1// <functional> -*- C++ -*-
2
3// Copyright (C) 2001-2015 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library. This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14// GNU General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23// <http://www.gnu.org/licenses/>.
24
25/*
26 * Copyright (c) 1997
27 * Silicon Graphics Computer Systems, Inc.
28 *
29 * Permission to use, copy, modify, distribute and sell this software
30 * and its documentation for any purpose is hereby granted without fee,
31 * provided that the above copyright notice appear in all copies and
32 * that both that copyright notice and this permission notice appear
33 * in supporting documentation. Silicon Graphics makes no
34 * representations about the suitability of this software for any
35 * purpose. It is provided "as is" without express or implied warranty.
36 *
37 */
38
39/** @file include/functional
40 * This is a Standard C++ Library header.
41 */
42
43#ifndef _GLIBCXX_FUNCTIONAL
44#define _GLIBCXX_FUNCTIONAL 1
45
46#pragma GCC system_header
47
48#include <bits/c++config.h>
49#include <bits/stl_function.h>
50
51#if __cplusplus >= 201103L
52
53#include <typeinfo>
54#include <new>
55#include <tuple>
56#include <type_traits>
57#include <bits/functexcept.h>
58#include <bits/functional_hash.h>
59
60namespace std _GLIBCXX_VISIBILITY(default)
61{
62_GLIBCXX_BEGIN_NAMESPACE_VERSION
63
64 template<typename _MemberPointer>
65 class _Mem_fn;
66 template<typename _Tp, typename _Class>
67 _Mem_fn<_Tp _Class::*>
68 mem_fn(_Tp _Class::*) noexcept;
69
70 /// If we have found a result_type, extract it.
71 template<typename _Functor, typename = __void_t<>>
72 struct _Maybe_get_result_type
73 { };
74
75 template<typename _Functor>
76 struct _Maybe_get_result_type<_Functor,
77 __void_t<typename _Functor::result_type>>
78 { typedef typename _Functor::result_type result_type; };
79
80 /**
81 * Base class for any function object that has a weak result type, as
82 * defined in 20.8.2 [func.require] of C++11.
83 */
84 template<typename _Functor>
85 struct _Weak_result_type_impl
86 : _Maybe_get_result_type<_Functor>
87 { };
88
89 /// Retrieve the result type for a function type.
90 template<typename _Res, typename... _ArgTypes>
91 struct _Weak_result_type_impl<_Res(_ArgTypes...)>
92 { typedef _Res result_type; };
93
94 template<typename _Res, typename... _ArgTypes>
95 struct _Weak_result_type_impl<_Res(_ArgTypes......)>
96 { typedef _Res result_type; };
97
98 template<typename _Res, typename... _ArgTypes>
99 struct _Weak_result_type_impl<_Res(_ArgTypes...) const>
100 { typedef _Res result_type; };
101
102 template<typename _Res, typename... _ArgTypes>
103 struct _Weak_result_type_impl<_Res(_ArgTypes......) const>
104 { typedef _Res result_type; };
105
106 template<typename _Res, typename... _ArgTypes>
107 struct _Weak_result_type_impl<_Res(_ArgTypes...) volatile>
108 { typedef _Res result_type; };
109
110 template<typename _Res, typename... _ArgTypes>
111 struct _Weak_result_type_impl<_Res(_ArgTypes......) volatile>
112 { typedef _Res result_type; };
113
114 template<typename _Res, typename... _ArgTypes>
115 struct _Weak_result_type_impl<_Res(_ArgTypes...) const volatile>
116 { typedef _Res result_type; };
117
118 template<typename _Res, typename... _ArgTypes>
119 struct _Weak_result_type_impl<_Res(_ArgTypes......) const volatile>
120 { typedef _Res result_type; };
121
122 /// Retrieve the result type for a function reference.
123 template<typename _Res, typename... _ArgTypes>
124 struct _Weak_result_type_impl<_Res(&)(_ArgTypes...)>
125 { typedef _Res result_type; };
126
127 template<typename _Res, typename... _ArgTypes>
128 struct _Weak_result_type_impl<_Res(&)(_ArgTypes......)>
129 { typedef _Res result_type; };
130
131 /// Retrieve the result type for a function pointer.
132 template<typename _Res, typename... _ArgTypes>
133 struct _Weak_result_type_impl<_Res(*)(_ArgTypes...)>
134 { typedef _Res result_type; };
135
136 template<typename _Res, typename... _ArgTypes>
137 struct _Weak_result_type_impl<_Res(*)(_ArgTypes......)>
138 { typedef _Res result_type; };
139
140 /// Retrieve result type for a member function pointer.
141 template<typename _Res, typename _Class, typename... _ArgTypes>
142 struct _Weak_result_type_impl<_Res (_Class::*)(_ArgTypes...)>
143 { typedef _Res result_type; };
144
145 template<typename _Res, typename _Class, typename... _ArgTypes>
146 struct _Weak_result_type_impl<_Res (_Class::*)(_ArgTypes......)>
147 { typedef _Res result_type; };
148
149 /// Retrieve result type for a const member function pointer.
150 template<typename _Res, typename _Class, typename... _ArgTypes>
151 struct _Weak_result_type_impl<_Res (_Class::*)(_ArgTypes...) const>
152 { typedef _Res result_type; };
153
154 template<typename _Res, typename _Class, typename... _ArgTypes>
155 struct _Weak_result_type_impl<_Res (_Class::*)(_ArgTypes......) const>
156 { typedef _Res result_type; };
157
158 /// Retrieve result type for a volatile member function pointer.
159 template<typename _Res, typename _Class, typename... _ArgTypes>
160 struct _Weak_result_type_impl<_Res (_Class::*)(_ArgTypes...) volatile>
161 { typedef _Res result_type; };
162
163 template<typename _Res, typename _Class, typename... _ArgTypes>
164 struct _Weak_result_type_impl<_Res (_Class::*)(_ArgTypes......) volatile>
165 { typedef _Res result_type; };
166
167 /// Retrieve result type for a const volatile member function pointer.
168 template<typename _Res, typename _Class, typename... _ArgTypes>
169 struct _Weak_result_type_impl<_Res (_Class::*)(_ArgTypes...)
170 const volatile>
171 { typedef _Res result_type; };
172
173 template<typename _Res, typename _Class, typename... _ArgTypes>
174 struct _Weak_result_type_impl<_Res (_Class::*)(_ArgTypes......)
175 const volatile>
176 { typedef _Res result_type; };
177
178 /**
179 * Strip top-level cv-qualifiers from the function object and let
180 * _Weak_result_type_impl perform the real work.
181 */
182 template<typename _Functor>
183 struct _Weak_result_type
184 : _Weak_result_type_impl<typename remove_cv<_Functor>::type>
185 { };
186
187 /**
188 * Invoke a function object, which may be either a member pointer or a
189 * function object. The first parameter will tell which.
190 */
191 template<typename _Functor, typename... _Args>
192 inline
193 typename enable_if<
194 (!is_member_pointer<_Functor>::value
195 && !is_function<_Functor>::value
196 && !is_function<typename remove_pointer<_Functor>::type>::value),
197 typename result_of<_Functor&(_Args&&...)>::type
198 >::type
199 __invoke(_Functor& __f, _Args&&... __args)
200 {
201 return __f(std::forward<_Args>(__args)...);
202 }
203
204 template<typename _Functor, typename... _Args>
205 inline
206 typename enable_if<
207 (is_member_pointer<_Functor>::value
208 && !is_function<_Functor>::value
209 && !is_function<typename remove_pointer<_Functor>::type>::value),
210 typename result_of<_Functor(_Args&&...)>::type
211 >::type
212 __invoke(_Functor& __f, _Args&&... __args)
213 {
214 return std::mem_fn(__f)(std::forward<_Args>(__args)...);
215 }
216
217 // To pick up function references (that will become function pointers)
218 template<typename _Functor, typename... _Args>
219 inline
220 typename enable_if<
221 (is_pointer<_Functor>::value
222 && is_function<typename remove_pointer<_Functor>::type>::value),
223 typename result_of<_Functor(_Args&&...)>::type
224 >::type
225 __invoke(_Functor __f, _Args&&... __args)
226 {
227 return __f(std::forward<_Args>(__args)...);
228 }
229
230 /**
231 * Knowing which of unary_function and binary_function _Tp derives
232 * from, derives from the same and ensures that reference_wrapper
233 * will have a weak result type. See cases below.
234 */
235 template<bool _Unary, bool _Binary, typename _Tp>
236 struct _Reference_wrapper_base_impl;
237
238 // None of the nested argument types.
239 template<typename _Tp>
240 struct _Reference_wrapper_base_impl<false, false, _Tp>
241 : _Weak_result_type<_Tp>
242 { };
243
244 // Nested argument_type only.
245 template<typename _Tp>
246 struct _Reference_wrapper_base_impl<true, false, _Tp>
247 : _Weak_result_type<_Tp>
248 {
249 typedef typename _Tp::argument_type argument_type;
250 };
251
252 // Nested first_argument_type and second_argument_type only.
253 template<typename _Tp>
254 struct _Reference_wrapper_base_impl<false, true, _Tp>
255 : _Weak_result_type<_Tp>
256 {
257 typedef typename _Tp::first_argument_type first_argument_type;
258 typedef typename _Tp::second_argument_type second_argument_type;
259 };
260
261 // All the nested argument types.
262 template<typename _Tp>
263 struct _Reference_wrapper_base_impl<true, true, _Tp>
264 : _Weak_result_type<_Tp>
265 {
266 typedef typename _Tp::argument_type argument_type;
267 typedef typename _Tp::first_argument_type first_argument_type;
268 typedef typename _Tp::second_argument_type second_argument_type;
269 };
270
271 _GLIBCXX_HAS_NESTED_TYPE(argument_type)
272 _GLIBCXX_HAS_NESTED_TYPE(first_argument_type)
273 _GLIBCXX_HAS_NESTED_TYPE(second_argument_type)
274
275 /**
276 * Derives from unary_function or binary_function when it
277 * can. Specializations handle all of the easy cases. The primary
278 * template determines what to do with a class type, which may
279 * derive from both unary_function and binary_function.
