xref: /freebsd/contrib/llvm-project/libcxx/include/functional (revision 43a5ec4eb41567cc92586503212743d89686d78f)
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
11#define _LIBCPP_FUNCTIONAL
12
13/*
14    functional synopsis
15
16namespace std
17{
18
19template <class Arg, class Result>
20struct unary_function
21{
22    typedef Arg    argument_type;
23    typedef Result result_type;
24};
25
26template <class Arg1, class Arg2, class Result>
27struct binary_function
28{
29    typedef Arg1   first_argument_type;
30    typedef Arg2   second_argument_type;
31    typedef Result result_type;
32};
33
34template <class T>
35class reference_wrapper
36    : public unary_function<T1, R> // if wrapping a unary functor
37    : public binary_function<T1, T2, R> // if wraping a binary functor
38{
39public:
40    // types
41    typedef T type;
42    typedef see below result_type; // Not always defined
43
44    // construct/copy/destroy
45    template<class U>
46      reference_wrapper(U&&);
47    reference_wrapper(const reference_wrapper<T>& x) noexcept;
48
49    // assignment
50    reference_wrapper& operator=(const reference_wrapper<T>& x) noexcept;
51
52    // access
53    operator T& () const noexcept;
54    T& get() const noexcept;
55
56    // invoke
57    template <class... ArgTypes>
58      typename result_of<T&(ArgTypes&&...)>::type
59          operator() (ArgTypes&&...) const;
60};
61
62template <class T>
63  reference_wrapper(T&) -> reference_wrapper<T>;
64
65template <class T> reference_wrapper<T> ref(T& t) noexcept;
66template <class T> void ref(const T&& t) = delete;
67template <class T> reference_wrapper<T> ref(reference_wrapper<T>t) noexcept;
68
69template <class T> reference_wrapper<const T> cref(const T& t) noexcept;
70template <class T> void cref(const T&& t) = delete;
71template <class T> reference_wrapper<const T> cref(reference_wrapper<T> t) noexcept;
72
73template <class T> struct unwrap_reference;                                       // since C++20
74template <class T> struct unwrap_ref_decay : unwrap_reference<decay_t<T>> { };    // since C++20
75template <class T> using unwrap_reference_t = typename unwrap_reference<T>::type; // since C++20
76template <class T> using unwrap_ref_decay_t = typename unwrap_ref_decay<T>::type; // since C++20
77
78template <class T> // <class T=void> in C++14
79struct plus {
80    T operator()(const T& x, const T& y) const;
81};
82
83template <class T> // <class T=void> in C++14
84struct minus {
85    T operator()(const T& x, const T& y) const;
86};
87
88template <class T> // <class T=void> in C++14
89struct multiplies {
90    T operator()(const T& x, const T& y) const;
91};
92
93template <class T> // <class T=void> in C++14
94struct divides {
95    T operator()(const T& x, const T& y) const;
96};
97
98template <class T> // <class T=void> in C++14
99struct modulus {
100    T operator()(const T& x, const T& y) const;
101};
102
103template <class T> // <class T=void> in C++14
104struct negate {
105    T operator()(const T& x) const;
106};
107
108template <class T> // <class T=void> in C++14
109struct equal_to {
110    bool operator()(const T& x, const T& y) const;
111};
112
113template <class T> // <class T=void> in C++14
114struct not_equal_to {
115    bool operator()(const T& x, const T& y) const;
116};
117
118template <class T> // <class T=void> in C++14
119struct greater {
120    bool operator()(const T& x, const T& y) const;
121};
122
123template <class T> // <class T=void> in C++14
124struct less {
125    bool operator()(const T& x, const T& y) const;
126};
127
128template <class T> // <class T=void> in C++14
129struct greater_equal {
130    bool operator()(const T& x, const T& y) const;
131};
132
133template <class T> // <class T=void> in C++14
134struct less_equal {
135    bool operator()(const T& x, const T& y) const;
136};
137
138template <class T> // <class T=void> in C++14
139struct logical_and {
140    bool operator()(const T& x, const T& y) const;
141};
142
143template <class T> // <class T=void> in C++14
144struct logical_or {
145    bool operator()(const T& x, const T& y) const;
146};
147
148template <class T> // <class T=void> in C++14
149struct logical_not {
150    bool operator()(const T& x) const;
151};
152
153template <class T> // <class T=void> in C++14
154struct bit_and {
155    T operator()(const T& x, const T& y) const;
156};
157
158template <class T> // <class T=void> in C++14
159struct bit_or {
160    T operator()(const T& x, const T& y) const;
161};
162
163template <class T> // <class T=void> in C++14
164struct bit_xor {
165    T operator()(const T& x, const T& y) const;
