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_TYPE_TRAITS
11 #define _LIBCPP_TYPE_TRAITS
20 template <class T, T v> struct integral_constant;
21 typedef integral_constant<bool, true> true_type; // C++11
22 typedef integral_constant<bool, false> false_type; // C++11
24 template <bool B> // C++14
25 using bool_constant = integral_constant<bool, B>; // C++14
26 typedef bool_constant<true> true_type; // C++14
27 typedef bool_constant<false> false_type; // C++14
30 template <bool, class T = void> struct enable_if;
31 template <bool, class T, class F> struct conditional;
33 // Primary classification traits:
34 template <class T> struct is_void;
35 template <class T> struct is_null_pointer; // C++14
36 template <class T> struct is_integral;
37 template <class T> struct is_floating_point;
38 template <class T> struct is_array;
39 template <class T> struct is_pointer;
40 template <class T> struct is_lvalue_reference;
41 template <class T> struct is_rvalue_reference;
42 template <class T> struct is_member_object_pointer;
43 template <class T> struct is_member_function_pointer;
44 template <class T> struct is_enum;
45 template <class T> struct is_union;
46 template <class T> struct is_class;
47 template <class T> struct is_function;
49 // Secondary classification traits:
50 template <class T> struct is_reference;
51 template <class T> struct is_arithmetic;
52 template <class T> struct is_fundamental;
53 template <class T> struct is_member_pointer;
54 template <class T> struct is_scoped_enum; // C++23
55 template <class T> struct is_scalar;
56 template <class T> struct is_object;
57 template <class T> struct is_compound;
59 // Const-volatile properties and transformations:
60 template <class T> struct is_const;
61 template <class T> struct is_volatile;
62 template <class T> struct remove_const;
63 template <class T> struct remove_volatile;
64 template <class T> struct remove_cv;
65 template <class T> struct add_const;
66 template <class T> struct add_volatile;
67 template <class T> struct add_cv;
69 // Reference transformations:
70 template <class T> struct remove_reference;
71 template <class T> struct add_lvalue_reference;
72 template <class T> struct add_rvalue_reference;
74 // Pointer transformations:
75 template <class T> struct remove_pointer;
76 template <class T> struct add_pointer;
78 template<class T> struct type_identity; // C++20
80 using type_identity_t = typename type_identity<T>::type; // C++20
82 // Integral properties:
83 template <class T> struct is_signed;
84 template <class T> struct is_unsigned;
85 template <class T> struct make_signed;
86 template <class T> struct make_unsigned;
88 // Array properties and transformations:
89 template <class T> struct rank;
90 template <class T, unsigned I = 0> struct extent;
91 template <class T> struct remove_extent;
92 template <class T> struct remove_all_extents;
94 template <class T> struct is_bounded_array; // C++20
95 template <class T> struct is_unbounded_array; // C++20
97 // Member introspection:
98 template <class T> struct is_pod;
99 template <class T> struct is_trivial;
100 template <class T> struct is_trivially_copyable;
101 template <class T> struct is_standard_layout;
102 template <class T> struct is_literal_type; // Deprecated in C++17; removed in C++20
103 template <class T> struct is_empty;
104 template <class T> struct is_polymorphic;
105 template <class T> struct is_abstract;
106 template <class T> struct is_final; // C++14
107 template <class T> struct is_aggregate; // C++17
109 template <class T, class... Args> struct is_constructible;
110 template <class T> struct is_default_constructible;
111 template <class T> struct is_copy_constructible;
112 template <class T> struct is_move_constructible;
113 template <class T, class U> struct is_assignable;
114 template <class T> struct is_copy_assignable;