280 */
281 template<typename _Tp>
282 struct _Reference_wrapper_base
283 : _Reference_wrapper_base_impl<
284 __has_argument_type<_Tp>::value,
285 __has_first_argument_type<_Tp>::value
286 && __has_second_argument_type<_Tp>::value,
287 _Tp>
288 { };
289
290 // - a function type (unary)
291 template<typename _Res, typename _T1>
292 struct _Reference_wrapper_base<_Res(_T1)>
293 : unary_function<_T1, _Res>
294 { };
295
296 template<typename _Res, typename _T1>
297 struct _Reference_wrapper_base<_Res(_T1) const>
298 : unary_function<_T1, _Res>
299 { };
300
301 template<typename _Res, typename _T1>
302 struct _Reference_wrapper_base<_Res(_T1) volatile>
303 : unary_function<_T1, _Res>
304 { };
305
306 template<typename _Res, typename _T1>
307 struct _Reference_wrapper_base<_Res(_T1) const volatile>
308 : unary_function<_T1, _Res>
309 { };
310
311 // - a function type (binary)
312 template<typename _Res, typename _T1, typename _T2>
313 struct _Reference_wrapper_base<_Res(_T1, _T2)>
314 : binary_function<_T1, _T2, _Res>
315 { };
316
317 template<typename _Res, typename _T1, typename _T2>
318 struct _Reference_wrapper_base<_Res(_T1, _T2) const>
319 : binary_function<_T1, _T2, _Res>
320 { };
321
322 template<typename _Res, typename _T1, typename _T2>
323 struct _Reference_wrapper_base<_Res(_T1, _T2) volatile>
324 : binary_function<_T1, _T2, _Res>
325 { };
326
327 template<typename _Res, typename _T1, typename _T2>
328 struct _Reference_wrapper_base<_Res(_T1, _T2) const volatile>
329 : binary_function<_T1, _T2, _Res>
330 { };
331
332 // - a function pointer type (unary)
333 template<typename _Res, typename _T1>
334 struct _Reference_wrapper_base<_Res(*)(_T1)>
335 : unary_function<_T1, _Res>
336 { };
337
338 // - a function pointer type (binary)
339 template<typename _Res, typename _T1, typename _T2>
340 struct _Reference_wrapper_base<_Res(*)(_T1, _T2)>
341 : binary_function<_T1, _T2, _Res>
342 { };
343
344 // - a pointer to member function type (unary, no qualifiers)
345 template<typename _Res, typename _T1>
346 struct _Reference_wrapper_base<_Res (_T1::*)()>
347 : unary_function<_T1*, _Res>
348 { };
349
350 // - a pointer to member function type (binary, no qualifiers)
351 template<typename _Res, typename _T1, typename _T2>
352 struct _Reference_wrapper_base<_Res (_T1::*)(_T2)>
353 : binary_function<_T1*, _T2, _Res>
354 { };
355
356 // - a pointer to member function type (unary, const)
357 template<typename _Res, typename _T1>
358 struct _Reference_wrapper_base<_Res (_T1::*)() const>
359 : unary_function<const _T1*, _Res>
360 { };
361
362 // - a pointer to member function type (binary, const)
363 template<typename _Res, typename _T1, typename _T2>
364 struct _Reference_wrapper_base<_Res (_T1::*)(_T2) const>
365 : binary_function<const _T1*, _T2, _Res>
366 { };
367
368 // - a pointer to member function type (unary, volatile)
369 template<typename _Res, typename _T1>
370 struct _Reference_wrapper_base<_Res (_T1::*)() volatile>
371 : unary_function<volatile _T1*, _Res>
372 { };
373
374 // - a pointer to member function type (binary, volatile)
375 template<typename _Res, typename _T1, typename _T2>
376 struct _Reference_wrapper_base<_Res (_T1::*)(_T2) volatile>
377 : binary_function<volatile _T1*, _T2, _Res>
378 { };
379
380 // - a pointer to member function type (unary, const volatile)
381 template<typename _Res, typename _T1>
382 struct _Reference_wrapper_base<_Res (_T1::*)() const volatile>
383 : unary_function<const volatile _T1*, _Res>
384 { };
385
386 // - a pointer to member function type (binary, const volatile)
387 template<typename _Res, typename _T1, typename _T2>
388 struct _Reference_wrapper_base<_Res (_T1::*)(_T2) const volatile>
389 : binary_function<const volatile _T1*, _T2, _Res>
390 { };
391
392 /**
393 * @brief Primary class template for reference_wrapper.
394 * @ingroup functors
395 * @{
396 */
397 template<typename _Tp>
398 class reference_wrapper
399 : public _Reference_wrapper_base<typename remove_cv<_Tp>::type>
400 {
401 _Tp* _M_data;
402
403 public:
404 typedef _Tp type;
405
406 reference_wrapper(_Tp& __indata) noexcept
407 : _M_data(std::__addressof(__indata))
408 { }
409
410 reference_wrapper(_Tp&&) = delete;
411
412 reference_wrapper(const reference_wrapper&) = default;
413
414 reference_wrapper&
415 operator=(const reference_wrapper&) = default;
416
417 operator _Tp&() const noexcept
418 { return this->get(); }
419
420 _Tp&
421 get() const noexcept
422 { return *_M_data; }
423
424 template<typename... _Args>
425 typename result_of<_Tp&(_Args&&...)>::type
426 operator()(_Args&&... __args) const
427 {
428 return __invoke(get(), std::forward<_Args>(__args)...);
429 }
430 };
431
432
433 /// Denotes a reference should be taken to a variable.
434 template<typename _Tp>
435 inline reference_wrapper<_Tp>
436 ref(_Tp& __t) noexcept
437 { return reference_wrapper<_Tp>(__t); }
438
439 /// Denotes a const reference should be taken to a variable.
440 template<typename _Tp>
441 inline reference_wrapper<const _Tp>
442 cref(const _Tp& __t) noexcept
443 { return reference_wrapper<const _Tp>(__t); }
444
445 template<typename _Tp>
446 void ref(const _Tp&&) = delete;
447
448 template<typename _Tp>
449 void cref(const _Tp&&) = delete;
450
451 /// Partial specialization.
452 template<typename _Tp>
453 inline reference_wrapper<_Tp>
454 ref(reference_wrapper<_Tp> __t) noexcept
455 { return ref(__t.get()); }
456
457 /// Partial specialization.
458 template<typename _Tp>
459 inline reference_wrapper<const _Tp>
460 cref(reference_wrapper<_Tp> __t) noexcept
461 { return cref(__t.get()); }
462
463 // @} group functors
464
465 template<typename... _Types>
466 struct _Pack : integral_constant<size_t, sizeof...(_Types)>
467 { };
468
469 template<typename _From, typename _To, bool = _From::value == _To::value>
470 struct _AllConvertible : false_type
471 { };
472
473 template<typename... _From, typename... _To>
474 struct _AllConvertible<_Pack<_From...>, _Pack<_To...>, true>
475 : __and_<is_convertible<_From, _To>...>
476 { };
477
478 template<typename _Tp1, typename _Tp2>
479 using _NotSame = __not_<is_same<typename std::decay<_Tp1>::type,
480 typename std::decay<_Tp2>::type>>;
481
482 /**
483 * Derives from @c unary_function or @c binary_function, or perhaps
484 * nothing, depending on the number of arguments provided. The
485 * primary template is the basis case, which derives nothing.
486 */
487 template<typename _Res, typename... _ArgTypes>
488 struct _Maybe_unary_or_binary_function { };
489
490 /// Derives from @c unary_function, as appropriate.
491 template<typename _Res, typename _T1>
492 struct _Maybe_unary_or_binary_function<_Res, _T1>
493 : std::unary_function<_T1, _Res> { };
494
495 /// Derives from @c binary_function, as appropriate.
496 template<typename _Res, typename _T1, typename _T2>
497 struct _Maybe_unary_or_binary_function<_Res, _T1, _T2>
498 : std::binary_function<_T1, _T2, _Res> { };
499
500 template<typename _Signature>
501 struct _Mem_fn_traits;
502
503 template<typename _Res, typename _Class, typename... _ArgTypes>
504 struct _Mem_fn_traits_base
505 {
506 using __result_type = _Res;
507 using __class_type = _Class;
508 using __arg_types = _Pack<_ArgTypes...>;
509 using __maybe_type
510 = _Maybe_unary_or_binary_function<_Res, _Class*, _ArgTypes...>;
511 using __arity = integral_constant<size_t, sizeof...(_ArgTypes)>;
512 };
513
514#define _GLIBCXX_MEM_FN_TRAITS2(_CV, _REF, _LVAL, _RVAL) \
515 template<typename _Res, typename _Class, typename... _ArgTypes> \
516 struct _Mem_fn_traits<_Res (_Class::*)(_ArgTypes...) _CV _REF> \
517 : _Mem_fn_traits_base<_Res, _CV _Class, _ArgTypes...> \
518 { \
519 using __pmf_type = _Res (_Class::*)(_ArgTypes...) _CV _REF; \
520 using __lvalue = _LVAL; \
521 using __rvalue = _RVAL; \
522 using __vararg = false_type; \
523 }; \
524 template<typename _Res, typename _Class, typename... _ArgTypes> \
525 struct _Mem_fn_traits<_Res (_Class::*)(_ArgTypes... ...) _CV _REF> \
526 : _Mem_fn_traits_base<_Res, _CV _Class, _ArgTypes...> \
527 { \
528 using __pmf_type = _Res (_Class::*)(_ArgTypes... ...) _CV _REF; \
529 using __lvalue = _LVAL; \
530 using __rvalue = _RVAL; \
531 using __vararg = true_type; \
532 };
533
534#define _GLIBCXX_MEM_FN_TRAITS(_REF, _LVAL, _RVAL) \
535 _GLIBCXX_MEM_FN_TRAITS2( , _REF, _LVAL, _RVAL) \
536 _GLIBCXX_MEM_FN_TRAITS2(const , _REF, _LVAL, _RVAL) \
537 _GLIBCXX_MEM_FN_TRAITS2(volatile , _REF, _LVAL, _RVAL) \
538 _GLIBCXX_MEM_FN_TRAITS2(const volatile, _REF, _LVAL, _RVAL)
539
540_GLIBCXX_MEM_FN_TRAITS( , true_type, true_type)
541_GLIBCXX_MEM_FN_TRAITS(&, true_type, false_type)
542_GLIBCXX_MEM_FN_TRAITS(&&, false_type, true_type)
543
544#undef _GLIBCXX_MEM_FN_TRAITS
545#undef _GLIBCXX_MEM_FN_TRAITS2
546
547 template<typename _MemFunPtr,
548 bool __is_mem_fn = is_member_function_pointer<_MemFunPtr>::value>
549 class _Mem_fn_base
550 : public _Mem_fn_traits<_MemFunPtr>::__maybe_type
551 {
552 using _Traits = _Mem_fn_traits<_MemFunPtr>;
553
554 using _Class = typename _Traits::__class_type;
555 using _ArgTypes = typename _Traits::__arg_types;
556 using _Pmf = typename _Traits::__pmf_type;
557
558 using _Arity = typename _Traits::__arity;
559 using _Varargs = typename _Traits::__vararg;
560
561 template<typename _Func, typename... _BoundArgs>
562 friend struct _Bind_check_arity;
563
564 // for varargs functions we just check the number of arguments,
565 // otherwise we also check they are convertible.
