCEPT {}
639 _LIBCPP_HIDE_FROM_ABI function(nullptr_t) _NOEXCEPT {}
640 _LIBCPP_HIDE_FROM_ABI function(const function&);
641 _LIBCPP_HIDE_FROM_ABI function(function&&) _NOEXCEPT;
642 template <class _Fp, class = _EnableIfLValueCallable<_Fp>>
643 _LIBCPP_HIDE_FROM_ABI function(_Fp);
644
645# if _LIBCPP_STD_VER <= 14
646 template <class _Alloc>
647 _LIBCPP_HIDE_FROM_ABI function(allocator_arg_t, const _Alloc&) _NOEXCEPT {}
648 template <class _Alloc>
649 _LIBCPP_HIDE_FROM_ABI function(allocator_arg_t, const _Alloc&, nullptr_t) _NOEXCEPT {}
650 template <class _Alloc>
651 _LIBCPP_HIDE_FROM_ABI function(allocator_arg_t, const _Alloc&, const function&);
652 template <class _Alloc>
653 _LIBCPP_HIDE_FROM_ABI function(allocator_arg_t, const _Alloc&, function&&);
654 template <class _Fp, class _Alloc, class = _EnableIfLValueCallable<_Fp>>
655 _LIBCPP_HIDE_FROM_ABI function(allocator_arg_t, const _Alloc& __a, _Fp __f);
656# endif
657
658 _LIBCPP_HIDE_FROM_ABI function& operator=(const function&);
659 _LIBCPP_HIDE_FROM_ABI function& operator=(function&&) _NOEXCEPT;
660 _LIBCPP_HIDE_FROM_ABI function& operator=(nullptr_t) _NOEXCEPT;
661 template <class _Fp, class = _EnableIfLValueCallable<__decay_t<_Fp>>>
662 _LIBCPP_HIDE_FROM_ABI function& operator=(_Fp&&);
663
664 _LIBCPP_HIDE_FROM_ABI ~function();
665
666 // function modifiers:
667 _LIBCPP_HIDE_FROM_ABI void swap(function&) _NOEXCEPT;
668
669# if _LIBCPP_STD_VER <= 14
670 template <class _Fp, class _Alloc>
671 _LIBCPP_HIDE_FROM_ABI void assign(_Fp&& __f, const _Alloc& __a) {
672 function(allocator_arg, __a, std::forward<_Fp>(__f)).swap(*this);
673 }
674# endif
675
676 // function capacity:
677 _LIBCPP_HIDE_FROM_ABI explicit operator bool() const _NOEXCEPT { return static_cast<bool>(__f_); }
678
679 // deleted overloads close possible hole in the type system
680 template <class _R2, class... _ArgTypes2>
681 bool operator==(const function<_R2(_ArgTypes2...)>&) const = delete;
682# if _LIBCPP_STD_VER <= 17
683 template <class _R2, class... _ArgTypes2>
684 bool operator!=(const function<_R2(_ArgTypes2...)>&) const = delete;
685# endif
686
687public:
688 // function invocation:
689 _LIBCPP_HIDE_FROM_ABI _Rp operator()(_ArgTypes...) const;
690
691# if _LIBCPP_HAS_RTTI
692 // function target access:
693 _LIBCPP_HIDE_FROM_ABI const std::type_info& target_type() const _NOEXCEPT;
694 template <typename _Tp>
695 _LIBCPP_HIDE_FROM_ABI _Tp* target() _NOEXCEPT;
696 template <typename _Tp>
697 _LIBCPP_HIDE_FROM_ABI const _Tp* target() const _NOEXCEPT;
698# endif // _LIBCPP_HAS_RTTI
699};
700
701# if _LIBCPP_STD_VER >= 17
702template <class _Rp, class... _Ap>
703function(_Rp (*)(_Ap...)) -> function<_Rp(_Ap...)>;
704
705template <class _Fp, class _Stripped = typename __strip_signature<decltype(&_Fp::operator())>::type>
706function(_Fp) -> function<_Stripped>;
707# endif // _LIBCPP_STD_VER >= 17
708
709template <class _Rp, class... _ArgTypes>
710function<_Rp(_ArgTypes...)>::function(const function& __f) : __f_(__f.__f_) {}
711
712# if _LIBCPP_STD_VER <= 14
713template <class _Rp, class... _ArgTypes>
714template <class _Alloc>
715function<_Rp(_ArgTypes...)>::function(allocator_arg_t, const _Alloc&, const function& __f) : __f_(__f.__f_) {}
716# endif
717
718template <class _Rp, class... _ArgTypes>
719function<_Rp(_ArgTypes...)>::function(function&& __f) _NOEXCEPT : __f_(std::move(__f.__f_)) {}
720
721# if _LIBCPP_STD_VER <= 14
722template <class _Rp, class... _ArgTypes>
723template <class _Alloc>