115 template <class T> struct is_move_assignable;
116 template <class T, class U> struct is_swappable_with; // C++17
117 template <class T> struct is_swappable; // C++17
118 template <class T> struct is_destructible;
120 template <class T, class... Args> struct is_trivially_constructible;
121 template <class T> struct is_trivially_default_constructible;
122 template <class T> struct is_trivially_copy_constructible;
123 template <class T> struct is_trivially_move_constructible;
124 template <class T, class U> struct is_trivially_assignable;
125 template <class T> struct is_trivially_copy_assignable;
126 template <class T> struct is_trivially_move_assignable;
127 template <class T> struct is_trivially_destructible;
129 template <class T, class... Args> struct is_nothrow_constructible;
130 template <class T> struct is_nothrow_default_constructible;
131 template <class T> struct is_nothrow_copy_constructible;
132 template <class T> struct is_nothrow_move_constructible;
133 template <class T, class U> struct is_nothrow_assignable;
134 template <class T> struct is_nothrow_copy_assignable;
135 template <class T> struct is_nothrow_move_assignable;
136 template <class T, class U> struct is_nothrow_swappable_with; // C++17
137 template <class T> struct is_nothrow_swappable; // C++17
138 template <class T> struct is_nothrow_destructible;
140 template<class T> struct is_implicit_lifetime; // Since C++23
142 template <class T> struct has_virtual_destructor;
144 template<class T> struct has_unique_object_representations; // C++17
146 // Relationships between types:
147 template <class T, class U> struct is_same;
148 template <class Base, class Derived> struct is_base_of;
149 template <class Base, class Derived> struct is_virtual_base_of; // C++26
151 template <class From, class To> struct is_convertible;
152 template <typename From, typename To> struct is_nothrow_convertible; // C++20
153 template <typename From, typename To> inline constexpr bool is_nothrow_convertible_v; // C++20
155 template <class Fn, class... ArgTypes> struct is_invocable;
156 template <class R, class Fn, class... ArgTypes> struct is_invocable_r;
158 template <class Fn, class... ArgTypes> struct is_nothrow_invocable;
159 template <class R, class Fn, class... ArgTypes> struct is_nothrow_invocable_r;
161 // Alignment properties and transformations:
162 template <class T> struct alignment_of;
163 template <size_t Len, size_t Align = most_stringent_alignment_requirement>
164 struct aligned_storage; // deprecated in C++23
165 template <size_t Len, class... Types> struct aligned_union; // deprecated in C++23
166 template <class T> struct remove_cvref; // C++20
168 template <class T> struct decay;
169 template <class... T> struct common_type;
170 template <class T> struct underlying_type;
171 template <class> class result_of; // undefined; deprecated in C++17; removed in C++20
172 template <class Fn, class... ArgTypes> class result_of<Fn(ArgTypes...)>; // deprecated in C++17; removed in C++20
173 template <class Fn, class... ArgTypes> struct invoke_result; // C++17
175 // const-volatile modifications:
177 using remove_const_t = typename remove_const<T>::type; // C++14
179 using remove_volatile_t = typename remove_volatile<T>::type; // C++14
181 using remove_cv_t = typename remove_cv<T>::type; // C++14
183 using add_const_t = typename add_const<T>::type; // C++14
185 using add_volatile_t = typename add_volatile<T>::type; // C++14
187 using add_cv_t = typename add_cv<T>::type; // C++14
189 // reference modifications:
191 using remove_reference_t = typename remove_reference<T>::type; // C++14
193 using add_lvalue_reference_t = typename add_lvalue_reference<T>::type; // C++14
195 using add_rvalue_reference_t = typename add_rvalue_reference<T>::type; // C++14
197 // sign modifications:
