2 //===----------------------------------------------------------------------===//
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
8 //===----------------------------------------------------------------------===//
10 #ifndef _LIBCPP_EXPERIMENTAL_PROPAGATE_CONST
11 #define _LIBCPP_EXPERIMENTAL_PROPAGATE_CONST
14 propagate_const synopsis
16 namespace std { namespace experimental { inline namespace fundamentals_v2 {
19 template <class T> class propagate_const;
21 // [propagate_const.underlying], underlying pointer access
22 constexpr const _Tp& get_underlying(const propagate_const<T>& pt) noexcept;
23 constexpr T& get_underlying(propagate_const<T>& pt) noexcept;
25 // [propagate_const.relational], relational operators
26 template <class T> constexpr bool operator==(const propagate_const<T>& pt, nullptr_t);
27 template <class T> constexpr bool operator==(nullptr_t, const propagate_const<T>& pu);
28 template <class T> constexpr bool operator!=(const propagate_const<T>& pt, nullptr_t);
29 template <class T> constexpr bool operator!=(nullptr_t, const propagate_const<T>& pu);
30 template <class T, class U> constexpr bool operator==(const propagate_const<T>& pt, const propagate_const<_Up>& pu);
31 template <class T, class U> constexpr bool operator!=(const propagate_const<T>& pt, const propagate_const<_Up>& pu);
32 template <class T, class U> constexpr bool operator<(const propagate_const<T>& pt, const propagate_const<_Up>& pu);
33 template <class T, class U> constexpr bool operator>(const propagate_const<T>& pt, const propagate_const<_Up>& pu);
34 template <class T, class U> constexpr bool operator<=(const propagate_const<T>& pt, const propagate_const<_Up>& pu);
35 template <class T, class U> constexpr bool operator>=(const propagate_const<T>& pt, const propagate_const<_Up>& pu);
36 template <class T, class U> constexpr bool operator==(const propagate_const<T>& pt, const _Up& u);
37 template <class T, class U> constexpr bool operator!=(const propagate_const<T>& pt, const _Up& u);
38 template <class T, class U> constexpr bool operator<(const propagate_const<T>& pt, const _Up& u);
39 template <class T, class U> constexpr bool operator>(const propagate_const<T>& pt, const _Up& u);
40 template <class T, class U> constexpr bool operator<=(const propagate_const<T>& pt, const _Up& u);
41 template <class T, class U> constexpr bool operator>=(const propagate_const<T>& pt, const _Up& u);
42 template <class T, class U> constexpr bool operator==(const _Tp& t, const propagate_const<_Up>& pu);
43 template <class T, class U> constexpr bool operator!=(const _Tp& t, const propagate_const<_Up>& pu);
44 template <class T, class U> constexpr bool operator<(const _Tp& t, const propagate_const<_Up>& pu);
45 template <class T, class U> constexpr bool operator>(const _Tp& t, const propagate_const<_Up>& pu);
46 template <class T, class U> constexpr bool operator<=(const _Tp& t, const propagate_const<_Up>& pu);
47 template <class T, class U> constexpr bool operator>=(const _Tp& t, const propagate_const<_Up>& pu);
49 // [propagate_const.algorithms], specialized algorithms
50 template <class T> constexpr void swap(propagate_const<T>& pt, propagate_const<T>& pu) noexcept(see below);
57 typedef remove_reference_t<decltype(*declval<T&>())> element_type;
59 // [propagate_const.ctor], constructors
60 constexpr propagate_const() = default;
61 propagate_const(const propagate_const& p) = delete;
62 constexpr propagate_const(propagate_const&& p) = default;
63 template <class U> EXPLICIT constexpr propagate_const(propagate_const<_Up>&& pu); // see below
64 template <class U> EXPLICIT constexpr propagate_const(U&& u); // see below
66 // [propagate_const.assignment], assignment
67 propagate_const& operator=(const propagate_const& p) = delete;
68 constexpr propagate_const& operator=(propagate_const&& p) = default;
