libstdc++-v3/include/ext/typelist.h

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005-2014 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 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
  26
  27 // Permission to use, copy, modify, sell, and distribute this software
  28 // is hereby granted without fee, provided that the above copyright
  29 // notice appears in all copies, and that both that copyright notice and
  30 // this permission notice appear in supporting documentation. None of
  31 // the above authors, nor IBM Haifa Research Laboratories, make any
  32 // representation about the suitability of this software for any
  33 // purpose. It is provided "as is" without express or implied warranty.
  34
  35 /**
  36  *  @file ext/typelist.h
  37  *  This file is a GNU extension to the Standard C++ Library.
  38  *
  39  *  Contains typelist_chain definitions.
  40  *  Typelists are an idea by Andrei Alexandrescu.
  41  */
  42
  43 #ifndef _TYPELIST_H
  44 #define _TYPELIST_H 1
  45
  46 #include <ext/type_traits.h>
  47
  48 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
  49 {
  50 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  51
  52 /** @namespace __gnu_cxx::typelist
  53  *  @brief GNU typelist extensions for public compile-time use.
  54 */
  55 namespace typelist
  56 {
  57   struct null_type { };
  58
  59   template<typename Root>
  60     struct node
  61     {
  62       typedef Root      root;
  63     };
  64
  65   // Forward declarations of functors.
  66   template<typename Hd, typename Typelist>
  67     struct chain
  68     {
  69       typedef Hd        head;
  70       typedef Typelist  tail;
  71     };
  72
  73   // Apply all typelist types to unary functor.
  74   template<typename Fn, typename Typelist>
  75     void
  76     apply(Fn&, Typelist);
  77
  78   /// Apply all typelist types to generator functor.
  79   template<typename Gn, typename Typelist>
  80     void
  81     apply_generator(Gn&, Typelist);
  82
  83   // Apply all typelist types and values to generator functor.
  84   template<typename Gn, typename TypelistT, typename TypelistV>
  85     void
  86     apply_generator(Gn&, TypelistT, TypelistV);
  87
  88   template<typename Typelist0, typename Typelist1>
  89     struct append;
  90
  91   template<typename Typelist_Typelist>
  92     struct append_typelist;
  93
  94   template<typename Typelist, typename T>
  95     struct contains;
  96
  97   template<typename Typelist, template<typename T> class Pred>
  98     struct filter;
  99
 100   template<typename Typelist, int i>
 101     struct at_index;
 102
 103   template<typename Typelist, template<typename T> class Transform>
 104     struct transform;
 105
 106   template<typename Typelist_Typelist>
 107     struct flatten;
 108
 109   template<typename Typelist>
 110     struct from_first;
 111
 112   template<typename T1>
 113     struct create1;
 114
 115   template<typename T1, typename T2>
 116     struct create2;
 117
 118   template<typename T1, typename T2, typename T3>
 119     struct create3;
 120
 121   template<typename T1, typename T2, typename T3, typename T4>
 122     struct create4;
 123
 124   template<typename T1, typename T2, typename T3, typename T4, typename T5>
 125     struct create5;
 126
 127   template<typename T1, typename T2, typename T3,
 128            typename T4, typename T5, typename T6>
 129     struct create6;
 130 } // namespace typelist
 131
 132 _GLIBCXX_END_NAMESPACE_VERSION
 133 } // namespace
 134
 135
 136 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
 137 {
 138 _GLIBCXX_BEGIN_NAMESPACE_VERSION
 139
 140 namespace typelist
 141 {
 142 namespace detail
 143 {
 144   template<typename Fn, typename Typelist_Chain>
 145     struct apply_;
 146
 147   template<typename Fn, typename Hd, typename Tl>
 148     struct apply_<Fn, chain<Hd, Tl> >
 149     {
 150       void
 151       operator()(Fn& f)
 152       {
 153         f.operator()(Hd());
 154         apply_<Fn, Tl> next;
 155         next(f);
 156       }
 157     };