566 template<typename _Args>
567 using _CheckArgs = typename conditional<_Varargs::value,
568 __bool_constant<(_Args::value >= _ArgTypes::value)>,
569 _AllConvertible<_Args, _ArgTypes>
570 >::type;
571
572 public:
573 using result_type = typename _Traits::__result_type;
574
575 explicit _Mem_fn_base(_Pmf __pmf) : _M_pmf(__pmf) { }
576
577 // Handle objects
578 template<typename... _Args, typename _Req
579 = _Require<typename _Traits::__lvalue,
580 _CheckArgs<_Pack<_Args...>>>>
581 result_type
582 operator()(_Class& __object, _Args&&... __args) const
583 { return (__object.*_M_pmf)(std::forward<_Args>(__args)...); }
584
585 template<typename... _Args, typename _Req
586 = _Require<typename _Traits::__rvalue,
587 _CheckArgs<_Pack<_Args...>>>>
588 result_type
589 operator()(_Class&& __object, _Args&&... __args) const
590 {
591 return (std::move(__object).*_M_pmf)(std::forward<_Args>(__args)...);
592 }
593
594 // Handle pointers
595 template<typename... _Args, typename _Req
596 = _Require<typename _Traits::__lvalue,
597 _CheckArgs<_Pack<_Args...>>>>
598 result_type
599 operator()(_Class* __object, _Args&&... __args) const
600 { return (__object->*_M_pmf)(std::forward<_Args>(__args)...); }
601
602 // Handle smart pointers, references and pointers to derived
603 template<typename _Tp, typename... _Args, typename _Req
604 = _Require<_NotSame<_Class, _Tp>, _NotSame<_Class*, _Tp>,
605 _CheckArgs<_Pack<_Args...>>>>
606 result_type
607 operator()(_Tp&& __object, _Args&&... __args) const
608 {
609 return _M_call(std::forward<_Tp>(__object), &__object,
610 std::forward<_Args>(__args)...);
611 }
612
613 // Handle reference wrappers
614 template<typename _Tp, typename... _Args, typename _Req
615 = _Require<is_base_of<_Class, _Tp>, typename _Traits::__lvalue,
616 _CheckArgs<_Pack<_Args...>>>>
617 result_type
618 operator()(reference_wrapper<_Tp> __ref, _Args&&... __args) const
619 { return operator()(__ref.get(), std::forward<_Args>(__args)...); }
620
621 private:
622 template<typename _Tp, typename... _Args>
623 result_type
624 _M_call(_Tp&& __object, const volatile _Class *,
625 _Args&&... __args) const
626 {
627 return (std::forward<_Tp>(__object).*_M_pmf)
628 (std::forward<_Args>(__args)...);
629 }
630
631 template<typename _Tp, typename... _Args>
632 result_type
633 _M_call(_Tp&& __ptr, const volatile void *, _Args&&... __args) const
634 { return ((*__ptr).*_M_pmf)(std::forward<_Args>(__args)...); }
635
636 _Pmf _M_pmf;
637 };
638
639 // Partial specialization for member object pointers.
640 template<typename _Res, typename _Class>
641 class _Mem_fn_base<_Res _Class::*, false>
642 {
643 using __pm_type = _Res _Class::*;
644
645 // This bit of genius is due to Peter Dimov, improved slightly by
646 // Douglas Gregor.
647 // Made less elegant to support perfect forwarding and noexcept.
648 template<typename _Tp>
649 auto
650 _M_call(_Tp&& __object, const _Class *) const noexcept
651 -> decltype(std::forward<_Tp>(__object).*std::declval<__pm_type&>())
652 { return std::forward<_Tp>(__object).*_M_pm; }
653
654 template<typename _Tp, typename _Up>
655 auto
656 _M_call(_Tp&& __object, _Up * const *) const noexcept
657 -> decltype((*std::forward<_Tp>(__object)).*std::declval<__pm_type&>())
658 { return (*std::forward<_Tp>(__object)).*_M_pm; }
659
660 template<typename _Tp>
661 auto
662 _M_call(_Tp&& __ptr, const volatile void*) const
663 noexcept(noexcept((*__ptr).*std::declval<__pm_type&>()))
664 -> decltype((*__ptr).*std::declval<__pm_type&>())
665 { return (*__ptr).*_M_pm; }
666
667 using _Arity = integral_constant<size_t, 0>;
668 using _Varargs = false_type;
669
670 template<typename _Func, typename... _BoundArgs>
671 friend struct _Bind_check_arity;
672
673 public:
674 explicit
675 _Mem_fn_base(_Res _Class::*__pm) noexcept : _M_pm(__pm) { }
676
677 // Handle objects
678 _Res&
679 operator()(_Class& __object) const noexcept
680 { return __object.*_M_pm; }
681
682 const _Res&
683 operator()(const _Class& __object) const noexcept
684 { return __object.*_M_pm; }
685
686 _Res&&
687 operator()(_Class&& __object) const noexcept
688 { return std::forward<_Class>(__object).*_M_pm; }
689
690 const _Res&&
691 operator()(const _Class&& __object) const noexcept
692 { return std::forward<const _Class>(__object).*_M_pm; }
693
694 // Handle pointers
695 _Res&
696 operator()(_Class* __object) const noexcept
697 { return __object->*_M_pm; }
698
699 const _Res&
700 operator()(const _Class* __object) const noexcept
701 { return __object->*_M_pm; }
702
703 // Handle smart pointers and derived
704 template<typename _Tp, typename _Req = _Require<_NotSame<_Class*, _Tp>>>
705 auto
706 operator()(_Tp&& __unknown) const
707 noexcept(noexcept(std::declval<_Mem_fn_base*>()->_M_call
708 (std::forward<_Tp>(__unknown), &__unknown)))
709 -> decltype(this->_M_call(std::forward<_Tp>(__unknown), &__unknown))
710 { return _M_call(std::forward<_Tp>(__unknown), &__unknown); }
711
712 template<typename _Tp, typename _Req = _Require<is_base_of<_Class, _Tp>>>
713 auto
714 operator()(reference_wrapper<_Tp> __ref) const
715 noexcept(noexcept(std::declval<_Mem_fn_base&>()(__ref.get())))
716 -> decltype((*this)(__ref.get()))
717 { return (*this)(__ref.get()); }
718
719 private:
720 _Res _Class::*_M_pm;
721 };
722
723 template<typename _Res, typename _Class>
724 struct _Mem_fn<_Res _Class::*>
725 : _Mem_fn_base<_Res _Class::*>
726 {
727 using _Mem_fn_base<_Res _Class::*>::_Mem_fn_base;
728 };
729
730 // _GLIBCXX_RESOLVE_LIB_DEFECTS
731 // 2048. Unnecessary mem_fn overloads
732 /**
733 * @brief Returns a function object that forwards to the member
734 * pointer @a pm.
735 * @ingroup functors
736 */
737 template<typename _Tp, typename _Class>
738 inline _Mem_fn<_Tp _Class::*>
739 mem_fn(_Tp _Class::* __pm) noexcept
740 {
741 return _Mem_fn<_Tp _Class::*>(__pm);
742 }
743
744 /**
745 * @brief Determines if the given type _Tp is a function object
746 * should be treated as a subexpression when evaluating calls to
747 * function objects returned by bind(). [TR1 3.6.1]
748 * @ingroup binders
749 */
750 template<typename _Tp>
751 struct is_bind_expression
752 : public false_type { };
753
754 /**
755 * @brief Determines if the given type _Tp is a placeholder in a
756 * bind() expression and, if so, which placeholder it is. [TR1 3.6.2]
757 * @ingroup binders
758 */
759 template<typename _Tp>
760 struct is_placeholder
761 : public integral_constant<int, 0>
762 { };
763
764 /** @brief The type of placeholder objects defined by libstdc++.
765 * @ingroup binders
766 */
767 template<int _Num> struct _Placeholder { };
768
769 _GLIBCXX_END_NAMESPACE_VERSION
770
771 /** @namespace std::placeholders
772 * @brief ISO C++11 entities sub-namespace for functional.
773 * @ingroup binders
774 */
775 namespace placeholders
776 {
777 _GLIBCXX_BEGIN_NAMESPACE_VERSION
778 /* Define a large number of placeholders. There is no way to
779 * simplify this with variadic templates, because we're introducing
780 * unique names for each.
781 */
782 extern const _Placeholder<1> _1;
783 extern const _Placeholder<2> _2;
784 extern const _Placeholder<3> _3;
785 extern const _Placeholder<4> _4;
786 extern const _Placeholder<5> _5;
787 extern const _Placeholder<6> _6;
788 extern const _Placeholder<7> _7;
789 extern const _Placeholder<8> _8;
790 extern const _Placeholder<9> _9;
791 extern const _Placeholder<10> _10;
792 extern const _Placeholder<11> _11;
793 extern const _Placeholder<12> _12;
794 extern const _Placeholder<13> _13;
795 extern const _Placeholder<14> _14;
796 extern const _Placeholder<15> _15;
797 extern const _Placeholder<16> _16;
798 extern const _Placeholder<17> _17;
799 extern const _Placeholder<18> _18;
800 extern const _Placeholder<19> _19;
801 extern const _Placeholder<20> _20;
802 extern const _Placeholder<21> _21;
803 extern const _Placeholder<22> _22;
804 extern const _Placeholder<23> _23;
805 extern const _Placeholder<24> _24;
806 extern const _Placeholder<25> _25;
807 extern const _Placeholder<26> _26;
808 extern const _Placeholder<27> _27;
809 extern const _Placeholder<28> _28;
810 extern const _Placeholder<29> _29;
811 _GLIBCXX_END_NAMESPACE_VERSION
812 }
813
814 _GLIBCXX_BEGIN_NAMESPACE_VERSION
815
816 /**
817 * Partial specialization of is_placeholder that provides the placeholder
818 * number for the placeholder objects defined by libstdc++.
819 * @ingroup binders
820 */
821 template<int _Num>
822 struct is_placeholder<_Placeholder<_Num> >
823 : public integral_constant<int, _Num>
824 { };
825
826 template<int _Num>
827 struct is_placeholder<const _Placeholder<_Num> >
828 : public integral_constant<int, _Num>
829 { };
830
831 /**
832 * Used by _Safe_tuple_element to indicate that there is no tuple
833 * element at this position.
834 */
835 struct _No_tuple_element;
836
837 /**
838 * Implementation helper for _Safe_tuple_element. This primary
839 * template handles the case where it is safe to use @c
840 * tuple_element.
841 */
842 template<std::size_t __i, typename _Tuple, bool _IsSafe>
843 struct _Safe_tuple_element_impl
844 : tuple_element<__i, _Tuple> { };
845
846 /**
847 * Implementation helper for _Safe_tuple_element. This partial
848 * specialization handles the case where it is not safe to use @c
849 * tuple_element. We just return @c _No_tuple_element.
850 */
851 template<std::size_t __i, typename _Tuple>
852 struct _Safe_tuple_element_impl<__i, _Tuple, false>
853 {
854 typedef _No_tuple_element type;
855 };
856
857 /**
858 * Like tuple_element, but returns @c _No_tuple_element when
859 * tuple_element would return an error.