69 template <class U> constexpr propagate_const& operator=(propagate_const<_Up>&& pu);
70 template <class U> constexpr propagate_const& operator=(U&& u); // see below
72 // [propagate_const.const_observers], const observers
73 explicit constexpr operator bool() const;
74 constexpr const element_type* operator->() const;
75 constexpr operator const element_type*() const; // Not always defined
76 constexpr const element_type& operator*() const;
77 constexpr const element_type* get() const;
79 // [propagate_const.non_const_observers], non-const observers
80 constexpr element_type* operator->();
81 constexpr operator element_type*(); // Not always defined
82 constexpr element_type& operator*();
83 constexpr element_type* get();
85 // [propagate_const.modifiers], modifiers
86 constexpr void swap(propagate_const& pt) noexcept(see below)
89 T t_; // exposition only
92 } // namespace fundamentals_v2
93 } // namespace experimental
95 // [propagate_const.hash], hash support
96 template <class T> struct hash<experimental::propagate_const<T>>;
98 // [propagate_const.comparison_function_objects], comparison function objects
99 template <class T> struct equal_to<experimental::propagate_const<T>>;
100 template <class T> struct not_equal_to<experimental::propagate_const<T>>;
101 template <class T> struct less<experimental::propagate_const<T>>;
102 template <class T> struct greater<experimental::propagate_const<T>>;
103 template <class T> struct less_equal<experimental::propagate_const<T>>;
104 template <class T> struct greater_equal<experimental::propagate_const<T>>;
110 #include <__cxx03/__functional/operations.h>
111 #include <__cxx03/__fwd/functional.h>
112 #include <__cxx03/__type_traits/conditional.h>
113 #include <__cxx03/__type_traits/decay.h>
114 #include <__cxx03/__type_traits/enable_if.h>
115 #include <__cxx03/__type_traits/is_array.h>
116 #include <__cxx03/__type_traits/is_constructible.h>
117 #include <__cxx03/__type_traits/is_convertible.h>
118 #include <__cxx03/__type_traits/is_function.h>
119 #include <__cxx03/__type_traits/is_pointer.h>
120 #include <__cxx03/__type_traits/is_reference.h>
121 #include <__cxx03/__type_traits/is_same.h>
122 #include <__cxx03/__type_traits/is_swappable.h>
123 #include <__cxx03/__type_traits/remove_cv.h>
124 #include <__cxx03/__type_traits/remove_pointer.h>
125 #include <__cxx03/__type_traits/remove_reference.h>
126 #include <__cxx03/__utility/declval.h>
127 #include <__cxx03/__utility/forward.h>
128 #include <__cxx03/__utility/move.h>
129 #include <__cxx03/__utility/swap.h>
130 #include <__cxx03/cstddef>
131 #include <__cxx03/experimental/__config>
133 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
134 # pragma GCC system_header
138 #include <__cxx03/__undef_macros>
140 #if _LIBCPP_STD_VER >= 14
142 _LIBCPP_BEGIN_NAMESPACE_LFTS_V2
145 class propagate_const;
148 inline _LIBCPP_HIDE_FROM_ABI constexpr const _Up& get_underlying(const propagate_const<_Up>& __pu) _NOEXCEPT;
151 inline _LIBCPP_HIDE_FROM_ABI constexpr _Up& get_underlying(propagate_const<_Up>& __pu) _NOEXCEPT;
154 class propagate_const {
156 typedef remove_reference_t<decltype(*std::declval<_Tp&>())> element_type;
158 static_assert(!is_array<_Tp>::value, "Instantiation of propagate_const with an array type is ill-formed.");
159 static_assert(!is_reference<_Tp>::value, "Instantiation of propagate_const with a reference type is ill-formed.");
160 static_assert(!(is_pointer<_Tp>::value && is_function<__remove_pointer_t<_Tp> >::value),
161 "Instantiation of propagate_const with a function-pointer type is ill-formed.");
162 static_assert(!(is_pointer<_Tp>::value && is_same<__remove_cv_t<__remove_pointer_t<_Tp> >, void>::value),
163 "Instantiation of propagate_const with a pointer to (possibly cv-qualified) void is ill-formed.");
167 static _LIBCPP_HIDE_FROM_ABI constexpr element_type* __get_pointer(_Up* __u) {