199 using make_signed_t = typename make_signed<T>::type; // C++14
201 using make_unsigned_t = typename make_unsigned<T>::type; // C++14
203 // array modifications:
205 using remove_extent_t = typename remove_extent<T>::type; // C++14
207 using remove_all_extents_t = typename remove_all_extents<T>::type; // C++14
210 inline constexpr bool is_bounded_array_v
211 = is_bounded_array<T>::value; // C++20
212 inline constexpr bool is_unbounded_array_v
213 = is_unbounded_array<T>::value; // C++20
215 // pointer modifications:
217 using remove_pointer_t = typename remove_pointer<T>::type; // C++14
219 using add_pointer_t = typename add_pointer<T>::type; // C++14
221 // other transformations:
222 template <size_t Len, size_t Align=default-alignment>
223 using aligned_storage_t = typename aligned_storage<Len,Align>::type; // C++14
224 template <size_t Len, class... Types>
225 using aligned_union_t = typename aligned_union<Len,Types...>::type; // C++14
227 using remove_cvref_t = typename remove_cvref<T>::type; // C++20
229 using decay_t = typename decay<T>::type; // C++14
230 template <bool b, class T=void>
231 using enable_if_t = typename enable_if<b,T>::type; // C++14
232 template <bool b, class T, class F>
233 using conditional_t = typename conditional<b,T,F>::type; // C++14
234 template <class... T>
235 using common_type_t = typename common_type<T...>::type; // C++14
237 using underlying_type_t = typename underlying_type<T>::type; // C++14
239 using result_of_t = typename result_of<T>::type; // C++14; deprecated in C++17; removed in C++20
240 template <class Fn, class... ArgTypes>
241 using invoke_result_t = typename invoke_result<Fn, ArgTypes...>::type; // C++17
244 using void_t = void; // C++17
246 // See C++14 20.10.4.1, primary type categories
247 template <class T> inline constexpr bool is_void_v
248 = is_void<T>::value; // C++17
249 template <class T> inline constexpr bool is_null_pointer_v
250 = is_null_pointer<T>::value; // C++17
251 template <class T> inline constexpr bool is_integral_v
252 = is_integral<T>::value; // C++17
253 template <class T> inline constexpr bool is_floating_point_v
254 = is_floating_point<T>::value; // C++17
255 template <class T> inline constexpr bool is_array_v
256 = is_array<T>::value; // C++17
257 template <class T> inline constexpr bool is_pointer_v
258 = is_pointer<T>::value; // C++17
259 template <class T> inline constexpr bool is_lvalue_reference_v
260 = is_lvalue_reference<T>::value; // C++17
261 template <class T> inline constexpr bool is_rvalue_reference_v
262 = is_rvalue_reference<T>::value; // C++17
263 template <class T> inline constexpr bool is_member_object_pointer_v
264 = is_member_object_pointer<T>::value; // C++17
265 template <class T> inline constexpr bool is_member_function_pointer_v
266 = is_member_function_pointer<T>::value; // C++17
267 template <class T> inline constexpr bool is_enum_v
268 = is_enum<T>::value; // C++17
269 template <class T> inline constexpr bool is_union_v
270 = is_union<T>::value; // C++17
271 template <class T> inline constexpr bool is_class_v
272 = is_class<T>::value; // C++17
273 template <class T> inline constexpr bool is_function_v
274 = is_function<T>::value; // C++17
276 // See C++14 20.10.4.2, composite type categories
277 template <class T> inline constexpr bool is_reference_v
278 = is_reference<T>::value; // C++17
279 template <class T> inline constexpr bool is_arithmetic_v
280 = is_arithmetic<T>::value; // C++17
281 template <class T> inline constexpr bool is_fundamental_v
282 = is_fundamental<T>::value; // C++17
283 template <class T> inline constexpr bool is_object_v
284 = is_object<T>::value; // C++17
285 template <class T> inline constexpr bool is_scalar_v
286 = is_scalar<T>::value; // C++17
287 template <class T> inline constexpr bool is_compound_v
288 = is_compound<T>::value; // C++17