860 */
861 template<std::size_t __i, typename _Tuple>
862 struct _Safe_tuple_element
863 : _Safe_tuple_element_impl<__i, _Tuple,
864 (__i < tuple_size<_Tuple>::value)>
865 { };
866
867 /**
868 * Maps an argument to bind() into an actual argument to the bound
869 * function object [TR1 3.6.3/5]. Only the first parameter should
870 * be specified: the rest are used to determine among the various
871 * implementations. Note that, although this class is a function
872 * object, it isn't entirely normal because it takes only two
873 * parameters regardless of the number of parameters passed to the
874 * bind expression. The first parameter is the bound argument and
875 * the second parameter is a tuple containing references to the
876 * rest of the arguments.
877 */
878 template<typename _Arg,
879 bool _IsBindExp = is_bind_expression<_Arg>::value,
880 bool _IsPlaceholder = (is_placeholder<_Arg>::value > 0)>
881 class _Mu;
882
883 /**
884 * If the argument is reference_wrapper<_Tp>, returns the
885 * underlying reference. [TR1 3.6.3/5 bullet 1]
886 */
887 template<typename _Tp>
888 class _Mu<reference_wrapper<_Tp>, false, false>
889 {
890 public:
891 typedef _Tp& result_type;
892
893 /* Note: This won't actually work for const volatile
894 * reference_wrappers, because reference_wrapper::get() is const
895 * but not volatile-qualified. This might be a defect in the TR.
896 */
897 template<typename _CVRef, typename _Tuple>
898 result_type
899 operator()(_CVRef& __arg, _Tuple&) const volatile
900 { return __arg.get(); }
901 };
902
903 /**
904 * If the argument is a bind expression, we invoke the underlying
905 * function object with the same cv-qualifiers as we are given and
906 * pass along all of our arguments (unwrapped). [TR1 3.6.3/5 bullet 2]
907 */
908 template<typename _Arg>
909 class _Mu<_Arg, true, false>
910 {
911 public:
912 template<typename _CVArg, typename... _Args>
913 auto
914 operator()(_CVArg& __arg,
915 tuple<_Args...>& __tuple) const volatile
916 -> decltype(__arg(declval<_Args>()...))
917 {
918 // Construct an index tuple and forward to __call
919 typedef typename _Build_index_tuple<sizeof...(_Args)>::__type
920 _Indexes;
921 return this->__call(__arg, __tuple, _Indexes());
922 }
923
924 private:
925 // Invokes the underlying function object __arg by unpacking all
926 // of the arguments in the tuple.
927 template<typename _CVArg, typename... _Args, std::size_t... _Indexes>
928 auto
929 __call(_CVArg& __arg, tuple<_Args...>& __tuple,
930 const _Index_tuple<_Indexes...>&) const volatile
931 -> decltype(__arg(declval<_Args>()...))
932 {
933 return __arg(std::forward<_Args>(std::get<_Indexes>(__tuple))...);
934 }
935 };
936
937 /**
938 * If the argument is a placeholder for the Nth argument, returns
939 * a reference to the Nth argument to the bind function object.
940 * [TR1 3.6.3/5 bullet 3]
941 */
942 template<typename _Arg>
943 class _Mu<_Arg, false, true>
944 {
945 public:
946 template<typename _Signature> class result;
947
948 template<typename _CVMu, typename _CVArg, typename _Tuple>
949 class result<_CVMu(_CVArg, _Tuple)>
950 {
951 // Add a reference, if it hasn't already been done for us.
952 // This allows us to be a little bit sloppy in constructing
953 // the tuple that we pass to result_of<...>.
954 typedef typename _Safe_tuple_element<(is_placeholder<_Arg>::value
955 - 1), _Tuple>::type
956 __base_type;
957
958 public:
959 typedef typename add_rvalue_reference<__base_type>::type type;
960 };
961
962 template<typename _Tuple>
963 typename result<_Mu(_Arg, _Tuple)>::type
964 operator()(const volatile _Arg&, _Tuple& __tuple) const volatile
965 {
966 return std::forward<typename result<_Mu(_Arg, _Tuple)>::type>(
967 ::std::get<(is_placeholder<_Arg>::value - 1)>(__tuple));
968 }
969 };
970
971 /**
972 * If the argument is just a value, returns a reference to that
973 * value. The cv-qualifiers on the reference are the same as the
974 * cv-qualifiers on the _Mu object. [TR1 3.6.3/5 bullet 4]
975 */
976 template<typename _Arg>
977 class _Mu<_Arg, false, false>
978 {
979 public:
980 template<typename _Signature> struct result;
981
982 template<typename _CVMu, typename _CVArg, typename _Tuple>
983 struct result<_CVMu(_CVArg, _Tuple)>
984 {
985 typedef typename add_lvalue_reference<_CVArg>::type type;
986 };
987
988 // Pick up the cv-qualifiers of the argument
989 template<typename _CVArg, typename _Tuple>
990 _CVArg&&
991 operator()(_CVArg&& __arg, _Tuple&) const volatile
992 { return std::forward<_CVArg>(__arg); }
993 };
994
995 /**
996 * Maps member pointers into instances of _Mem_fn but leaves all
997 * other function objects untouched. Used by std::bind(). The
998 * primary template handles the non-member-pointer case.
999 */
1000 template<typename _Tp>
1001 struct _Maybe_wrap_member_pointer
1002 {
1003 typedef _Tp type;
1004
1005 static const _Tp&
1006 __do_wrap(const _Tp& __x)
1007 { return __x; }
1008
1009 static _Tp&&
1010 __do_wrap(_Tp&& __x)
1011 { return static_cast<_Tp&&>(__x); }
1012 };
1013
1014 /**
1015 * Maps member pointers into instances of _Mem_fn but leaves all
1016 * other function objects untouched. Used by std::bind(). This
1017 * partial specialization handles the member pointer case.
1018 */
1019 template<typename _Tp, typename _Class>
1020 struct _Maybe_wrap_member_pointer<_Tp _Class::*>
1021 {
1022 typedef _Mem_fn<_Tp _Class::*> type;
1023
1024 static type
1025 __do_wrap(_Tp _Class::* __pm)
1026 { return type(__pm); }
1027 };
1028
1029 // Specialization needed to prevent "forming reference to void" errors when
1030 // bind<void>() is called, because argument deduction instantiates
1031 // _Maybe_wrap_member_pointer<void> outside the immediate context where
1032 // SFINAE applies.
1033 template<>
1034 struct _Maybe_wrap_member_pointer<void>
1035 {
1036 typedef void type;
1037 };
1038
1039 // std::get<I> for volatile-qualified tuples
1040 template<std::size_t _Ind, typename... _Tp>
1041 inline auto
1042 __volget(volatile tuple<_Tp...>& __tuple)
1043 -> __tuple_element_t<_Ind, tuple<_Tp...>> volatile&
1044 { return std::get<_Ind>(const_cast<tuple<_Tp...>&>(__tuple)); }
1045
1046 // std::get<I> for const-volatile-qualified tuples
1047 template<std::size_t _Ind, typename... _Tp>
1048 inline auto
1049 __volget(const volatile tuple<_Tp...>& __tuple)
1050 -> __tuple_element_t<_Ind, tuple<_Tp...>> const volatile&
1051 { return std::get<_Ind>(const_cast<const tuple<_Tp...>&>(__tuple)); }
1052
1053 /// Type of the function object returned from bind().
1054 template<typename _Signature>
1055 struct _Bind;
1056
1057 template<typename _Functor, typename... _Bound_args>
1058 class _Bind<_Functor(_Bound_args...)>
1059 : public _Weak_result_type<_Functor>
1060 {
1061 typedef _Bind __self_type;
1062 typedef typename _Build_index_tuple<sizeof...(_Bound_args)>::__type
1063 _Bound_indexes;
1064
1065 _Functor _M_f;
1066 tuple<_Bound_args...> _M_bound_args;
1067
1068 // Call unqualified
1069 template<typename _Result, typename... _Args, std::size_t... _Indexes>
1070 _Result
1071 __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
1072 {
1073 return _M_f(_Mu<_Bound_args>()
1074 (std::get<_Indexes>(_M_bound_args), __args)...);
1075 }
1076
1077 // Call as const
1078 template<typename _Result, typename... _Args, std::size_t... _Indexes>
1079 _Result
1080 __call_c(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
1081 {
1082 return _M_f(_Mu<_Bound_args>()
1083 (std::get<_Indexes>(_M_bound_args), __args)...);
1084 }
1085
1086 // Call as volatile
1087 template<typename _Result, typename... _Args, std::size_t... _Indexes>
1088 _Result
1089 __call_v(tuple<_Args...>&& __args,
1090 _Index_tuple<_Indexes...>) volatile
1091 {
1092 return _M_f(_Mu<_Bound_args>()
1093 (__volget<_Indexes>(_M_bound_args), __args)...);
1094 }
1095
1096 // Call as const volatile
1097 template<typename _Result, typename... _Args, std::size_t... _Indexes>
1098 _Result
1099 __call_c_v(tuple<_Args...>&& __args,
1100 _Index_tuple<_Indexes...>) const volatile
1101 {
1102 return _M_f(_Mu<_Bound_args>()
1103 (__volget<_Indexes>(_M_bound_args), __args)...);
1104 }
1105
1106 public:
1107 template<typename... _Args>
1108 explicit _Bind(const _Functor& __f, _Args&&... __args)
1109 : _M_f(__f), _M_bound_args(std::forward<_Args>(__args)...)
1110 { }
1111
1112 template<typename... _Args>
1113 explicit _Bind(_Functor&& __f, _Args&&... __args)
1114 : _M_f(std::move(__f)), _M_bound_args(std::forward<_Args>(__args)...)
1115 { }
1116
1117 _Bind(const _Bind&) = default;
1118
1119 _Bind(_Bind&& __b)
1120 : _M_f(std::move(__b._M_f)), _M_bound_args(std::move(__b._M_bound_args))
1121 { }
1122
1123 // Call unqualified
1124 template<typename... _Args, typename _Result
1125 = decltype( std::declval<_Functor&>()(
1126 _Mu<_Bound_args>()( std::declval<_Bound_args&>(),
1127 std::declval<tuple<_Args...>&>() )... ) )>
1128 _Result
1129 operator()(_Args&&... __args)
1130 {
1131 return this->__call<_Result>(
1132 std::forward_as_tuple(std::forward<_Args>(__args)...),
1133 _Bound_indexes());
1134 }
1135
1136 // Call as const
1137 template<typename... _Args, typename _Result
1138 = decltype( std::declval<typename enable_if<(sizeof...(_Args) >= 0),
1139 typename add_const<_Functor>::type&>::type>()(
1140 _Mu<_Bound_args>()( std::declval<const _Bound_args&>(),
1141 std::declval<tuple<_Args...>&>() )... ) )>
1142 _Result
1143 operator()(_Args&&... __args) const
1144 {
1145 return this->__call_c<_Result>(
1146 std::forward_as_tuple(std::forward<_Args>(__args)...),
1147 _Bound_indexes());
1148 }
1149
1150 // Call as volatile
1151 template<typename... _Args, typename _Result
1152 = decltype( std::declval<typename enable_if<(sizeof...(_Args) >= 0),
1153 typename add_volatile<_Functor>::type&>::type>()(
1154 _Mu<_Bound_args>()( std::declval<volatile _Bound_args&>(),
1155 std::declval<tuple<_Args...>&>() )... ) )>
1156 _Result
1157 operator()(_Args&&... __args) volatile
1158 {
1159 return this->__call_v<_Result>(
1160 std::forward_as_tuple(std::forward<_Args>(__args)...),
1161 _Bound_indexes());
1162 }
1163
1164 // Call as const volatile
1165 template<typename... _Args, typename _Result
1166 = decltype( std::declval<typename enable_if<(sizeof...(_Args) >= 0),
1167 typename add_cv<_Functor>::type&>::type>()(
1168 _Mu<_Bound_args>()( std::declval<const volatile _Bound_args&>(),
1169 std::declval<tuple<_Args...>&>() )... ) )>
1170 _Result
1171 operator()(_Args&&... __args) const volatile
1172 {
1173 return this->__call_c_v<_Result>(
1174 std::forward_as_tuple(std::forward<_Args>(__args)...),
1175 _Bound_indexes());
1176 }
1177 };
1178
1179 /// Type of the function object returned from bind<R>().
