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The C and C++ Include Header Files
cat -n /usr/include/c++/15/tr1/type_traits
1 // TR1 type_traits -*- C++ -*- 2 3 // Copyright (C) 2004-2025 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 /** @file tr1/type_traits 26 * This is a TR1 C++ Library header. 27 */ 28 29 #ifndef _GLIBCXX_TR1_TYPE_TRAITS 30 #define _GLIBCXX_TR1_TYPE_TRAITS 1 31 32 #ifdef _GLIBCXX_SYSHDR 33 #pragma GCC system_header 34 #endif 35 36 #pragma GCC diagnostic push 37 #pragma GCC diagnostic ignored "-Wc++11-extensions" 38 39 #include <bits/requires_hosted.h> // TR1 40 41 #include <bits/c++config.h> 42 43 namespace std _GLIBCXX_VISIBILITY(default) 44 { 45 _GLIBCXX_BEGIN_NAMESPACE_VERSION 46 47 namespace tr1 48 { 49 /** 50 * @addtogroup metaprogramming 51 * @{ 52 */ 53 54 struct __sfinae_types 55 { 56 typedef char __one; 57 typedef struct { char __arr[2]; } __two; 58 }; 59 60 #define _DEFINE_SPEC_0_HELPER \ 61 template<> 62 63 #define _DEFINE_SPEC_1_HELPER \ 64 template<typename _Tp> 65 66 #define _DEFINE_SPEC_2_HELPER \ 67 template<typename _Tp, typename _Cp> 68 69 #define _DEFINE_SPEC(_Order, _Trait, _Type, _Value) \ 70 _DEFINE_SPEC_##_Order##_HELPER \ 71 struct _Trait<_Type> \ 72 : public integral_constant<bool, _Value> { }; 73 74 // helper classes [4.3]. 75 76 /// integral_constant 77 template<typename _Tp, _Tp __v> 78 struct integral_constant 79 { 80 static const _Tp value = __v; 81 typedef _Tp value_type; 82 typedef integral_constant<_Tp, __v> type; 83 }; 84 85 /// typedef for true_type 86 typedef integral_constant<bool, true> true_type; 87 88 /// typedef for false_type 89 typedef integral_constant<bool, false> false_type; 90 91 template<typename _Tp, _Tp __v> 92 const _Tp integral_constant<_Tp, __v>::value; 93 94 /// remove_cv 95 template<typename> 96 struct remove_cv; 97 98 template<typename> 99 struct __is_void_helper 100 : public false_type { }; 101 _DEFINE_SPEC(0, __is_void_helper, void, true) 102 103 // primary type categories [4.5.1]. 104 105 /// is_void 106 template<typename _Tp> 107 struct is_void 108 : public integral_constant<bool, (__is_void_helper<typename 109 remove_cv<_Tp>::type>::value)> 110 { }; 111 112 template<typename> 113 struct __is_integral_helper 114 : public false_type { }; 115 _DEFINE_SPEC(0, __is_integral_helper, bool, true) 116 _DEFINE_SPEC(0, __is_integral_helper, char, true) 117 _DEFINE_SPEC(0, __is_integral_helper, signed char, true) 118 _DEFINE_SPEC(0, __is_integral_helper, unsigned char, true) 119 _DEFINE_SPEC(0, __is_integral_helper, wchar_t, true) 120 _DEFINE_SPEC(0, __is_integral_helper, short, true) 121 _DEFINE_SPEC(0, __is_integral_helper, unsigned short, true) 122 _DEFINE_SPEC(0, __is_integral_helper, int, true) 123 _DEFINE_SPEC(0, __is_integral_helper, unsigned int, true) 124 _DEFINE_SPEC(0, __is_integral_helper, long, true) 125 _DEFINE_SPEC(0, __is_integral_helper, unsigned long, true) 126 #pragma GCC diagnostic push 127 #pragma GCC diagnostic ignored "-Wlong-long" 128 _DEFINE_SPEC(0, __is_integral_helper, long long, true) 129 _DEFINE_SPEC(0, __is_integral_helper, unsigned long long, true) 130 #pragma GCC diagnostic pop 131 132 /// is_integral 133 template<typename _Tp> 134 struct is_integral 135 : public integral_constant<bool, (__is_integral_helper<typename 136 remove_cv<_Tp>::type>::value)> 137 { }; 138 139 template<typename> 140 struct __is_floating_point_helper 141 : public false_type { }; 142 _DEFINE_SPEC(0, __is_floating_point_helper, float, true) 143 _DEFINE_SPEC(0, __is_floating_point_helper, double, true) 144 _DEFINE_SPEC(0, __is_floating_point_helper, long double, true) 145 146 /// is_floating_point 147 template<typename _Tp> 148 struct is_floating_point 149 : public integral_constant<bool, (__is_floating_point_helper<typename 