 158
 159   template<typename Fn>
 160     struct apply_<Fn, null_type>
 161     {
 162       void
 163       operator()(Fn&) { }
 164     };
 165
 166   template<typename Gn, typename Typelist_Chain>
 167     struct apply_generator1_;
 168
 169   template<typename Gn, typename Hd, typename Tl>
 170     struct apply_generator1_<Gn, chain<Hd, Tl> >
 171     {
 172       void
 173       operator()(Gn& g)
 174       {
 175         g.template operator()<Hd>();
 176         apply_generator1_<Gn, Tl> next;
 177         next(g);
 178       }
 179     };
 180
 181   template<typename Gn>
 182     struct apply_generator1_<Gn, null_type>
 183     {
 184       void
 185       operator()(Gn&) { }
 186     };
 187
 188   template<typename Gn, typename TypelistT_Chain, typename TypelistV_Chain>
 189     struct apply_generator2_;
 190
 191   template<typename Gn, typename Hd1, typename TlT, typename Hd2, typename TlV>
 192     struct apply_generator2_<Gn, chain<Hd1, TlT>, chain<Hd2, TlV> >
 193     {
 194       void
 195       operator()(Gn& g)
 196       {
 197         g.template operator()<Hd1, Hd2>();
 198         apply_generator2_<Gn, TlT, TlV> next;
 199         next(g);
 200       }
 201     };
 202
 203   template<typename Gn>
 204     struct apply_generator2_<Gn, null_type, null_type>
 205     {
 206       void
 207       operator()(Gn&) { }
 208     };
 209
 210   template<typename Typelist_Chain0, typename Typelist_Chain1>
 211     struct append_;
 212
 213   template<typename Hd, typename Tl, typename Typelist_Chain>
 214     struct append_<chain<Hd, Tl>, Typelist_Chain>
 215     {
 216     private:
 217       typedef append_<Tl, Typelist_Chain>                       append_type;
 218
 219     public:
 220       typedef chain<Hd, typename append_type::type>             type;
 221     };
 222
 223   template<typename Typelist_Chain>
 224     struct append_<null_type, Typelist_Chain>
 225     {
 226       typedef Typelist_Chain                                    type;
 227     };
 228
 229   template<typename Typelist_Chain>
 230     struct append_<Typelist_Chain, null_type>
 231     {
 232       typedef Typelist_Chain                                    type;
 233     };
 234
 235   template<>
 236     struct append_<null_type, null_type>
 237     {
 238       typedef null_type                                         type;
 239     };
 240
 241   template<typename Typelist_Typelist_Chain>
 242     struct append_typelist_;
 243
 244   template<typename Hd>
 245     struct append_typelist_<chain<Hd, null_type> >
 246     {
 247       typedef chain<Hd, null_type>                              type;
 248     };
 249
 250   template<typename Hd, typename Tl>
 251     struct append_typelist_<chain< Hd, Tl> >
 252     {
 253     private:
 254       typedef typename append_typelist_<Tl>::type               rest_type;
 255
 256     public:
 257       typedef typename append<Hd, node<rest_type> >::type::root type;
 258     };
 259
 260   template<typename Typelist_Chain, typename T>
 261     struct contains_;
 262
 263   template<typename T>
 264     struct contains_<null_type, T>
 265     {
 266       enum
 267         {
 268           value = false
 269         };
 270     };
 271
 272   template<typename Hd, typename Tl, typename T>
 273     struct contains_<chain<Hd, Tl>, T>
 274     {
 275       enum
 276         {
 277           value = contains_<Tl, T>::value
 278         };
 279     };
 280
 281   template<typename Tl, typename T>
 282     struct contains_<chain<T, Tl>, T>
 283     {
 284       enum
 285         {
 286           value = true
 287         };
 288     };
 289
 290   template<typename Typelist_Chain, template<typename T> class Pred>
 291     struct chain_filter_;
 292
 293   template<template<typename T> class Pred>
 294     struct chain_filter_<null_type, Pred>
 295     {
 296       typedef null_type                                         type;
 297   };
 298
 299   template<typename Hd, typename Tl, template<typename T> class Pred>
 300     struct chain_filter_<chain<Hd, Tl>, Pred>
 301     {