1180 template<typename _Result, typename _Signature>
1181 struct _Bind_result;
1182
1183 template<typename _Result, typename _Functor, typename... _Bound_args>
1184 class _Bind_result<_Result, _Functor(_Bound_args...)>
1185 {
1186 typedef _Bind_result __self_type;
1187 typedef typename _Build_index_tuple<sizeof...(_Bound_args)>::__type
1188 _Bound_indexes;
1189
1190 _Functor _M_f;
1191 tuple<_Bound_args...> _M_bound_args;
1192
1193 // sfinae types
1194 template<typename _Res>
1195 struct __enable_if_void : enable_if<is_void<_Res>::value, int> { };
1196 template<typename _Res>
1197 struct __disable_if_void : enable_if<!is_void<_Res>::value, int> { };
1198
1199 // Call unqualified
1200 template<typename _Res, typename... _Args, std::size_t... _Indexes>
1201 _Result
1202 __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
1203 typename __disable_if_void<_Res>::type = 0)
1204 {
1205 return _M_f(_Mu<_Bound_args>()
1206 (std::get<_Indexes>(_M_bound_args), __args)...);
1207 }
1208
1209 // Call unqualified, return void
1210 template<typename _Res, typename... _Args, std::size_t... _Indexes>
1211 void
1212 __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
1213 typename __enable_if_void<_Res>::type = 0)
1214 {
1215 _M_f(_Mu<_Bound_args>()
1216 (std::get<_Indexes>(_M_bound_args), __args)...);
1217 }
1218
1219 // Call as const
1220 template<typename _Res, typename... _Args, std::size_t... _Indexes>
1221 _Result
1222 __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
1223 typename __disable_if_void<_Res>::type = 0) const
1224 {
1225 return _M_f(_Mu<_Bound_args>()
1226 (std::get<_Indexes>(_M_bound_args), __args)...);
1227 }
1228
1229 // Call as const, return void
1230 template<typename _Res, typename... _Args, std::size_t... _Indexes>
1231 void
1232 __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
1233 typename __enable_if_void<_Res>::type = 0) const
1234 {
1235 _M_f(_Mu<_Bound_args>()
1236 (std::get<_Indexes>(_M_bound_args), __args)...);
1237 }
1238
1239 // Call as volatile
1240 template<typename _Res, typename... _Args, std::size_t... _Indexes>
1241 _Result
1242 __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
1243 typename __disable_if_void<_Res>::type = 0) volatile
1244 {
1245 return _M_f(_Mu<_Bound_args>()
1246 (__volget<_Indexes>(_M_bound_args), __args)...);
1247 }
1248
1249 // Call as volatile, return void
1250 template<typename _Res, typename... _Args, std::size_t... _Indexes>
1251 void
1252 __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
1253 typename __enable_if_void<_Res>::type = 0) volatile
1254 {
1255 _M_f(_Mu<_Bound_args>()
1256 (__volget<_Indexes>(_M_bound_args), __args)...);
1257 }
1258
1259 // Call as const volatile
1260 template<typename _Res, typename... _Args, std::size_t... _Indexes>
1261 _Result
1262 __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
1263 typename __disable_if_void<_Res>::type = 0) const volatile
1264 {
1265 return _M_f(_Mu<_Bound_args>()
1266 (__volget<_Indexes>(_M_bound_args), __args)...);
1267 }
1268
1269 // Call as const volatile, return void
1270 template<typename _Res, typename... _Args, std::size_t... _Indexes>
1271 void
1272 __call(tuple<_Args...>&& __args,
1273 _Index_tuple<_Indexes...>,
1274 typename __enable_if_void<_Res>::type = 0) const volatile
1275 {
1276 _M_f(_Mu<_Bound_args>()
1277 (__volget<_Indexes>(_M_bound_args), __args)...);
1278 }
1279
1280 public:
1281 typedef _Result result_type;
1282
1283 template<typename... _Args>
1284 explicit _Bind_result(const _Functor& __f, _Args&&... __args)
1285 : _M_f(__f), _M_bound_args(std::forward<_Args>(__args)...)
1286 { }
1287
1288 template<typename... _Args>
1289 explicit _Bind_result(_Functor&& __f, _Args&&... __args)
1290 : _M_f(std::move(__f)), _M_bound_args(std::forward<_Args>(__args)...)
1291 { }
1292
1293 _Bind_result(const _Bind_result&) = default;
1294
1295 _Bind_result(_Bind_result&& __b)
1296 : _M_f(std::move(__b._M_f)), _M_bound_args(std::move(__b._M_bound_args))
1297 { }
1298
1299 // Call unqualified
1300 template<typename... _Args>
1301 result_type
1302 operator()(_Args&&... __args)
1303 {
1304 return this->__call<_Result>(
1305 std::forward_as_tuple(std::forward<_Args>(__args)...),
1306 _Bound_indexes());
1307 }
1308
1309 // Call as const
1310 template<typename... _Args>
1311 result_type
1312 operator()(_Args&&... __args) const
1313 {
1314 return this->__call<_Result>(
1315 std::forward_as_tuple(std::forward<_Args>(__args)...),
1316 _Bound_indexes());
1317 }
1318
1319 // Call as volatile
1320 template<typename... _Args>
1321 result_type
1322 operator()(_Args&&... __args) volatile
1323 {
1324 return this->__call<_Result>(
1325 std::forward_as_tuple(std::forward<_Args>(__args)...),
1326 _Bound_indexes());
1327 }
1328
1329 // Call as const volatile
1330 template<typename... _Args>
1331 result_type
1332 operator()(_Args&&... __args) const volatile
1333 {
1334 return this->__call<_Result>(
1335 std::forward_as_tuple(std::forward<_Args>(__args)...),
1336 _Bound_indexes());
1337 }
1338 };
1339
1340 /**
1341 * @brief Class template _Bind is always a bind expression.
1342 * @ingroup binders
1343 */
1344 template<typename _Signature>
1345 struct is_bind_expression<_Bind<_Signature> >
1346 : public true_type { };
1347
1348 /**
1349 * @brief Class template _Bind is always a bind expression.
1350 * @ingroup binders
1351 */
1352 template<typename _Signature>
1353 struct is_bind_expression<const _Bind<_Signature> >
1354 : public true_type { };
1355
1356 /**
1357 * @brief Class template _Bind is always a bind expression.
1358 * @ingroup binders
1359 */
1360 template<typename _Signature>
1361 struct is_bind_expression<volatile _Bind<_Signature> >
1362 : public true_type { };
1363
1364 /**
1365 * @brief Class template _Bind is always a bind expression.
1366 * @ingroup binders
1367 */
1368 template<typename _Signature>
1369 struct is_bind_expression<const volatile _Bind<_Signature>>
1370 : public true_type { };
1371
1372 /**
1373 * @brief Class template _Bind_result is always a bind expression.
1374 * @ingroup binders
1375 */
1376 template<typename _Result, typename _Signature>
1377 struct is_bind_expression<_Bind_result<_Result, _Signature>>
1378 : public true_type { };
1379
1380 /**
1381 * @brief Class template _Bind_result is always a bind expression.
1382 * @ingroup binders
1383 */
1384 template<typename _Result, typename _Signature>
1385 struct is_bind_expression<const _Bind_result<_Result, _Signature>>
1386 : public true_type { };
1387
1388 /**
1389 * @brief Class template _Bind_result is always a bind expression.
1390 * @ingroup binders
1391 */
1392 template<typename _Result, typename _Signature>
1393 struct is_bind_expression<volatile _Bind_result<_Result, _Signature>>
1394 : public true_type { };
1395
1396 /**
1397 * @brief Class template _Bind_result is always a bind expression.
1398 * @ingroup binders
1399 */
1400 template<typename _Result, typename _Signature>
1401 struct is_bind_expression<const volatile _Bind_result<_Result, _Signature>>
1402 : public true_type { };
1403
1404 template<typename _Func, typename... _BoundArgs>
1405 struct _Bind_check_arity { };
1406
1407 template<typename _Ret, typename... _Args, typename... _BoundArgs>
1408 struct _Bind_check_arity<_Ret (*)(_Args...), _BoundArgs...>
1409 {
1410 static_assert(sizeof...(_BoundArgs) == sizeof...(_Args),
1411 "Wrong number of arguments for function");
1412 };
1413
1414 template<typename _Ret, typename... _Args, typename... _BoundArgs>
1415 struct _Bind_check_arity<_Ret (*)(_Args......), _BoundArgs...>
1416 {
1417 static_assert(sizeof...(_BoundArgs) >= sizeof...(_Args),
1418 "Wrong number of arguments for function");
1419 };
1420
1421 template<typename _Tp, typename _Class, typename... _BoundArgs>
1422 struct _Bind_check_arity<_Tp _Class::*, _BoundArgs...>
1423 {
1424 using _Arity = typename _Mem_fn<_Tp _Class::*>::_Arity;
1425 using _Varargs = typename _Mem_fn<_Tp _Class::*>::_Varargs;
1426 static_assert(_Varargs::value
1427 ? sizeof...(_BoundArgs) >= _Arity::value + 1
1428 : sizeof...(_BoundArgs) == _Arity::value + 1,
1429 "Wrong number of arguments for pointer-to-member");
1430 };
1431
1432 // Trait type used to remove std::bind() from overload set via SFINAE
1433 // when first argument has integer type, so that std::bind() will
1434 // not be a better match than ::bind() from the BSD Sockets API.