150 remove_cv<_Tp>::type>::value)> 151 { }; 152 153 /// is_array 154 template<typename> 155 struct is_array 156 : public false_type { }; 157 158 template<typename _Tp, std::size_t _Size> 159 struct is_array<_Tp[_Size]> 160 : public true_type { }; 161 162 template<typename _Tp> 163 struct is_array<_Tp[]> 164 : public true_type { }; 165 166 template<typename> 167 struct __is_pointer_helper 168 : public false_type { }; 169 _DEFINE_SPEC(1, __is_pointer_helper, _Tp*, true) 170 171 /// is_pointer 172 template<typename _Tp> 173 struct is_pointer 174 : public integral_constant<bool, (__is_pointer_helper<typename 175 remove_cv<_Tp>::type>::value)> 176 { }; 177 178 /// is_reference 179 template<typename _Tp> 180 struct is_reference; 181 182 /// is_function 183 template<typename _Tp> 184 struct is_function; 185 186 template<typename> 187 struct __is_member_object_pointer_helper 188 : public false_type { }; 189 _DEFINE_SPEC(2, __is_member_object_pointer_helper, _Tp _Cp::*, 190 !is_function<_Tp>::value) 191 192 /// is_member_object_pointer 193 template<typename _Tp> 194 struct is_member_object_pointer 195 : public integral_constant<bool, (__is_member_object_pointer_helper< 196 typename remove_cv<_Tp>::type>::value)> 197 { }; 198 199 template<typename> 200 struct __is_member_function_pointer_helper 201 : public false_type { }; 202 _DEFINE_SPEC(2, __is_member_function_pointer_helper, _Tp _Cp::*, 203 is_function<_Tp>::value) 204 205 /// is_member_function_pointer 206 template<typename _Tp> 207 struct is_member_function_pointer 208 : public integral_constant<bool, (__is_member_function_pointer_helper< 209 typename remove_cv<_Tp>::type>::value)> 210 { }; 211 212 /// is_enum 213 template<typename _Tp> 214 struct is_enum 215 : public integral_constant<bool, __is_enum(_Tp)> 216 { }; 217 218 /// is_union 219 template<typename _Tp> 220 struct is_union 221 : public integral_constant<bool, __is_union(_Tp)> 222 { }; 223 224 /// is_class 225 template<typename _Tp> 226 struct is_class 227 : public integral_constant<bool, __is_class(_Tp)> 228 { }; 229 230 /// is_function 231 template<typename> 232 struct is_function 233 : public false_type { }; 234 template<typename _Res, typename... _ArgTypes> 235 struct is_function<_Res(_ArgTypes...)> 236 : public true_type { }; 237 template<typename _Res, typename... _ArgTypes> 238 struct is_function<_Res(_ArgTypes..., ...)> : public true_type { }; 239 template<typename _Res, typename... _ArgTypes> 240 struct is_function<_Res(_ArgTypes...) const> 241 : public true_type { }; 242 template<typename _Res, typename... _ArgTypes> 243 struct is_function<_Res(_ArgTypes..., ...) const> 244 : public true_type { }; 245 template<typename _Res, typename... _ArgTypes> 246 struct is_function<_Res(_ArgTypes...) volatile> 247 : public true_type { }; 248 template<typename _Res, typename... _ArgTypes> 249 struct is_function<_Res(_ArgTypes..., ...) volatile> 250 : public true_type { }; 251 template<typename _Res, typename... _ArgTypes> 252 struct is_function<_Res(_ArgTypes...) const volatile> 253 : public true_type { }; 254 template<typename _Res, typename... _ArgTypes> 255 struct is_function<_Res(_ArgTypes..., ...) const volatile> 256 : public true_type { }; 257 258 // composite type traits [4.5.2]. 259 260 /// is_arithmetic 261 template<typename _Tp> 262 struct is_arithmetic 263 : public integral_constant<bool, (is_integral<_Tp>::value 264 || is_floating_point<_Tp>::value)> 265 { }; 266 267 /// is_fundamental 268 template<typename _Tp> 269 struct is_fundamental 270 : public integral_constant<bool, (is_arithmetic<_Tp>::value 271 || is_void<_Tp>::value)> 272 { }; 273 274 /// is_object 275 template<typename _Tp> 276 struct is_object 277 : public integral_constant<bool, !