166};
167
168template <class T=void> // C++14
169struct bit_not {
170    T operator()(const T& x) const;
171};
172
173struct identity; // C++20
174
175template <class Predicate>
176class unary_negate // deprecated in C++17, removed in C++20
177    : public unary_function<typename Predicate::argument_type, bool>
178{
179public:
180    explicit unary_negate(const Predicate& pred);
181    bool operator()(const typename Predicate::argument_type& x) const;
182};
183
184template <class Predicate> // deprecated in C++17, removed in C++20
185unary_negate<Predicate> not1(const Predicate& pred);
186
187template <class Predicate>
188class binary_negate // deprecated in C++17, removed in C++20
189    : public binary_function<typename Predicate::first_argument_type,
190                             typename Predicate::second_argument_type,
191                             bool>
192{
193public:
194    explicit binary_negate(const Predicate& pred);
195    bool operator()(const typename Predicate::first_argument_type& x,
196                    const typename Predicate::second_argument_type& y) const;
197};
198
199template <class Predicate> // deprecated in C++17, removed in C++20
200binary_negate<Predicate> not2(const Predicate& pred);
201
202template <class F>
203constexpr unspecified not_fn(F&& f); // C++17, constexpr in C++20
204
205template<class T> struct is_bind_expression;
206template<class T> struct is_placeholder;
207
208    // See C++14 20.9.9, Function object binders
209template <class T> inline constexpr bool is_bind_expression_v
210  = is_bind_expression<T>::value; // C++17
211template <class T> inline constexpr int is_placeholder_v
212  = is_placeholder<T>::value; // C++17
213
214
215template<class Fn, class... BoundArgs>
216  constexpr unspecified bind(Fn&&, BoundArgs&&...);  // constexpr in C++20
217template<class R, class Fn, class... BoundArgs>
218  constexpr unspecified bind(Fn&&, BoundArgs&&...);  // constexpr in C++20
219
220template<class F, class... Args>
221 constexpr // constexpr in C++20
222 invoke_result_t<F, Args...> invoke(F&& f, Args&&... args) // C++17
223    noexcept(is_nothrow_invocable_v<F, Args...>);
224
225namespace placeholders {
226  // M is the implementation-defined number of placeholders
227  extern unspecified _1;
228  extern unspecified _2;
229  .
230  .
231  .
232  extern unspecified _Mp;
233}
234
235template <class Operation>
236class binder1st     // deprecated in C++11, removed in C++17
237    : public unary_function<typename Operation::second_argument_type,
238                            typename Operation::result_type>
239{
240protected:
241    Operation                               op;
242    typename Operation::first_argument_type value;
243public:
244    binder1st(const Operation& x, const typename Operation::first_argument_type y);
245    typename Operation::result_type operator()(      typename Operation::second_argument_type& x) const;
246    typename Operation::result_type operator()(const typename Operation::second_argument_type& x) const;
247};
248
249template <class Operation, class T>
250binder1st<Operation> bind1st(const Operation& op, const T& x);  // deprecated in C++11, removed in C++17
251
252template <class Operation>
253class binder2nd     // deprecated in C++11, removed in C++17
254    : public unary_function<typename Operation::first_argument_type,
255                            typename Operation::result_type>
256{
257protected:
258    Operation                                op;
259    typename Operation::second_argument_type value;
260public:
261    binder2nd(const Operation& x, const typename Operation::second_argument_type y);
262    typename Operation::result_type operator()(      typename Operation::first_argument_type& x) const;
263    typename Operation::result_type operator()(const typename Operation::first_argument_type& x) const;
264};
265
266template <class Operation, class T>
267binder2nd<Operation> bind2nd(const Operation& op, const T& x);  // deprecated in C++11, removed in C++17
268
269template <class Arg, class Result>      // deprecated in C++11, removed in C++17
270class pointer_to_unary_function : public unary_function<Arg, Result>
271{
272public:
273    explicit pointer_to_unary_function(Result (*f)(Arg));
274    Result operator()(Arg x) const;
275};
276
277template <class Arg, class Result>
278pointer_to_unary_function<Arg,Result> ptr_fun(Result (*f)(Arg));      // deprecated in C++11, removed in C++17
279
280template <class Arg1, class Arg2, class Result>      // deprecated in C++11, removed in C++17
281class pointer_to_binary_function : public binary_function<Arg1, Arg2, Result>