1435 template<typename _Tp, typename _Tp2 = typename decay<_Tp>::type>
1436 using __is_socketlike = __or_<is_integral<_Tp2>, is_enum<_Tp2>>;
1437
1438 template<bool _SocketLike, typename _Func, typename... _BoundArgs>
1439 struct _Bind_helper
1440 : _Bind_check_arity<typename decay<_Func>::type, _BoundArgs...>
1441 {
1442 typedef _Maybe_wrap_member_pointer<typename decay<_Func>::type>
1443 __maybe_type;
1444 typedef typename __maybe_type::type __func_type;
1445 typedef _Bind<__func_type(typename decay<_BoundArgs>::type...)> type;
1446 };
1447
1448 // Partial specialization for is_socketlike == true, does not define
1449 // nested type so std::bind() will not participate in overload resolution
1450 // when the first argument might be a socket file descriptor.
1451 template<typename _Func, typename... _BoundArgs>
1452 struct _Bind_helper<true, _Func, _BoundArgs...>
1453 { };
1454
1455 /**
1456 * @brief Function template for std::bind.
1457 * @ingroup binders
1458 */
1459 template<typename _Func, typename... _BoundArgs>
1460 inline typename
1461 _Bind_helper<__is_socketlike<_Func>::value, _Func, _BoundArgs...>::type
1462 bind(_Func&& __f, _BoundArgs&&... __args)
1463 {
1464 typedef _Bind_helper<false, _Func, _BoundArgs...> __helper_type;
1465 typedef typename __helper_type::__maybe_type __maybe_type;
1466 typedef typename __helper_type::type __result_type;
1467 return __result_type(__maybe_type::__do_wrap(std::forward<_Func>(__f)),
1468 std::forward<_BoundArgs>(__args)...);
1469 }
1470
1471 template<typename _Result, typename _Func, typename... _BoundArgs>
1472 struct _Bindres_helper
1473 : _Bind_check_arity<typename decay<_Func>::type, _BoundArgs...>
1474 {
1475 typedef _Maybe_wrap_member_pointer<typename decay<_Func>::type>
1476 __maybe_type;
1477 typedef typename __maybe_type::type __functor_type;
1478 typedef _Bind_result<_Result,
1479 __functor_type(typename decay<_BoundArgs>::type...)>
1480 type;
1481 };
1482
1483 /**
1484 * @brief Function template for std::bind<R>.
1485 * @ingroup binders
1486 */
1487 template<typename _Result, typename _Func, typename... _BoundArgs>
1488 inline
1489 typename _Bindres_helper<_Result, _Func, _BoundArgs...>::type
1490 bind(_Func&& __f, _BoundArgs&&... __args)
1491 {
1492 typedef _Bindres_helper<_Result, _Func, _BoundArgs...> __helper_type;
1493 typedef typename __helper_type::__maybe_type __maybe_type;
1494 typedef typename __helper_type::type __result_type;
1495 return __result_type(__maybe_type::__do_wrap(std::forward<_Func>(__f)),
1496 std::forward<_BoundArgs>(__args)...);
1497 }
1498
1499 template<typename _Signature>
1500 struct _Bind_simple;
1501
1502 template<typename _Callable, typename... _Args>
1503 struct _Bind_simple<_Callable(_Args...)>
1504 {
1505 typedef typename result_of<_Callable(_Args...)>::type result_type;
1506
1507 template<typename _Tp, typename... _Up>
1508 explicit
1509 _Bind_simple(_Tp&& __f, _Up&&... __args)
1510 : _M_bound(std::forward<_Tp>(__f), std::forward<_Up>(__args)...)
1511 { }
1512
1513 _Bind_simple(const _Bind_simple&) = default;
1514 _Bind_simple(_Bind_simple&&) = default;
1515
1516 result_type
1517 operator()()
1518 {
1519 typedef typename _Build_index_tuple<sizeof...(_Args)>::__type _Indices;
1520 return _M_invoke(_Indices());
1521 }
1522
1523 private:
1524 template<std::size_t... _Indices>
1525 typename result_of<_Callable(_Args...)>::type
1526 _M_invoke(_Index_tuple<_Indices...>)
1527 {
1528 // std::bind always forwards bound arguments as lvalues,
1529 // but this type can call functions which only accept rvalues.
1530 return std::forward<_Callable>(std::get<0>(_M_bound))(
1531 std::forward<_Args>(std::get<_Indices+1>(_M_bound))...);
1532 }
1533
1534 std::tuple<_Callable, _Args...> _M_bound;
1535 };
1536
1537 template<typename _Func, typename... _BoundArgs>
1538 struct _Bind_simple_helper
1539 : _Bind_check_arity<typename decay<_Func>::type, _BoundArgs...>
1540 {
1541 typedef _Maybe_wrap_member_pointer<typename decay<_Func>::type>
1542 __maybe_type;
1543 typedef typename __maybe_type::type __func_type;
1544 typedef _Bind_simple<__func_type(typename decay<_BoundArgs>::type...)>
1545 __type;
1546 };
1547
1548 // Simplified version of std::bind for internal use, without support for
1549 // unbound arguments, placeholders or nested bind expressions.
1550 template<typename _Callable, typename... _Args>
1551 typename _Bind_simple_helper<_Callable, _Args...>::__type
1552 __bind_simple(_Callable&& __callable, _Args&&... __args)
1553 {
1554 typedef _Bind_simple_helper<_Callable, _Args...> __helper_type;
1555 typedef typename __helper_type::__maybe_type __maybe_type;
1556 typedef typename __helper_type::__type __result_type;
1557 return __result_type(
1558 __maybe_type::__do_wrap( std::forward<_Callable>(__callable)),
1559 std::forward<_Args>(__args)...);
1560 }
1561
1562 /**
1563 * @brief Exception class thrown when class template function's
1564 * operator() is called with an empty target.
1565 * @ingroup exceptions
1566 */
1567 class bad_function_call : public std::exception
1568 {
1569 public:
1570 virtual ~bad_function_call() noexcept;
1571
1572 const char* what() const noexcept;
1573 };
1574
1575 /**
1576 * Trait identifying "location-invariant" types, meaning that the
1577 * address of the object (or any of its members) will not escape.
1578 * Trivially copyable types are location-invariant and users can
1579 * specialize this trait for other types.
1580 */
1581 template<typename _Tp>
1582 struct __is_location_invariant
1583 : is_trivially_copyable<_Tp>::type
1584 { };
1585
1586 class _Undefined_class;
1587
1588 union _Nocopy_types
1589 {
1590 void* _M_object;
1591 const void* _M_const_object;
1592 void (*_M_function_pointer)();
1593 void (_Undefined_class::*_M_member_pointer)();
1594 };
1595
1596 union _Any_data
1597 {
1598 void* _M_access() { return &_M_pod_data[0]; }
1599 const void* _M_access() const { return &_M_pod_data[0]; }
1600
1601 template<typename _Tp>
1602 _Tp&
1603 _M_access()
1604 { return *static_cast<_Tp*>(_M_access()); }
1605
1606 template<typename _Tp>
1607 const _Tp&
1608 _M_access() const
1609 { return *static_cast<const _Tp*>(_M_access()); }
1610
1611 _Nocopy_types _M_unused;
1612 char _M_pod_data[sizeof(_Nocopy_types)];
1613 };
1614
1615 enum _Manager_operation
1616 {
1617 __get_type_info,
1618 __get_functor_ptr,
1619 __clone_functor,
1620 __destroy_functor
1621 };
1622
1623 // Simple type wrapper that helps avoid annoying const problems
1624 // when casting between void pointers and pointers-to-pointers.
1625 template<typename _Tp>
1626 struct _Simple_type_wrapper
1627 {
1628 _Simple_type_wrapper(_Tp __value) : __value(__value) { }
1629
1630 _Tp __value;
1631 };
1632
1633 template<typename _Tp>
1634 struct __is_location_invariant<_Simple_type_wrapper<_Tp> >
1635 : __is_location_invariant<_Tp>
1636 { };
1637
1638 // Converts a reference to a function object into a callable
1639 // function object.
1640 template<typename _Functor>
1641 inline _Functor&
1642 __callable_functor(_Functor& __f)
1643 { return __f; }
1644
1645 template<typename _Member, typename _Class>
1646 inline _Mem_fn<_Member _Class::*>
1647 __callable_functor(_Member _Class::* &__p)
1648 { return std::mem_fn(__p); }
1649
1650 template<typename _Member, typename _Class>
1651 inline _Mem_fn<_Member _Class::*>
1652 __callable_functor(_Member _Class::* const &__p)
1653 { return std::mem_fn(__p); }
1654
1655 template<typename _Member, typename _Class>
1656 inline _Mem_fn<_Member _Class::*>
1657 __callable_functor(_Member _Class::* volatile &__p)
1658 { return std::mem_fn(__p); }
1659
1660 template<typename _Member, typename _Class>
1661 inline _Mem_fn<_Member _Class::*>
1662 __callable_functor(_Member _Class::* const volatile &__p)
1663 { return std::mem_fn(__p); }
1664
1665 template<typename _Signature>
1666 class function;
1667
1668 /// Base class of all polymorphic function object wrappers.
1669 class _Function_base
1670 {
1671 public:
1672 static const std::size_t _M_max_size = sizeof(_Nocopy_types);
1673 static const std::size_t _M_max_align = __alignof__(_Nocopy_types);
1674
1675 template<typename _Functor>
1676 class _Base_manager
1677 {
1678 protected:
1679 static const bool __stored_locally =
1680 (__is_location_invariant<_Functor>::value
1681 && sizeof(_Functor) <= _M_max_size
1682 && __alignof__(_Functor) <= _M_max_align
1683 && (_M_max_align % __alignof__(_Functor) == 0));
1684
1685 typedef integral_constant<bool, __stored_locally> _Local_storage;
1686
1687 // Retrieve a pointer to the function object
1688 static _Functor*
1689 _M_get_pointer(const _Any_data& __source)
1690 {
1691 const _Functor* __ptr =
1692 __stored_locally? std::__addressof(__source._M_access<_Functor>())
1693 /* have stored a pointer */ : __source._M_access<_Functor*>();
1694 return const_cast<_Functor*>(__ptr);
1695 }
1696
1697 // Clone a location-invariant function object that fits within
1698 // an _Any_data structure.
1699 static void
1700 _M_clone(_Any_data& __dest, const _Any_data& __source, true_type)
1701 {
1702 new (__dest._M_access()) _Functor(__source._M_access<_Functor>());
1703 }
1704
1705 // Clone a function object that is not location-invariant or
1706 // that cannot fit into an _Any_data structure.
1707 static void
1708 _M_clone(_Any_data& __dest, const _Any_data& __source, false_type)
1709 {
1710 __dest._M_access<_Functor*>() =
1711 new _Functor(*__source._M_access<_Functor*>());
1712 }
1713
1714 // Destroying a location-invariant object may still require
1715 // destruction.
1716 static void
1717 _M_destroy(_Any_data& __victim, true_type)
1718 {
1719 __victim._M_access<_Functor>().~_Functor();
1720 }
1721
1722 // Destroying an object located on the heap.