(is_function<_Tp>::value 278 || is_reference<_Tp>::value 279 || is_void<_Tp>::value)> 280 { }; 281 282 /// is_member_pointer 283 template<typename _Tp> 284 struct is_member_pointer; 285 286 /// is_scalar 287 template<typename _Tp> 288 struct is_scalar 289 : public integral_constant<bool, (is_arithmetic<_Tp>::value 290 || is_enum<_Tp>::value 291 || is_pointer<_Tp>::value 292 || is_member_pointer<_Tp>::value)> 293 { }; 294 295 /// is_compound 296 template<typename _Tp> 297 struct is_compound 298 : public integral_constant<bool, !is_fundamental<_Tp>::value> { }; 299 300 /// is_member_pointer 301 template<typename _Tp> 302 struct __is_member_pointer_helper 303 : public false_type { }; 304 _DEFINE_SPEC(2, __is_member_pointer_helper, _Tp _Cp::*, true) 305 306 template<typename _Tp> 307 struct is_member_pointer 308 : public integral_constant<bool, (__is_member_pointer_helper< 309 typename remove_cv<_Tp>::type>::value)> 310 { }; 311 312 // type properties [4.5.3]. 313 /// is_const 314 template<typename> 315 struct is_const 316 : public false_type { }; 317 318 template<typename _Tp> 319 struct is_const<_Tp const> 320 : public true_type { }; 321 322 /// is_volatile 323 template<typename> 324 struct is_volatile 325 : public false_type { }; 326 327 template<typename _Tp> 328 struct is_volatile<_Tp volatile> 329 : public true_type { }; 330 331 /// is_empty 332 template<typename _Tp> 333 struct is_empty 334 : public integral_constant<bool, __is_empty(_Tp)> 335 { }; 336 337 /// is_polymorphic 338 template<typename _Tp> 339 struct is_polymorphic 340 : public integral_constant<bool, __is_polymorphic(_Tp)> 341 { }; 342 343 /// is_abstract 344 template<typename _Tp> 345 struct is_abstract 346 : public integral_constant<bool, __is_abstract(_Tp)> 347 { }; 348 349 /// has_virtual_destructor 350 template<typename _Tp> 351 struct has_virtual_destructor 352 : public integral_constant<bool, __has_virtual_destructor(_Tp)> 353 { }; 354 355 /// alignment_of 356 template<typename _Tp> 357 struct alignment_of 358 : public integral_constant<std::size_t, __alignof__(_Tp)> { }; 359 360 /// rank 361 template<typename> 362 struct rank 363 : public integral_constant<std::size_t, 0> { }; 364 365 template<typename _Tp, std::size_t _Size> 366 struct rank<_Tp[_Size]> 367 : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { }; 368 369 template<typename _Tp> 370 struct rank<_Tp[]> 371 : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { }; 372 373 /// extent 374 template<typename, unsigned _Uint = 0> 375 struct extent 376 : public integral_constant<std::size_t, 0> { }; 377 378 template<typename _Tp, unsigned _Uint, std::size_t _Size> 379 struct extent<_Tp[_Size], _Uint> 380 : public integral_constant<std::size_t, 381 _Uint == 0 ? _Size : extent<_Tp, 382 _Uint - 1>::value> 383 { }; 384 385 template<typename _Tp, unsigned _Uint> 386 struct extent<_Tp[], _Uint> 387 : public integral_constant<std::size_t, 388 _Uint == 0 ? 0 : extent<_Tp, 389 _Uint - 1>::value> 390 { }; 391 392 // relationships between types [4.6]. 393 394 /// is_same 395 template<typename, typename> 396 struct is_same 397 : public false_type { }; 398 399 template<typename _Tp> 400 struct is_same<_Tp, _Tp> 401 : public true_type { }; 402 403 // const-volatile modifications [4.7.1]. 404 405 /// remove_const 406 template<typename _Tp> 407 struct remove_const 408 { typedef _Tp type; }; 409 410 template<typename _Tp> 411 struct remove_const<_Tp const> 412 { typedef _Tp type; }; 413 414 /// remove_volatile 415 template<typename _Tp> 416 struct remove_volatile 417 { typedef _Tp type; }; 418 419 template<typename _Tp> 420 struct remove_volatile<_Tp volatile> 421 { typedef _Tp type; }; 422 423 /// remove_cv 424 template<typename _Tp> 425 struct remove_cv 426 { 427 typedef typename 428 remove_const<typename remove_volatile<_Tp>::type>::type type; 429 }; 430 431 /// add_const 432 template<typename _Tp> 433 struct add_const 434 { typedef _Tp const type; }; 435 436 /// add_volatile 437 template<typename _Tp> 438 struct add_volatile 439 { typedef _Tp volatile type; }; 440 441 /// add_cv 442 template<typename _Tp> 443 struct add_cv 444 { 445 typedef typename 446 add_const<typename add_volatile<_Tp>::type>::type type; 447 }; 448 449 // array modifications [4.7.3]. 