724function<_Rp(_ArgTypes...)>::function(allocator_arg_t, const _Alloc&, function&& __f) : __f_(std::move(__f.__f_)) {}
725# endif
726
727template <class _Rp, class... _ArgTypes>
728template <class _Fp, class>
729function<_Rp(_ArgTypes...)>::function(_Fp __f) : __f_(std::move(__f)) {}
730
731# if _LIBCPP_STD_VER <= 14
732template <class _Rp, class... _ArgTypes>
733template <class _Fp, class _Alloc, class>
734function<_Rp(_ArgTypes...)>::function(allocator_arg_t, const _Alloc&, _Fp __f) : __f_(std::move(__f)) {}
735# endif
736
737template <class _Rp, class... _ArgTypes>
738function<_Rp(_ArgTypes...)>& function<_Rp(_ArgTypes...)>::operator=(const function& __f) {
739 function(__f).swap(*this);
740 return *this;
741}
742
743template <class _Rp, class... _ArgTypes>
744function<_Rp(_ArgTypes...)>& function<_Rp(_ArgTypes...)>::operator=(function&& __f) _NOEXCEPT {
745 __f_ = std::move(__f.__f_);
746 return *this;
747}
748
749template <class _Rp, class... _ArgTypes>
750function<_Rp(_ArgTypes...)>& function<_Rp(_ArgTypes...)>::operator=(nullptr_t) _NOEXCEPT {
751 __f_ = nullptr;
752 return *this;
753}
754
755template <class _Rp, class... _ArgTypes>
756template <class _Fp, class>
757function<_Rp(_ArgTypes...)>& function<_Rp(_ArgTypes...)>::operator=(_Fp&& __f) {
758 function(std::forward<_Fp>(__f)).swap(*this);
759 return *this;
760}
761
762template <class _Rp, class... _ArgTypes>
763function<_Rp(_ArgTypes...)>::~function() {}
764
765template <class _Rp, class... _ArgTypes>
766void function<_Rp(_ArgTypes...)>::swap(function& __f) _NOEXCEPT {
767 __f_.swap(__f.__f_);
768}
769
770template <class _Rp, class... _ArgTypes>
771_Rp function<_Rp(_ArgTypes...)>::operator()(_ArgTypes... __arg) const {
772 return __f_(std::forward<_ArgTypes>(__arg)...);
773}
774
775# if _LIBCPP_HAS_RTTI
776
777template <class _Rp, class... _ArgTypes>
778const std::type_info& function<_Rp(_ArgTypes...)>::target_type() const _NOEXCEPT {
779 return __f_.target_type();
780}
781
782template <class _Rp, class... _ArgTypes>
783template <typename _Tp>
784_Tp* function<_Rp(_ArgTypes...)>::target() _NOEXCEPT {
785 return (_Tp*)(__f_.template target<_Tp>());
786}
787
788template <class _Rp, class... _ArgTypes>
789template <typename _Tp>
790const _Tp* function<_Rp(_ArgTypes...)>::target() const _NOEXCEPT {
791 return __f_.template target<_Tp>();
792}
793
794# endif // _LIBCPP_HAS_RTTI
795
796template <class _Rp, class... _ArgTypes>
797inline _LIBCPP_HIDE_FROM_ABI bool operator==(const function<_Rp(_ArgTypes...)>& __f, nullptr_t) _NOEXCEPT {
798 return !__f;
799}
800
801# if _LIBCPP_STD_VER <= 17
802
803template <class _Rp, class... _ArgTypes>
804inline _LIBCPP_HIDE_FROM_ABI bool operator==(nullptr_t, const function<_Rp(_ArgTypes...)>& __f) _NOEXCEPT {
805 return !__f;
806}
807
808template <class _Rp, class... _ArgTypes>
809inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const function<_Rp(_ArgTypes...)>& __f, nullptr_t) _NOEXCEPT {
810 return (bool)__f;
811}
812
813template <class _Rp, class... _ArgTypes>
814inline _LIBCPP_HIDE_FROM_ABI bool operator!=(nullptr_t, const function<_Rp(_ArgTypes...)>& __f) _NOEXCEPT {
815 return (bool)__f;
816}
817
818# endif // _LIBCPP_STD_VER <= 17
819
820template <class _Rp, class... _ArgTypes>
821inline _LIBCPP_HIDE_FROM_ABI void swap(function<_Rp(_ArgTypes...)>& __x, function<_Rp(_ArgTypes...)>& __y) _NOEXCEPT {
822 return __x.swap(__y);
823}
824
825_LIBCPP_END_NAMESPACE_STD
826
827#endif // _LIBCPP_CXX03_LANG
828
829_LIBCPP_POP_MACROS
830
831#endif // _LIBCPP___FUNCTIONAL_FUNCTION_H