1723 static void
1724 _M_destroy(_Any_data& __victim, false_type)
1725 {
1726 delete __victim._M_access<_Functor*>();
1727 }
1728
1729 public:
1730 static bool
1731 _M_manager(_Any_data& __dest, const _Any_data& __source,
1732 _Manager_operation __op)
1733 {
1734 switch (__op)
1735 {
1736#if __cpp_rtti
1737 case __get_type_info:
1738 __dest._M_access<const type_info*>() = &typeid(_Functor);
1739 break;
1740#endif
1741 case __get_functor_ptr:
1742 __dest._M_access<_Functor*>() = _M_get_pointer(__source);
1743 break;
1744
1745 case __clone_functor:
1746 _M_clone(__dest, __source, _Local_storage());
1747 break;
1748
1749 case __destroy_functor:
1750 _M_destroy(__dest, _Local_storage());
1751 break;
1752 }
1753 return false;
1754 }
1755
1756 static void
1757 _M_init_functor(_Any_data& __functor, _Functor&& __f)
1758 { _M_init_functor(__functor, std::move(__f), _Local_storage()); }
1759
1760 template<typename _Signature>
1761 static bool
1762 _M_not_empty_function(const function<_Signature>& __f)
1763 { return static_cast<bool>(__f); }
1764
1765 template<typename _Tp>
1766 static bool
1767 _M_not_empty_function(_Tp* const& __fp)
1768 { return __fp; }
1769
1770 template<typename _Class, typename _Tp>
1771 static bool
1772 _M_not_empty_function(_Tp _Class::* const& __mp)
1773 { return __mp; }
1774
1775 template<typename _Tp>
1776 static bool
1777 _M_not_empty_function(const _Tp&)
1778 { return true; }
1779
1780 private:
1781 static void
1782 _M_init_functor(_Any_data& __functor, _Functor&& __f, true_type)
1783 { new (__functor._M_access()) _Functor(std::move(__f)); }
1784
1785 static void
1786 _M_init_functor(_Any_data& __functor, _Functor&& __f, false_type)
1787 { __functor._M_access<_Functor*>() = new _Functor(std::move(__f)); }
1788 };
1789
1790 template<typename _Functor>
1791 class _Ref_manager : public _Base_manager<_Functor*>
1792 {
1793 typedef _Function_base::_Base_manager<_Functor*> _Base;
1794
1795 public:
1796 static bool
1797 _M_manager(_Any_data& __dest, const _Any_data& __source,
1798 _Manager_operation __op)
1799 {
1800 switch (__op)
1801 {
1802#if __cpp_rtti
1803 case __get_type_info:
1804 __dest._M_access<const type_info*>() = &typeid(_Functor);
1805 break;
1806#endif
1807 case __get_functor_ptr:
1808 __dest._M_access<_Functor*>() = *_Base::_M_get_pointer(__source);
1809 return is_const<_Functor>::value;
1810 break;
1811
1812 default:
1813 _Base::_M_manager(__dest, __source, __op);
1814 }
1815 return false;
1816 }
1817
1818 static void
1819 _M_init_functor(_Any_data& __functor, reference_wrapper<_Functor> __f)
1820 {
1821 _Base::_M_init_functor(__functor, std::__addressof(__f.get()));
1822 }
1823 };
1824
1825 _Function_base() : _M_manager(nullptr) { }
1826
1827 ~_Function_base()
1828 {
1829 if (_M_manager)
1830 _M_manager(_M_functor, _M_functor, __destroy_functor);
1831 }
1832
1833
1834 bool _M_empty() const { return !_M_manager; }
1835
1836 typedef bool (*_Manager_type)(_Any_data&, const _Any_data&,
1837 _Manager_operation);
1838
1839 _Any_data _M_functor;
1840 _Manager_type _M_manager;
1841 };
1842
1843 template<typename _Signature, typename _Functor>
1844 class _Function_handler;
1845
1846 template<typename _Res, typename _Functor, typename... _ArgTypes>
1847 class _Function_handler<_Res(_ArgTypes...), _Functor>
1848 : public _Function_base::_Base_manager<_Functor>
1849 {
1850 typedef _Function_base::_Base_manager<_Functor> _Base;
1851
1852 public:
1853 static _Res
1854 _M_invoke(const _Any_data& __functor, _ArgTypes&&... __args)
1855 {
1856 return (*_Base::_M_get_pointer(__functor))(
1857 std::forward<_ArgTypes>(__args)...);
1858 }
1859 };
1860
1861 template<typename _Functor, typename... _ArgTypes>
1862 class _Function_handler<void(_ArgTypes...), _Functor>
1863 : public _Function_base::_Base_manager<_Functor>
1864 {
1865 typedef _Function_base::_Base_manager<_Functor> _Base;
1866
1867 public:
1868 static void
1869 _M_invoke(const _Any_data& __functor, _ArgTypes&&... __args)
1870 {
1871 (*_Base::_M_get_pointer(__functor))(
1872 std::forward<_ArgTypes>(__args)...);
1873 }
1874 };
1875
1876 template<typename _Res, typename _Functor, typename... _ArgTypes>
1877 class _Function_handler<_Res(_ArgTypes...), reference_wrapper<_Functor> >
1878 : public _Function_base::_Ref_manager<_Functor>
1879 {
1880 typedef _Function_base::_Ref_manager<_Functor> _Base;
1881
1882 public:
1883 static _Res
1884 _M_invoke(const _Any_data& __functor, _ArgTypes&&... __args)
1885 {
1886 return std::__callable_functor(**_Base::_M_get_pointer(__functor))(
1887 std::forward<_ArgTypes>(__args)...);
1888 }
1889 };
1890
1891 template<typename _Functor, typename... _ArgTypes>
1892 class _Function_handler<void(_ArgTypes...), reference_wrapper<_Functor> >
1893 : public _Function_base::_Ref_manager<_Functor>
1894 {
1895 typedef _Function_base::_Ref_manager<_Functor> _Base;
1896
1897 public:
1898 static void
1899 _M_invoke(const _Any_data& __functor, _ArgTypes&&... __args)
1900 {
1901 std::__callable_functor(**_Base::_M_get_pointer(__functor))(
1902 std::forward<_ArgTypes>(__args)...);
1903 }
1904 };
1905
1906 template<typename _Class, typename _Member, typename _Res,
1907 typename... _ArgTypes>
1908 class _Function_handler<_Res(_ArgTypes...), _Member _Class::*>
1909 : public _Function_handler<void(_ArgTypes...), _Member _Class::*>
1910 {
1911 typedef _Function_handler<void(_ArgTypes...), _Member _Class::*>
1912 _Base;
1913
1914 public:
1915 static _Res
1916 _M_invoke(const _Any_data& __functor, _ArgTypes&&... __args)
1917 {
1918 return std::mem_fn(_Base::_M_get_pointer(__functor)->__value)(
1919 std::forward<_ArgTypes>(__args)...);
1920 }
1921 };
1922
1923 template<typename _Class, typename _Member, typename... _ArgTypes>
1924 class _Function_handler<void(_ArgTypes...), _Member _Class::*>
1925 : public _Function_base::_Base_manager<
1926 _Simple_type_wrapper< _Member _Class::* > >
1927 {
1928 typedef _Member _Class::* _Functor;
1929 typedef _Simple_type_wrapper<_Functor> _Wrapper;
1930 typedef _Function_base::_Base_manager<_Wrapper> _Base;
1931
1932 public:
1933 static bool
1934 _M_manager(_Any_data& __dest, const _Any_data& __source,
1935 _Manager_operation __op)
1936 {
1937 switch (__op)
1938 {
1939#if __cpp_rtti
1940 case __get_type_info:
1941 __dest._M_access<const type_info*>() = &typeid(_Functor);
1942 break;
1943#endif
1944 case __get_functor_ptr:
1945 __dest._M_access<_Functor*>() =
1946 &_Base::_M_get_pointer(__source)->__value;
1947 break;
1948
1949 default:
1950 _Base::_M_manager(__dest, __source, __op);
1951 }
1952 return false;
1953 }
1954
1955 static void
1956 _M_invoke(const _Any_data& __functor, _ArgTypes&&... __args)
1957 {
1958 std::mem_fn(_Base::_M_get_pointer(__functor)->__value)(
1959 std::forward<_ArgTypes>(__args)...);
1960 }
1961 };
1962
1963 template<typename _From, typename _To>
1964 using __check_func_return_type
1965 = __or_<is_void<_To>, is_convertible<_From, _To>>;
1966
1967 /**
1968 * @brief Primary class template for std::function.
1969 * @ingroup functors
1970 *
1971 * Polymorphic function wrapper.
1972 */
1973 template<typename _Res, typename... _ArgTypes>
1974 class function<_Res(_ArgTypes...)>
1975 : public _Maybe_unary_or_binary_function<_Res, _ArgTypes...>,
1976 private _Function_base
1977 {
1978 typedef _Res _Signature_type(_ArgTypes...);
1979
1980 template<typename _Func,
1981 typename _Res2 = typename result_of<_Func(_ArgTypes...)>::type>
1982 struct _Callable : __check_func_return_type<_Res2, _Res> { };
1983
1984 // Used so the return type convertibility checks aren't done when
1985 // performing overload resolution for copy construction/assignment.
1986 template<typename _Tp>
1987 struct _Callable<function, _Tp> : false_type { };
1988
1989 template<typename _Cond, typename _Tp>
1990 using _Requires = typename enable_if<_Cond::value, _Tp>::type;
1991
1992 public:
1993 typedef _Res result_type;
1994
1995 // [3.7.2.1] construct/copy/destroy
1996
1997 /**
1998 * @brief Default construct creates an empty function call wrapper.
1999 * @post @c !(bool)*this
2000 */
2001 function() noexcept
2002 : _Function_base() { }
2003
2004 /**
2005 * @brief Creates an empty function call wrapper.
2006 * @post @c !(bool)*this
2007 */
2008 function(nullptr_t) noexcept
2009 : _Function_base() { }
2010
2011 /**
2012 * @brief %Function copy constructor.
2013 * @param __x A %function object with identical call signature.
2014 * @post @c bool(*this) == bool(__x)
2015 *
2016 * The newly-created %function contains a copy of the target of @a
2017 * __x (if it has one).
2018 */
2019 function(const function& __x);
2020
2021 /**
2022 * @brief %Function move constructor.
2023 * @param __x A %function object rvalue with identical call signature.
2024 *
2025 * The newly-created %function contains the target of @a __x
2026 * (if it has one).
2027 */
2028 function(function&& __x) : _Function_base()
2029 {
2030 __x.swap(*this);
2031 }
2032
2033 // TODO: needs allocator_arg_t
2034
2035 /**
2036 * @brief Builds a %function that targets a copy of the incoming
2037 * function object.
2038 * @param __f A %function object that is callable with parameters of
2039 * type @c T1, @c T2, ..., @c TN and returns a value convertible
2040 * to @c Res.