172 static _LIBCPP_HIDE_FROM_ABI constexpr element_type* __get_pointer(_Up& __u) {
173 return __get_pointer(__u.get());
177 static _LIBCPP_HIDE_FROM_ABI constexpr const element_type* __get_pointer(const _Up* __u) {
182 static _LIBCPP_HIDE_FROM_ABI constexpr const element_type* __get_pointer(const _Up& __u) {
183 return __get_pointer(__u.get());
187 struct __is_propagate_const : false_type {};
190 struct __is_propagate_const<propagate_const<_Up>> : true_type {};
196 friend constexpr const _Up& experimental::fundamentals_v2::get_underlying(const propagate_const<_Up>& __pu) _NOEXCEPT;
198 friend constexpr _Up& experimental::fundamentals_v2::get_underlying(propagate_const<_Up>& __pu) _NOEXCEPT;
200 _LIBCPP_HIDE_FROM_ABI constexpr propagate_const() = default;
202 propagate_const(const propagate_const&) = delete;
204 _LIBCPP_HIDE_FROM_ABI constexpr propagate_const(propagate_const&&) = default;
207 enable_if_t<!is_convertible<_Up, _Tp>::value && is_constructible<_Tp, _Up&&>::value, bool> = true>
208 explicit _LIBCPP_HIDE_FROM_ABI constexpr propagate_const(propagate_const<_Up>&& __pu)
209 : __t_(std::move(experimental::get_underlying(__pu))) {}
212 enable_if_t<is_convertible<_Up&&, _Tp>::value && is_constructible<_Tp, _Up&&>::value, bool> = false>
213 _LIBCPP_HIDE_FROM_ABI constexpr propagate_const(propagate_const<_Up>&& __pu)
214 : __t_(std::move(experimental::get_underlying(__pu))) {}
217 enable_if_t<!is_convertible<_Up&&, _Tp>::value && is_constructible<_Tp, _Up&&>::value &&
218 !__is_propagate_const<decay_t<_Up>>::value,
220 explicit _LIBCPP_HIDE_FROM_ABI constexpr propagate_const(_Up&& __u) : __t_(std::forward<_Up>(__u)) {}
223 enable_if_t<is_convertible<_Up&&, _Tp>::value && is_constructible<_Tp, _Up&&>::value &&
224 !__is_propagate_const<decay_t<_Up>>::value,
226 _LIBCPP_HIDE_FROM_ABI constexpr propagate_const(_Up&& __u) : __t_(std::forward<_Up>(__u)) {}
228 propagate_const& operator=(const propagate_const&) = delete;
230 _LIBCPP_HIDE_FROM_ABI constexpr propagate_const& operator=(propagate_const&&) = default;
233 _LIBCPP_HIDE_FROM_ABI constexpr propagate_const& operator=(propagate_const<_Up>&& __pu) {
234 __t_ = std::move(experimental::get_underlying(__pu));
238 template <class _Up, class _Vp = enable_if_t<!__is_propagate_const<decay_t<_Up>>::value>>
239 _LIBCPP_HIDE_FROM_ABI constexpr propagate_const& operator=(_Up&& __u) {
240 __t_ = std::forward<_Up>(__u);
244 _LIBCPP_HIDE_FROM_ABI constexpr const element_type* get() const { return __get_pointer(__t_); }
246 _LIBCPP_HIDE_FROM_ABI constexpr element_type* get() { return __get_pointer(__t_); }
248 _LIBCPP_HIDE_FROM_ABI explicit constexpr operator bool() const { return get() != nullptr; }
250 _LIBCPP_HIDE_FROM_ABI constexpr const element_type* operator->() const { return get(); }
252 template <class _Dummy = _Tp, class _Up = enable_if_t<is_convertible< const _Dummy, const element_type*>::value>>
253 _LIBCPP_HIDE_FROM_ABI constexpr operator const element_type*() const {
257 _LIBCPP_HIDE_FROM_ABI constexpr const element_type& operator*() const { return *get(); }
259 _LIBCPP_HIDE_FROM_ABI constexpr element_type* operator->() { return get(); }
261 template <class _Dummy = _Tp, class _Up = enable_if_t< is_convertible<_Dummy, element_type*>::value>>
262 _LIBCPP_HIDE_FROM_ABI constexpr operator element_type*() {
266 _LIBCPP_HIDE_FROM_ABI constexpr element_type& operator*() { return *get(); }
268 _LIBCPP_HIDE_FROM_ABI constexpr void swap(propagate_const& __pt) noexcept(__is_nothrow_swappable_v<_Tp>) {
270 swap(__t_, __pt.__t_);
275 _LIBCPP_HIDE_FROM_ABI constexpr bool operator==(const propagate_const<_Tp>& __pt, nullptr_t) {
276 return experimental::get_underlying(__pt) == nullptr;
280 _LIBCPP_HIDE_FROM_ABI constexpr bool operator==(nullptr_t, const propagate_const<_Tp>& __pt) {
281 return nullptr == experimental::get_underlying(__pt);