289 template <class T> inline constexpr bool is_member_pointer_v
290 = is_member_pointer<T>::value; // C++17
291 template <class T> inline constexpr bool is_scoped_enum_v
292 = is_scoped_enum<T>::value; // C++23
294 // See C++14 20.10.4.3, type properties
295 template <class T> inline constexpr bool is_const_v
296 = is_const<T>::value; // C++17
297 template <class T> inline constexpr bool is_volatile_v
298 = is_volatile<T>::value; // C++17
299 template <class T> inline constexpr bool is_trivial_v
300 = is_trivial<T>::value; // C++17
301 template <class T> inline constexpr bool is_trivially_copyable_v
302 = is_trivially_copyable<T>::value; // C++17
303 template <class T> inline constexpr bool is_standard_layout_v
304 = is_standard_layout<T>::value; // C++17
305 template <class T> inline constexpr bool is_pod_v
306 = is_pod<T>::value; // C++17
307 template <class T> inline constexpr bool is_literal_type_v
308 = is_literal_type<T>::value; // C++17; deprecated in C++17; removed in C++20
309 template <class T> inline constexpr bool is_empty_v
310 = is_empty<T>::value; // C++17
311 template <class T> inline constexpr bool is_polymorphic_v
312 = is_polymorphic<T>::value; // C++17
313 template <class T> inline constexpr bool is_abstract_v
314 = is_abstract<T>::value; // C++17
315 template <class T> inline constexpr bool is_final_v
316 = is_final<T>::value; // C++17
317 template <class T> inline constexpr bool is_aggregate_v
318 = is_aggregate<T>::value; // C++17
319 template <class T> inline constexpr bool is_signed_v
320 = is_signed<T>::value; // C++17
321 template <class T> inline constexpr bool is_unsigned_v
322 = is_unsigned<T>::value; // C++17
323 template <class T, class... Args> inline constexpr bool is_constructible_v
324 = is_constructible<T, Args...>::value; // C++17
325 template <class T> inline constexpr bool is_default_constructible_v
326 = is_default_constructible<T>::value; // C++17
327 template <class T> inline constexpr bool is_copy_constructible_v
328 = is_copy_constructible<T>::value; // C++17
329 template <class T> inline constexpr bool is_move_constructible_v
330 = is_move_constructible<T>::value; // C++17
331 template <class T, class U> inline constexpr bool is_assignable_v
332 = is_assignable<T, U>::value; // C++17
333 template <class T> inline constexpr bool is_copy_assignable_v
334 = is_copy_assignable<T>::value; // C++17
335 template <class T> inline constexpr bool is_move_assignable_v
336 = is_move_assignable<T>::value; // C++17
337 template <class T, class U> inline constexpr bool is_swappable_with_v
338 = is_swappable_with<T, U>::value; // C++17
339 template <class T> inline constexpr bool is_swappable_v
340 = is_swappable<T>::value; // C++17
341 template <class T> inline constexpr bool is_destructible_v
342 = is_destructible<T>::value; // C++17
343 template <class T, class... Args> inline constexpr bool is_trivially_constructible_v
344 = is_trivially_constructible<T, Args...>::value; // C++17
345 template <class T> inline constexpr bool is_trivially_default_constructible_v
346 = is_trivially_default_constructible<T>::value; // C++17
347 template <class T> inline constexpr bool is_trivially_copy_constructible_v
348 = is_trivially_copy_constructible<T>::value; // C++17
349 template <class T> inline constexpr bool is_trivially_move_constructible_v
350 = is_trivially_move_constructible<T>::value; // C++17
351 template <class T, class U> inline constexpr bool is_trivially_assignable_v
352 = is_trivially_assignable<T, U>::value; // C++17
353 template <class T> inline constexpr bool is_trivially_copy_assignable_v
354 = is_trivially_copy_assignable<T>::value; // C++17
355 template <class T> inline constexpr bool is_trivially_move_assignable_v
356 = is_trivially_move_assignable<T>::value; // C++17
357 template <class T> inline constexpr bool is_trivially_destructible_v