2041 *
2042 * The newly-created %function object will target a copy of
2043 * @a __f. If @a __f is @c reference_wrapper<F>, then this function
2044 * object will contain a reference to the function object @c
2045 * __f.get(). If @a __f is a NULL function pointer or NULL
2046 * pointer-to-member, the newly-created object will be empty.
2047 *
2048 * If @a __f is a non-NULL function pointer or an object of type @c
2049 * reference_wrapper<F>, this function will not throw.
2050 */
2051 template<typename _Functor,
2052 typename = _Requires<__not_<is_same<_Functor, function>>, void>,
2053 typename = _Requires<_Callable<_Functor>, void>>
2054 function(_Functor);
2055
2056 /**
2057 * @brief %Function assignment operator.
2058 * @param __x A %function with identical call signature.
2059 * @post @c (bool)*this == (bool)x
2060 * @returns @c *this
2061 *
2062 * The target of @a __x is copied to @c *this. If @a __x has no
2063 * target, then @c *this will be empty.
2064 *
2065 * If @a __x targets a function pointer or a reference to a function
2066 * object, then this operation will not throw an %exception.
2067 */
2068 function&
2069 operator=(const function& __x)
2070 {
2071 function(__x).swap(*this);
2072 return *this;
2073 }
2074
2075 /**
2076 * @brief %Function move-assignment operator.
2077 * @param __x A %function rvalue with identical call signature.
2078 * @returns @c *this
2079 *
2080 * The target of @a __x is moved to @c *this. If @a __x has no
2081 * target, then @c *this will be empty.
2082 *
2083 * If @a __x targets a function pointer or a reference to a function
2084 * object, then this operation will not throw an %exception.
2085 */
2086 function&
2087 operator=(function&& __x)
2088 {
2089 function(std::move(__x)).swap(*this);
2090 return *this;
2091 }
2092
2093 /**
2094 * @brief %Function assignment to zero.
2095 * @post @c !(bool)*this
2096 * @returns @c *this
2097 *
2098 * The target of @c *this is deallocated, leaving it empty.
2099 */
2100 function&
2101 operator=(nullptr_t) noexcept
2102 {
2103 if (_M_manager)
2104 {
2105 _M_manager(_M_functor, _M_functor, __destroy_functor);
2106 _M_manager = nullptr;
2107 _M_invoker = nullptr;
2108 }
2109 return *this;
2110 }
2111
2112 /**
2113 * @brief %Function assignment to a new target.
2114 * @param __f A %function object that is callable with parameters of
2115 * type @c T1, @c T2, ..., @c TN and returns a value convertible
2116 * to @c Res.
2117 * @return @c *this
2118 *
2119 * This %function object wrapper will target a copy of @a
2120 * __f. If @a __f is @c reference_wrapper<F>, then this function
2121 * object will contain a reference to the function object @c
2122 * __f.get(). If @a __f is a NULL function pointer or NULL
2123 * pointer-to-member, @c this object will be empty.
2124 *
2125 * If @a __f is a non-NULL function pointer or an object of type @c
2126 * reference_wrapper<F>, this function will not throw.
2127 */
2128 template<typename _Functor>
2129 _Requires<_Callable<typename decay<_Functor>::type>, function&>
2130 operator=(_Functor&& __f)
2131 {
2132 function(std::forward<_Functor>(__f)).swap(*this);
2133 return *this;
2134 }
2135
2136 /// @overload
2137 template<typename _Functor>
2138 function&
2139 operator=(reference_wrapper<_Functor> __f) noexcept
2140 {
2141 function(__f).swap(*this);
2142 return *this;
2143 }
2144
2145 // [3.7.2.2] function modifiers
2146
2147 /**
2148 * @brief Swap the targets of two %function objects.
2149 * @param __x A %function with identical call signature.
2150 *
2151 * Swap the targets of @c this function object and @a __f. This
2152 * function will not throw an %exception.
2153 */
2154 void swap(function& __x)
2155 {
2156 std::swap(_M_functor, __x._M_functor);
2157 std::swap(_M_manager, __x._M_manager);
2158 std::swap(_M_invoker, __x._M_invoker);
2159 }
2160
2161 // TODO: needs allocator_arg_t
2162 /*
2163 template<typename _Functor, typename _Alloc>
2164 void
2165 assign(_Functor&& __f, const _Alloc& __a)
2166 {
2167 function(allocator_arg, __a,
2168 std::forward<_Functor>(__f)).swap(*this);
2169 }
2170 */
2171
2172 // [3.7.2.3] function capacity
2173
2174 /**
2175 * @brief Determine if the %function wrapper has a target.
2176 *
2177 * @return @c true when this %function object contains a target,
2178 * or @c false when it is empty.
2179 *
2180 * This function will not throw an %exception.
2181 */
2182 explicit operator bool() const noexcept
2183 { return !_M_empty(); }
2184
2185 // [3.7.2.4] function invocation
2186
2187 /**
2188 * @brief Invokes the function targeted by @c *this.
2189 * @returns the result of the target.
2190 * @throws bad_function_call when @c !(bool)*this
2191 *
2192 * The function call operator invokes the target function object
2193 * stored by @c this.
2194 */
2195 _Res operator()(_ArgTypes... __args) const;
2196
2197#if __cpp_rtti
2198 // [3.7.2.5] function target access
2199 /**
2200 * @brief Determine the type of the target of this function object
2201 * wrapper.
2202 *
2203 * @returns the type identifier of the target function object, or
2204 * @c typeid(void) if @c !(bool)*this.
2205 *
2206 * This function will not throw an %exception.
2207 */
2208 const type_info& target_type() const noexcept;
2209
2210 /**
2211 * @brief Access the stored target function object.
2212 *
2213 * @return Returns a pointer to the stored target function object,
2214 * if @c typeid(Functor).equals(target_type()); otherwise, a NULL
2215 * pointer.
2216 *
2217 * This function will not throw an %exception.
2218 */
2219 template<typename _Functor> _Functor* target() noexcept;
2220
2221 /// @overload
2222 template<typename _Functor> const _Functor* target() const noexcept;
2223#endif
2224
2225 private:
2226 using _Invoker_type = _Res (*)(const _Any_data&, _ArgTypes&&...);
2227 _Invoker_type _M_invoker;
2228 };
2229
2230 // Out-of-line member definitions.
2231 template<typename _Res, typename... _ArgTypes>
2232 function<_Res(_ArgTypes...)>::
2233 function(const function& __x)
2234 : _Function_base()
2235 {
2236 if (static_cast<bool>(__x))
2237 {
2238 __x._M_manager(_M_functor, __x._M_functor, __clone_functor);
2239 _M_invoker = __x._M_invoker;
2240 _M_manager = __x._M_manager;
2241 }
2242 }
2243
2244 template<typename _Res, typename... _ArgTypes>
2245 template<typename _Functor, typename, typename>
2246 function<_Res(_ArgTypes...)>::
2247 function(_Functor __f)
2248 : _Function_base()
2249 {
2250 typedef _Function_handler<_Signature_type, _Functor> _My_handler;
2251
2252 if (_My_handler::_M_not_empty_function(__f))
2253 {
2254 _My_handler::_M_init_functor(_M_functor, std::move(__f));
2255 _M_invoker = &_My_handler::_M_invoke;
2256 _M_manager = &_My_handler::_M_manager;
2257 }
2258 }
2259
2260 template<typename _Res, typename... _ArgTypes>
2261 _Res
2262 function<_Res(_ArgTypes...)>::
2263 operator()(_ArgTypes... __args) const
2264 {
2265 if (_M_empty())
2266 __throw_bad_function_call();
2267 return _M_invoker(_M_functor, std::forward<_ArgTypes>(__args)...);
2268 }
2269
2270#if __cpp_rtti
2271 template<typename _Res, typename... _ArgTypes>
2272 const type_info&
2273 function<_Res(_ArgTypes...)>::
2274 target_type() const noexcept
2275 {
2276 if (_M_manager)
2277 {
2278 _Any_data __typeinfo_result;
2279 _M_manager(__typeinfo_result, _M_functor, __get_type_info);
2280 return *__typeinfo_result._M_access<const type_info*>();
2281 }
2282 else
2283 return typeid(void);
2284 }
2285
2286 template<typename _Res, typename... _ArgTypes>
2287 template<typename _Functor>
2288 _Functor*
2289 function<_Res(_ArgTypes...)>::
2290 target() noexcept
2291 {
2292 if (typeid(_Functor) == target_type() && _M_manager)
2293 {
2294 _Any_data __ptr;
2295 if (_M_manager(__ptr, _M_functor, __get_functor_ptr)
2296 && !is_const<_Functor>::value)
2297 return 0;
2298 else
2299 return __ptr._M_access<_Functor*>();
2300 }
2301 else
2302 return 0;
2303 }
2304
2305 template<typename _Res, typename... _ArgTypes>
2306 template<typename _Functor>
2307 const _Functor*
2308 function<_Res(_ArgTypes...)>::
2309 target() const noexcept
2310 {
2311 if (typeid(_Functor) == target_type() && _M_manager)
2312 {
2313 _Any_data __ptr;
2314 _M_manager(__ptr, _M_functor, __get_functor_ptr);
2315 return __ptr._M_access<const _Functor*>();
2316 }
2317 else
2318 return 0;
2319 }
2320#endif
2321
2322 // [20.7.15.2.6] null pointer comparisons
2323
2324 /**
2325 * @brief Compares a polymorphic function object wrapper against 0
2326 * (the NULL pointer).
2327 * @returns @c true if the wrapper has no target, @c false otherwise
2328 *
2329 * This function will not throw an %exception.
2330 */
2331 template<typename _Res, typename... _Args>
2332 inline bool
2333 operator==(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
2334 { return !static_cast<bool>(__f); }
2335
2336 /// @overload
2337 template<typename _Res, typename... _Args>
2338 inline bool
2339 operator==(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
2340 { return !static_cast<bool>(__f); }
2341
2342 /**
2343 * @brief Compares a polymorphic function object wrapper against 0
2344 * (the NULL pointer).
2345 * @returns @c false if the wrapper has no target, @c true otherwise
2346 *
2347 * This function will not throw an %exception.
2348 */
2349 template<typename _Res, typename... _Args>
2350 inline bool
2351 operator!=(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
2352 { return static_cast<bool>(__f); }
2353
2354 /// @overload
2355 template<typename _Res, typename... _Args>
2356 inline bool
2357 operator!=(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
2358 { return static_cast<bool>(__f); }
2359
2360 // [20.7.15.2.7] specialized algorithms
2361
2362 /**
2363 * @brief Swap the targets of two polymorphic function object wrappers.
2364 *
2365 * This function will not throw an %exception.
2366 */
2367 template<typename _Res, typename... _Args>
2368 inline void
2369 swap(function<_Res(_Args...)>& __x, function<_Res(_Args...)>& __y)
2370 { __x.swap(__y); }
2371
2372_GLIBCXX_END_NAMESPACE_VERSION
2373} // namespace std
2374
2375#endif // C++11
2376
2377#endif // _GLIBCXX_FUNCTIONAL
2378