285 _LIBCPP_HIDE_FROM_ABI constexpr bool operator!=(const propagate_const<_Tp>& __pt, nullptr_t) {
286 return experimental::get_underlying(__pt) != nullptr;
290 _LIBCPP_HIDE_FROM_ABI constexpr bool operator!=(nullptr_t, const propagate_const<_Tp>& __pt) {
291 return nullptr != experimental::get_underlying(__pt);
294 template <class _Tp, class _Up>
295 _LIBCPP_HIDE_FROM_ABI constexpr bool operator==(const propagate_const<_Tp>& __pt, const propagate_const<_Up>& __pu) {
296 return experimental::get_underlying(__pt) == experimental::get_underlying(__pu);
299 template <class _Tp, class _Up>
300 _LIBCPP_HIDE_FROM_ABI constexpr bool operator!=(const propagate_const<_Tp>& __pt, const propagate_const<_Up>& __pu) {
301 return experimental::get_underlying(__pt) != experimental::get_underlying(__pu);
304 template <class _Tp, class _Up>
305 _LIBCPP_HIDE_FROM_ABI constexpr bool operator<(const propagate_const<_Tp>& __pt, const propagate_const<_Up>& __pu) {
306 return experimental::get_underlying(__pt) < experimental::get_underlying(__pu);
309 template <class _Tp, class _Up>
310 _LIBCPP_HIDE_FROM_ABI constexpr bool operator>(const propagate_const<_Tp>& __pt, const propagate_const<_Up>& __pu) {
311 return experimental::get_underlying(__pt) > experimental::get_underlying(__pu);
314 template <class _Tp, class _Up>
315 _LIBCPP_HIDE_FROM_ABI constexpr bool operator<=(const propagate_const<_Tp>& __pt, const propagate_const<_Up>& __pu) {
316 return experimental::get_underlying(__pt) <= experimental::get_underlying(__pu);
319 template <class _Tp, class _Up>
320 _LIBCPP_HIDE_FROM_ABI constexpr bool operator>=(const propagate_const<_Tp>& __pt, const propagate_const<_Up>& __pu) {
321 return experimental::get_underlying(__pt) >= experimental::get_underlying(__pu);
324 template <class _Tp, class _Up>
325 _LIBCPP_HIDE_FROM_ABI constexpr bool operator==(const propagate_const<_Tp>& __pt, const _Up& __u) {
326 return experimental::get_underlying(__pt) == __u;
329 template <class _Tp, class _Up>
330 _LIBCPP_HIDE_FROM_ABI constexpr bool operator!=(const propagate_const<_Tp>& __pt, const _Up& __u) {
331 return experimental::get_underlying(__pt) != __u;
334 template <class _Tp, class _Up>
335 _LIBCPP_HIDE_FROM_ABI constexpr bool operator<(const propagate_const<_Tp>& __pt, const _Up& __u) {
336 return experimental::get_underlying(__pt) < __u;
339 template <class _Tp, class _Up>
340 _LIBCPP_HIDE_FROM_ABI constexpr bool operator>(const propagate_const<_Tp>& __pt, const _Up& __u) {
341 return experimental::get_underlying(__pt) > __u;
344 template <class _Tp, class _Up>
345 _LIBCPP_HIDE_FROM_ABI constexpr bool operator<=(const propagate_const<_Tp>& __pt, const _Up& __u) {
346 return experimental::get_underlying(__pt) <= __u;
349 template <class _Tp, class _Up>
350 _LIBCPP_HIDE_FROM_ABI constexpr bool operator>=(const propagate_const<_Tp>& __pt, const _Up& __u) {
351 return experimental::get_underlying(__pt) >= __u;
354 template <class _Tp, class _Up>
355 _LIBCPP_HIDE_FROM_ABI constexpr bool operator==(const _Tp& __t, const propagate_const<_Up>& __pu) {
356 return __t == experimental::get_underlying(__pu);
359 template <class _Tp, class _Up>
360 _LIBCPP_HIDE_FROM_ABI constexpr bool operator!=(const _Tp& __t, const propagate_const<_Up>& __pu) {
361 return __t != experimental::get_underlying(__pu);
364 template <class _Tp, class _Up>
365 _LIBCPP_HIDE_FROM_ABI constexpr bool operator<(const _Tp& __t, const propagate_const<_Up>& __pu) {
366 return __t < experimental::get_underlying(__pu);
369 template <class _Tp, class _Up>
370 _LIBCPP_HIDE_FROM_ABI constexpr bool operator>(const _Tp& __t, const propagate_const<_Up>& __pu) {
371 return __t > experimental::get_underlying(__pu);
374 template <class _Tp, class _Up>
375 _LIBCPP_HIDE_FROM_ABI constexpr bool operator<=(const _Tp& __t, const propagate_const<_Up>& __pu) {
376 return __t <= experimental::get_underlying(__pu);