358 = is_trivially_destructible<T>::value; // C++17
359 template <class T, class... Args> inline constexpr bool is_nothrow_constructible_v
360 = is_nothrow_constructible<T, Args...>::value; // C++17
361 template <class T> inline constexpr bool is_nothrow_default_constructible_v
362 = is_nothrow_default_constructible<T>::value; // C++17
363 template <class T> inline constexpr bool is_nothrow_copy_constructible_v
364 = is_nothrow_copy_constructible<T>::value; // C++17
365 template <class T> inline constexpr bool is_nothrow_move_constructible_v
366 = is_nothrow_move_constructible<T>::value; // C++17
367 template <class T, class U> inline constexpr bool is_nothrow_assignable_v
368 = is_nothrow_assignable<T, U>::value; // C++17
369 template <class T> inline constexpr bool is_nothrow_copy_assignable_v
370 = is_nothrow_copy_assignable<T>::value; // C++17
371 template <class T> inline constexpr bool is_nothrow_move_assignable_v
372 = is_nothrow_move_assignable<T>::value; // C++17
373 template <class T, class U> inline constexpr bool is_nothrow_swappable_with_v
374 = is_nothrow_swappable_with<T, U>::value; // C++17
375 template <class T> inline constexpr bool is_nothrow_swappable_v
376 = is_nothrow_swappable<T>::value; // C++17
377 template <class T> inline constexpr bool is_nothrow_destructible_v
378 = is_nothrow_destructible<T>::value; // C++17
380 constexpr bool is_implicit_lifetime_v = is_implicit_lifetime<T>::value; // Since C++23
381 template <class T> inline constexpr bool has_virtual_destructor_v
382 = has_virtual_destructor<T>::value; // C++17
383 template<class T> inline constexpr bool has_unique_object_representations_v // C++17
384 = has_unique_object_representations<T>::value;
386 // See C++14 20.10.5, type property queries
387 template <class T> inline constexpr size_t alignment_of_v
388 = alignment_of<T>::value; // C++17
389 template <class T> inline constexpr size_t rank_v
390 = rank<T>::value; // C++17
391 template <class T, unsigned I = 0> inline constexpr size_t extent_v
392 = extent<T, I>::value; // C++17
394 // See C++14 20.10.6, type relations
395 template <class T, class U> inline constexpr bool is_same_v
396 = is_same<T, U>::value; // C++17
397 template <class Base, class Derived> inline constexpr bool is_base_of_v
398 = is_base_of<Base, Derived>::value; // C++17
399 template <class Base, class Derived> inline constexpr bool is_virtual_base_of_v
400 = is_virtual_base_of<Base, Derived>::value; // C++26
401 template <class From, class To> inline constexpr bool is_convertible_v
402 = is_convertible<From, To>::value; // C++17
403 template <class Fn, class... ArgTypes> inline constexpr bool is_invocable_v
404 = is_invocable<Fn, ArgTypes...>::value; // C++17
405 template <class R, class Fn, class... ArgTypes> inline constexpr bool is_invocable_r_v
406 = is_invocable_r<R, Fn, ArgTypes...>::value; // C++17
407 template <class Fn, class... ArgTypes> inline constexpr bool is_nothrow_invocable_v
408 = is_nothrow_invocable<Fn, ArgTypes...>::value; // C++17
409 template <class R, class Fn, class... ArgTypes> inline constexpr bool is_nothrow_invocable_r_v
410 = is_nothrow_invocable_r<R, Fn, ArgTypes...>::value; // C++17
412 // [meta.logical], logical operator traits:
413 template<class... B> struct conjunction; // C++17
415 inline constexpr bool conjunction_v = conjunction<B...>::value; // C++17
416 template<class... B> struct disjunction; // C++17
418 inline constexpr bool disjunction_v = disjunction<B...>::value; // C++17
419 template<class B> struct negation; // C++17
421 inline constexpr bool negation_v = negation<B>::value; // C++17
428 #include <__type_traits/add_cv_quals.h>
429 #include <__type_traits/add_lvalue_reference.h>
430 #include <__type_traits/add_pointer.h>
431 #include <__type_traits/add_rvalue_reference.h>
432 #include <__type_traits/aligned_storage.h>