450 451 /// remove_extent 452 template<typename _Tp> 453 struct remove_extent 454 { typedef _Tp type; }; 455 456 template<typename _Tp, std::size_t _Size> 457 struct remove_extent<_Tp[_Size]> 458 { typedef _Tp type; }; 459 460 template<typename _Tp> 461 struct remove_extent<_Tp[]> 462 { typedef _Tp type; }; 463 464 /// remove_all_extents 465 template<typename _Tp> 466 struct remove_all_extents 467 { typedef _Tp type; }; 468 469 template<typename _Tp, std::size_t _Size> 470 struct remove_all_extents<_Tp[_Size]> 471 { typedef typename remove_all_extents<_Tp>::type type; }; 472 473 template<typename _Tp> 474 struct remove_all_extents<_Tp[]> 475 { typedef typename remove_all_extents<_Tp>::type type; }; 476 477 // pointer modifications [4.7.4]. 478 479 template<typename _Tp, typename> 480 struct __remove_pointer_helper 481 { typedef _Tp type; }; 482 483 template<typename _Tp, typename _Up> 484 struct __remove_pointer_helper<_Tp, _Up*> 485 { typedef _Up type; }; 486 487 /// remove_pointer 488 template<typename _Tp> 489 struct remove_pointer 490 : public __remove_pointer_helper<_Tp, typename remove_cv<_Tp>::type> 491 { }; 492 493 template<typename> 494 struct remove_reference; 495 496 /// add_pointer 497 template<typename _Tp> 498 struct add_pointer 499 { typedef typename remove_reference<_Tp>::type* type; }; 500 501 template<typename> 502 struct is_reference 503 : public false_type { }; 504 505 template<typename _Tp> 506 struct is_reference<_Tp&> 507 : public true_type { }; 508 509 template<typename _Tp> 510 struct is_pod 511 : public integral_constant<bool, __is_pod(_Tp) || is_void<_Tp>::value> 512 { }; 513 514 template<typename _Tp> 515 struct has_trivial_constructor 516 : public integral_constant<bool, is_pod<_Tp>::value> 517 { }; 518 519 template<typename _Tp> 520 struct has_trivial_copy 521 : public integral_constant<bool, is_pod<_Tp>::value> 522 { }; 523 524 template<typename _Tp> 525 struct has_trivial_assign 526 : public integral_constant<bool, is_pod<_Tp>::value> 527 { }; 528 529 template<typename _Tp> 530 struct has_trivial_destructor 531 : public integral_constant<bool, is_pod<_Tp>::value> 532 { }; 533 534 template<typename _Tp> 535 struct has_nothrow_constructor 536 : public integral_constant<bool, is_pod<_Tp>::value> 537 { }; 538 539 template<typename _Tp> 540 struct has_nothrow_copy 541 : public integral_constant<bool, is_pod<_Tp>::value> 542 { }; 543 544 template<typename _Tp> 545 struct has_nothrow_assign 546 : public integral_constant<bool, is_pod<_Tp>::value> 547 { }; 548 549 #pragma GCC diagnostic push 550 #pragma GCC diagnostic ignored "-Wlong-long" 551 template<typename> 552 struct __is_signed_helper 553 : public false_type { }; 554 _DEFINE_SPEC(0, __is_signed_helper, signed char, true) 555 _DEFINE_SPEC(0, __is_signed_helper, short, true) 556 _DEFINE_SPEC(0, __is_signed_helper, int, true) 557 _DEFINE_SPEC(0, __is_signed_helper, long, true) 558 _DEFINE_SPEC(0, __is_signed_helper, long long, true) 559 560 template<typename _Tp> 561 struct is_signed 562 : public integral_constant<bool, (__is_signed_helper<typename 563 remove_cv<_Tp>::type>::value)> 564 { }; 565 566 template<typename> 567 struct __is_unsigned_helper 568 : public false_type { }; 569 _DEFINE_SPEC(0, __is_unsigned_helper, unsigned char, true) 570 _DEFINE_SPEC(0, __is_unsigned_helper, unsigned short, true) 571 _DEFINE_SPEC(0, __is_unsigned_helper, unsigned int, true) 572 _DEFINE_SPEC(0, __is_unsigned_helper, unsigned long, true) 573 _DEFINE_SPEC(0, __is_unsigned_helper, unsigned long long, true) 574 #pragma GCC diagnostic pop 575 576 template<typename _Tp> 577 struct is_unsigned 578 : public integral_constant<bool, (__is_unsigned_helper<typename 579 remove_cv<_Tp>::type>::value)> 580 { }; 581 582 template<typename _Base, typename _Derived> 583 struct __is_base_of_helper 584 { 585 typedef typename remove_cv<_Base>::type _NoCv_Base; 586 typedef typename remove_cv<_Derived>::type _NoCv_Derived; 587 static const bool __value = (is_same<_Base, _Derived>::value 588 || (__is_base_of(_Base, _Derived) 589 && !is_same<_NoCv_Base, 590 _NoCv_Derived>::value)); 591 }; 592 593 template<typename _Base, typename _Derived> 594 struct is_base_of 595 : public integral_constant<bool, 596 __is_base_of_helper<_Base, _Derived>::__value> 597 { }; 598 599 template<typename _From, typename _To> 600 struct __is_convertible_simple 601 : public __sfinae_types 602 { 603 private: 604 static __one __test(_To); 605 static __two __test(...); 606 static _From __makeFrom(); 607 608 public: 609 static const bool __value = sizeof(__test(__makeFrom())) == 1; 610 }; 611 612 template<typename _Tp> 613 struct add_reference; 614 615 template<typename _Tp> 616 struct __is_int_or_cref 617 { 618 typedef typename remove_reference<_Tp>::type __rr_Tp; 619 static const bool __value = (is_integral<_Tp>::value 620 || (is_integral<__rr_Tp>::value 621 && is_const<__rr_Tp>::value 622 && !is_volatile<__rr_Tp>::value)); 623 }; 624 625 template<typename _From, typename _To, 626 bool = (is_void<_From>::value || is_void<_To>::value 627 || is_function<_To>::value || is_array<_To>::value 628 // This special case is here only to avoid warnings. 629 || (is_floating_point<typename 630 remove_reference<_From>::type>::value 631 && __is_int_or_cref<_To>::__value))> 632 struct __is_convertible_helper 633 { 634 // "An imaginary lvalue of type From...". 635 static const bool __value = (__is_convertible_simple<typename 636 add_reference<_From>::type, _To>::__value); 637 }; 638 639 template<typename _From, typename _To> 640 struct __is_convertible_helper<_From, _To, true> 641 { static const bool __value = (is_void<_To>::value 642 || (__is_int_or_cref<_To>::__value 643 && !is_void<_From>::value)); }; 644 645 template<typename _From, typename _To> 646 struct is_convertible 647 : public integral_constant<bool, 648 __is_convertible_helper<_From, _To>::__value> 649 { }; 650 651 // reference modifications [4.7.2]. 652 template<typename _Tp> 653 struct remove_reference 654 { typedef _Tp type; }; 655 656 template<typename _Tp> 657 struct remove_reference<_Tp&> 658 { typedef _Tp type; }; 659 660 // NB: Careful with reference to void. 661 template<typename _Tp, bool = (is_void<_Tp>::value 662 || is_reference<_Tp>::value)> 663 struct __add_reference_helper 664 { typedef _Tp& type; }; 665 666 template<typename _Tp> 667 struct __add_reference_helper<_Tp, true> 668 { typedef _Tp type; }; 669 670 template<typename _Tp> 671 struct add_reference 672 : public __add_reference_helper<_Tp> 673 { }; 674 675 // other transformations [4.8]. 676 template<std::size_t _Len, std::size_t _Align> 677 struct aligned_storage 678 { 679 union type 680 { 681 unsigned char __data[_Len]; 682 struct __attribute__((__aligned__((_Align)))) { } __align; 683 }; 684 }; 685 686 #undef _DEFINE_SPEC_0_HELPER 687 #undef _DEFINE_SPEC_1_HELPER 688 #undef _DEFINE_SPEC_2_HELPER 689 #undef _DEFINE_SPEC 690 691 /// @} group metaprogramming 692 } 693 694 _GLIBCXX_END_NAMESPACE_VERSION 695 } 696 697 #pragma GCC diagnostic pop 698 #endif // _GLIBCXX_TR1_TYPE_TRAITS