379 template <class _Tp, class _Up>
380 _LIBCPP_HIDE_FROM_ABI constexpr bool operator>=(const _Tp& __t, const propagate_const<_Up>& __pu) {
381 return __t >= experimental::get_underlying(__pu);
385 _LIBCPP_HIDE_FROM_ABI constexpr void
386 swap(propagate_const<_Tp>& __pc1, propagate_const<_Tp>& __pc2) noexcept(__is_nothrow_swappable_v<_Tp>) {
391 constexpr const _Tp& get_underlying(const propagate_const<_Tp>& __pt) _NOEXCEPT {
396 constexpr _Tp& get_underlying(propagate_const<_Tp>& __pt) _NOEXCEPT {
400 _LIBCPP_END_NAMESPACE_LFTS_V2
402 _LIBCPP_BEGIN_NAMESPACE_STD
405 struct hash<experimental::propagate_const<_Tp>> {
406 typedef size_t result_type;
407 typedef experimental::propagate_const<_Tp> argument_type;
409 _LIBCPP_HIDE_FROM_ABI size_t operator()(const experimental::propagate_const<_Tp>& __pc1) const {
410 return std::hash<_Tp>()(experimental::get_underlying(__pc1));
415 struct equal_to<experimental::propagate_const<_Tp>> {
416 typedef experimental::propagate_const<_Tp> first_argument_type;
417 typedef experimental::propagate_const<_Tp> second_argument_type;
419 _LIBCPP_HIDE_FROM_ABI bool
420 operator()(const experimental::propagate_const<_Tp>& __pc1, const experimental::propagate_const<_Tp>& __pc2) const {
421 return std::equal_to<_Tp>()(experimental::get_underlying(__pc1), experimental::get_underlying(__pc2));
426 struct not_equal_to<experimental::propagate_const<_Tp>> {
427 typedef experimental::propagate_const<_Tp> first_argument_type;
428 typedef experimental::propagate_const<_Tp> second_argument_type;
430 _LIBCPP_HIDE_FROM_ABI bool
431 operator()(const experimental::propagate_const<_Tp>& __pc1, const experimental::propagate_const<_Tp>& __pc2) const {
432 return std::not_equal_to<_Tp>()(experimental::get_underlying(__pc1), experimental::get_underlying(__pc2));
437 struct less<experimental::propagate_const<_Tp>> {
438 typedef experimental::propagate_const<_Tp> first_argument_type;
439 typedef experimental::propagate_const<_Tp> second_argument_type;
441 _LIBCPP_HIDE_FROM_ABI bool
442 operator()(const experimental::propagate_const<_Tp>& __pc1, const experimental::propagate_const<_Tp>& __pc2) const {
443 return std::less<_Tp>()(experimental::get_underlying(__pc1), experimental::get_underlying(__pc2));
448 struct greater<experimental::propagate_const<_Tp>> {
449 typedef experimental::propagate_const<_Tp> first_argument_type;
450 typedef experimental::propagate_const<_Tp> second_argument_type;
452 _LIBCPP_HIDE_FROM_ABI bool
453 operator()(const experimental::propagate_const<_Tp>& __pc1, const experimental::propagate_const<_Tp>& __pc2) const {
454 return std::greater<_Tp>()(experimental::get_underlying(__pc1), experimental::get_underlying(__pc2));
459 struct less_equal<experimental::propagate_const<_Tp>> {
460 typedef experimental::propagate_const<_Tp> first_argument_type;
461 typedef experimental::propagate_const<_Tp> second_argument_type;
463 _LIBCPP_HIDE_FROM_ABI bool
464 operator()(const experimental::propagate_const<_Tp>& __pc1, const experimental::propagate_const<_Tp>& __pc2) const {
465 return std::less_equal<_Tp>()(experimental::get_underlying(__pc1), experimental::get_underlying(__pc2));
470 struct greater_equal<experimental::propagate_const<_Tp>> {
471 typedef experimental::propagate_const<_Tp> first_argument_type;
472 typedef experimental::propagate_const<_Tp> second_argument_type;
474 _LIBCPP_HIDE_FROM_ABI bool
475 operator()(const experimental::propagate_const<_Tp>& __pc1, const experimental::propagate_const<_Tp>& __pc2) const {
476 return std::greater_equal<_Tp>()(experimental::get_underlying(__pc1), experimental::get_underlying(__pc2));
480 _LIBCPP_END_NAMESPACE_STD
482 #endif // _LIBCPP_STD_VER >= 14
486 #if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
487 # include <__cxx03/type_traits>
490 #endif // _LIBCPP_EXPERIMENTAL_PROPAGATE_CONST