433 #include <__type_traits/aligned_union.h>
434 #include <__type_traits/alignment_of.h>
435 #include <__type_traits/common_type.h>
436 #include <__type_traits/conditional.h>
437 #include <__type_traits/decay.h>
438 #include <__type_traits/enable_if.h>
439 #include <__type_traits/extent.h>
440 #include <__type_traits/has_virtual_destructor.h>
441 #include <__type_traits/integral_constant.h>
442 #include <__type_traits/is_abstract.h>
443 #include <__type_traits/is_arithmetic.h>
444 #include <__type_traits/is_array.h>
445 #include <__type_traits/is_assignable.h>
446 #include <__type_traits/is_base_of.h>
447 #include <__type_traits/is_class.h>
448 #include <__type_traits/is_compound.h>
449 #include <__type_traits/is_const.h>
450 #include <__type_traits/is_constructible.h>
451 #include <__type_traits/is_convertible.h>
452 #include <__type_traits/is_destructible.h>
453 #include <__type_traits/is_empty.h>
454 #include <__type_traits/is_enum.h>
455 #include <__type_traits/is_floating_point.h>
456 #include <__type_traits/is_function.h>
457 #include <__type_traits/is_fundamental.h>
458 #include <__type_traits/is_integral.h>
459 #include <__type_traits/is_literal_type.h>
460 #include <__type_traits/is_member_pointer.h>
461 #include <__type_traits/is_nothrow_assignable.h>
462 #include <__type_traits/is_nothrow_constructible.h>
463 #include <__type_traits/is_nothrow_destructible.h>
464 #include <__type_traits/is_object.h>
465 #include <__type_traits/is_pod.h>
466 #include <__type_traits/is_pointer.h>
467 #include <__type_traits/is_polymorphic.h>
468 #include <__type_traits/is_reference.h>
469 #include <__type_traits/is_same.h>
470 #include <__type_traits/is_scalar.h>
471 #include <__type_traits/is_signed.h>
472 #include <__type_traits/is_standard_layout.h>
473 #include <__type_traits/is_trivial.h>
474 #include <__type_traits/is_trivially_assignable.h>
475 #include <__type_traits/is_trivially_constructible.h>
476 #include <__type_traits/is_trivially_copyable.h>
477 #include <__type_traits/is_trivially_destructible.h>
478 #include <__type_traits/is_union.h>
479 #include <__type_traits/is_unsigned.h>
480 #include <__type_traits/is_void.h>
481 #include <__type_traits/is_volatile.h>
482 #include <__type_traits/make_signed.h>
483 #include <__type_traits/make_unsigned.h>
484 #include <__type_traits/rank.h>
485 #include <__type_traits/remove_all_extents.h>
486 #include <__type_traits/remove_const.h>
487 #include <__type_traits/remove_cv.h>
488 #include <__type_traits/remove_extent.h>
489 #include <__type_traits/remove_pointer.h>
490 #include <__type_traits/remove_reference.h>
491 #include <__type_traits/remove_volatile.h>
492 #include <__type_traits/result_of.h>
493 #include <__type_traits/underlying_type.h>
495 #if _LIBCPP_STD_VER >= 14
496 # include <__type_traits/is_final.h>
497 # include <__type_traits/is_null_pointer.h>
500 #if _LIBCPP_STD_VER >= 17
501 # include <__type_traits/conjunction.h>
502 # include <__type_traits/disjunction.h>
503 # include <__type_traits/has_unique_object_representation.h>
504 # include <__type_traits/invoke.h>
505 # include <__type_traits/is_aggregate.h>
506 # include <__type_traits/is_swappable.h>
507 # include <__type_traits/negation.h>
508 # include <__type_traits/void_t.h>
511 #if _LIBCPP_STD_VER >= 20
512 # include <__type_traits/common_reference.h>
513 # include <__type_traits/is_bounded_array.h>
514 # include <__type_traits/is_constant_evaluated.h>
515 # include <__type_traits/is_nothrow_convertible.h>
516 # include <__type_traits/is_unbounded_array.h>
517 # include <__type_traits/type_identity.h>
518 # include <__type_traits/unwrap_ref.h>
521 #if _LIBCPP_STD_VER >= 23
522 # include <__type_traits/is_implicit_lifetime.h>
527 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
528 # pragma GCC system_header
531 #endif // _LIBCPP_TYPE_TRAITS