282{
283public:
284    explicit pointer_to_binary_function(Result (*f)(Arg1, Arg2));
285    Result operator()(Arg1 x, Arg2 y) const;
286};
287
288template <class Arg1, class Arg2, class Result>
289pointer_to_binary_function<Arg1,Arg2,Result> ptr_fun(Result (*f)(Arg1,Arg2));      // deprecated in C++11, removed in C++17
290
291template<class S, class T>      // deprecated in C++11, removed in C++17
292class mem_fun_t : public unary_function<T*, S>
293{
294public:
295    explicit mem_fun_t(S (T::*p)());
296    S operator()(T* p) const;
297};
298
299template<class S, class T, class A>
300class mem_fun1_t : public binary_function<T*, A, S>      // deprecated in C++11, removed in C++17
301{
302public:
303    explicit mem_fun1_t(S (T::*p)(A));
304    S operator()(T* p, A x) const;
305};
306
307template<class S, class T>          mem_fun_t<S,T>    mem_fun(S (T::*f)());      // deprecated in C++11, removed in C++17
308template<class S, class T, class A> mem_fun1_t<S,T,A> mem_fun(S (T::*f)(A));     // deprecated in C++11, removed in C++17
309
310template<class S, class T>
311class mem_fun_ref_t : public unary_function<T, S>      // deprecated in C++11, removed in C++17
312{
313public:
314    explicit mem_fun_ref_t(S (T::*p)());
315    S operator()(T& p) const;
316};
317
318template<class S, class T, class A>
319class mem_fun1_ref_t : public binary_function<T, A, S>      // deprecated in C++11, removed in C++17
320{
321public:
322    explicit mem_fun1_ref_t(S (T::*p)(A));
323    S operator()(T& p, A x) const;
324};
325
326template<class S, class T>          mem_fun_ref_t<S,T>    mem_fun_ref(S (T::*f)());      // deprecated in C++11, removed in C++17
327template<class S, class T, class A> mem_fun1_ref_t<S,T,A> mem_fun_ref(S (T::*f)(A));     // deprecated in C++11, removed in C++17
328
329template <class S, class T>
330class const_mem_fun_t : public unary_function<const T*, S>      // deprecated in C++11, removed in C++17
331{
332public:
333    explicit const_mem_fun_t(S (T::*p)() const);
334    S operator()(const T* p) const;
335};
336
337template <class S, class T, class A>
338class const_mem_fun1_t : public binary_function<const T*, A, S>      // deprecated in C++11, removed in C++17
339{
340public:
341    explicit const_mem_fun1_t(S (T::*p)(A) const);
342    S operator()(const T* p, A x) const;
343};
344
345template <class S, class T>          const_mem_fun_t<S,T>    mem_fun(S (T::*f)() const);      // deprecated in C++11, removed in C++17
346template <class S, class T, class A> const_mem_fun1_t<S,T,A> mem_fun(S (T::*f)(A) const);     // deprecated in C++11, removed in C++17
347
348template <class S, class T>
349class const_mem_fun_ref_t : public unary_function<T, S>      // deprecated in C++11, removed in C++17
350{
351public:
352    explicit const_mem_fun_ref_t(S (T::*p)() const);
353    S operator()(const T& p) const;
354};
355
356template <class S, class T, class A>
357class const_mem_fun1_ref_t : public binary_function<T, A, S>      // deprecated in C++11, removed in C++17
358{
359public:
360    explicit const_mem_fun1_ref_t(S (T::*p)(A) const);
361    S operator()(const T& p, A x) const;
362};
363
364template <class S, class T>          const_mem_fun_ref_t<S,T>    mem_fun_ref(S (T::*f)() const);   // deprecated in C++11, removed in C++17
365template <class S, class T, class A> const_mem_fun1_ref_t<S,T,A> mem_fun_ref(S (T::*f)(A) const);  // deprecated in C++11, removed in C++17
366
367template<class R, class T>
368constexpr unspecified mem_fn(R T::*); // constexpr in C++20
369
370class bad_function_call
371    : public exception
372{
373};
374
375template<class> class function; // undefined
376
377template<class R, class... ArgTypes>
378class function<R(ArgTypes...)>
379  : public unary_function<T1, R>      // iff sizeof...(ArgTypes) == 1 and
380                                      // ArgTypes contains T1
381  : public binary_function<T1, T2, R> // iff sizeof...(ArgTypes) == 2 and
382                                      // ArgTypes contains T1 and T2
383{
384public:
385    typedef R result_type;
386
387    // construct/copy/destroy:
388    function() noexcept;
389    function(nullptr_t) noexcept;
390    function(const function&);
391    function(function&&) noexcept;
392    template<class F>
393      function(F);
394    template<Allocator Alloc>
395      function(allocator_arg_t, const Alloc&) noexcept;            // removed in C++17
396    template<Allocator Alloc>
397      function(allocator_arg_t, const Alloc&, nullptr_t) noexcept; // removed in C++17
398    template<Allocator Alloc>
399      function(allocator_arg_t, const Alloc&, const function&);    // removed in C++17
400    template<Allocator Alloc>
401      function(allocator_arg_t, const Alloc&, function&&);         // removed in C++17
402    template<class F, Allocator Alloc>
403      function(allocator_arg_t, const Alloc&, F);                  // removed in C++17
404
405    function& operator=(const function&);
406    function& operator=(function&&) noexcept;
407    function& operator=(nullptr_t) noexcept;
408    template<class F>
409      function& operator=(F&&);
410    template<class F>
411      function& operator=(reference_wrapper<F>) noexcept;
412
413    ~function();
414
415    // function modifiers:
416    void swap(function&) noexcept;
417    template<class F, class Alloc>
418      void assign(F&&, const Alloc&);                 // Removed in C++17
419
420    // function capacity:
421    explicit operator bool() const noexcept;
422
423    // function invocation:
424    R operator()(ArgTypes...) const;
425
426    // function target access:
427    const std::type_info& target_type() const noexcept;
428    template <typename T>       T* target() noexcept;
429    template <typename T> const T* target() const noexcept;
430};
431
432// Deduction guides
433template<class R, class ...Args>
434function(R(*)(Args...)) -> function<R(Args...)>; // since C++17
435
436template<class F>
437function(F) -> function<see-below>; // since C++17
438
439// Null pointer comparisons:
440template <class R, class ... ArgTypes>
441  bool operator==(const function<R(ArgTypes...)>&, nullptr_t) noexcept;
442
443template <class R, class ... ArgTypes>
444  bool operator==(nullptr_t, const function<R(ArgTypes...)>&) noexcept;
445
446template <class R, class ... ArgTypes>
447  bool operator!=(const function<R(ArgTypes...)>&, nullptr_t) noexcept;
448
449template <class  R, class ... ArgTypes>
450  bool operator!=(nullptr_t, const function<R(ArgTypes...)>&) noexcept;
451
452// specialized algorithms:
453template <class  R, class ... ArgTypes>
454  void swap(function<R(ArgTypes...)>&, function<R(ArgTypes...)>&) noexcept;
455
456template <class T> struct hash;
457
458template <> struct hash<bool>;
459template <> struct hash<char>;
460template <> struct hash<signed char>;
461template <> struct hash<unsigned char>;
462template <> struct hash<char8_t>; // since C++20
463template <> struct hash<char16_t>;
464template <> struct hash<char32_t>;
465template <> struct hash<wchar_t>;
466template <> struct hash<short>;
467template <> struct hash<unsigned short>;
468template <> struct hash<int>;
469template <> struct hash<unsigned int>;
470template <> struct hash<long>;
471template <> struct hash<long long>;
472template <> struct hash<unsigned long>;
473template <> struct hash<unsigned long long>;
474
475template <> struct hash<float>;
476template <> struct hash<double>;
477template <> struct hash<long double>;
478
479template<class T> struct hash<T*>;
480template <> struct hash<nullptr_t>;  // C++17
481
482}  // std
483
484POLICY:  For non-variadic implementations, the number of arguments is limited
485         to 3.  It is hoped that the need for non-variadic implementations
486         will be minimal.
487
488*/
489
490#include <__algorithm/search.h>
491#include <__config>
492#include <__debug>
493#include <__functional/binary_function.h> // TODO: deprecate
494#include <__functional/binary_negate.h>
495#include <__functional/bind_front.h>
496#include <__functional/bind.h>
497#include <__functional/binder1st.h>
498#include <__functional/binder2nd.h>
499#include <__functional/default_searcher.h>
500#include <__functional/function.h>
501#include <__functional/hash.h>
502#include <__functional/identity.h>
503#include <__functional/invoke.h>
504#include <__functional/mem_fn.h> // TODO: deprecate
505#include <__functional/mem_fun_ref.h>
506#include <__functional/not_fn.h>
507#include <__functional/operations.h>
508#include <__functional/pointer_to_binary_function.h>
509#include <__functional/pointer_to_unary_function.h>
510#include <__functional/ranges_operations.h>
511#include <__functional/reference_wrapper.h>
512#include <__functional/unary_function.h> // TODO: deprecate
513#include <__functional/unary_negate.h>
514#include <__functional/unwrap_ref.h>
515#include <__utility/forward.h>
516#include <concepts>
517#include <exception>
518#include <memory>
519#include <tuple>
520#include <type_traits>
521#include <typeinfo>
522#include <utility>
523#include <version>
524
525#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
526#pragma GCC system_header
527#endif
528
529#endif // _LIBCPP_FUNCTIONAL
530