 302     private:
 303       enum
 304         {
 305           include_hd = Pred<Hd>::value
 306         };
 307
 308       typedef typename chain_filter_<Tl, Pred>::type            rest_type;
 309       typedef chain<Hd, rest_type>                              chain_type;
 310
 311     public:
 312       typedef typename __conditional_type<include_hd, chain_type, rest_type>::__type type;
 313   };
 314
 315   template<typename Typelist_Chain, int i>
 316     struct chain_at_index_;
 317
 318   template<typename Hd, typename Tl>
 319     struct chain_at_index_<chain<Hd, Tl>, 0>
 320     {
 321       typedef Hd                                                type;
 322     };
 323
 324   template<typename Hd, typename Tl, int i>
 325     struct chain_at_index_<chain<Hd, Tl>, i>
 326     {
 327       typedef typename chain_at_index_<Tl, i - 1>::type         type;
 328     };
 329
 330   template<class Typelist_Chain, template<typename T> class Transform>
 331     struct chain_transform_;
 332
 333   template<template<typename T> class Transform>
 334     struct chain_transform_<null_type, Transform>
 335     {
 336       typedef null_type                                         type;
 337     };
 338
 339   template<class Hd, class Tl, template<typename T> class Transform>
 340     struct chain_transform_<chain<Hd, Tl>, Transform>
 341     {
 342     private:
 343       typedef typename chain_transform_<Tl, Transform>::type    rest_type;
 344       typedef typename Transform<Hd>::type                      transform_type;
 345
 346     public:
 347       typedef chain<transform_type, rest_type>                  type;
 348     };
 349
 350   template<typename Typelist_Typelist_Chain>
 351     struct chain_flatten_;
 352
 353   template<typename Hd_Tl>
 354     struct chain_flatten_<chain<Hd_Tl, null_type> >
 355     {
 356       typedef typename Hd_Tl::root                              type;
 357     };
 358
 359   template<typename Hd_Typelist, class Tl_Typelist>
 360     struct chain_flatten_<chain<Hd_Typelist, Tl_Typelist> >
 361     {
 362     private:
 363       typedef typename chain_flatten_<Tl_Typelist>::type        rest_type;
 364       typedef append<Hd_Typelist, node<rest_type> >             append_type;
 365     public:
 366       typedef typename append_type::type::root                  type;
 367     };
 368 } // namespace detail
 369 } // namespace typelist
 370
 371 _GLIBCXX_END_NAMESPACE_VERSION
 372 } // namespace
 373
 374 #define _GLIBCXX_TYPELIST_CHAIN1(X0) __gnu_cxx::typelist::chain<X0, __gnu_cxx::typelist::null_type>
 375 #define _GLIBCXX_TYPELIST_CHAIN2(X0, X1) __gnu_cxx::typelist::chain<X0, _GLIBCXX_TYPELIST_CHAIN1(X1) >
 376 #define _GLIBCXX_TYPELIST_CHAIN3(X0, X1, X2) __gnu_cxx::typelist::chain<X0, _GLIBCXX_TYPELIST_CHAIN2(X1, X2) >
 377 #define _GLIBCXX_TYPELIST_CHAIN4(X0, X1, X2, X3) __gnu_cxx::typelist::chain<X0, _GLIBCXX_TYPELIST_CHAIN3(X1, X2, X3) >
 378 #define _GLIBCXX_TYPELIST_CHAIN5(X0, X1, X2, X3, X4) __gnu_cxx::typelist::chain<X0, _GLIBCXX_TYPELIST_CHAIN4(X1, X2, X3, X4) >
 379 #define _GLIBCXX_TYPELIST_CHAIN6(X0, X1, X2, X3, X4, X5) __gnu_cxx::typelist::chain<X0, _GLIBCXX_TYPELIST_CHAIN5(X1, X2, X3, X4, X5) >
 380 #define _GLIBCXX_TYPELIST_CHAIN7(X0, X1, X2, X3, X4, X5, X6) __gnu_cxx::typelist::chain<X0, _GLIBCXX_TYPELIST_CHAIN6(X1, X2, X3, X4, X5, X6) >
 381 #define _GLIBCXX_TYPELIST_CHAIN8(X0, X1, X2, X3, X4, X5, X6, X7) __gnu_cxx::typelist::chain<X0, _GLIBCXX_TYPELIST_CHAIN7(X1, X2, X3, X4, X5, X6, X7) >
 382 #define _GLIBCXX_TYPELIST_CHAIN9(X0, X1, X2, X3, X4, X5, X6, X7, X8) __gnu_cxx::typelist::chain<X0, _GLIBCXX_TYPELIST_CHAIN8(X1, X2, X3, X4, X5, X6, X7, X8) >
 383 #define _GLIBCXX_TYPELIST_CHAIN10(X0, X1, X2, X3, X4, X5, X6, X7, X8, X9) __gnu_cxx::typelist::chain<X0, _GLIBCXX_TYPELIST_CHAIN9(X1, X2, X3, X4, X5, X6, X7, X8, X9) >
 384 #define _GLIBCXX_TYPELIST_CHAIN11(X0, X1, X2, X3, X4, X5, X6, X7, X8, X9, X10) __gnu_cxx::typelist::chain<X0, _GLIBCXX_TYPELIST_CHAIN10(X1, X2, X3, X4, X5, X6, X7, X8, X9, X10) >
 385 #define _GLIBCXX_TYPELIST_CHAIN12(X0, X1, X2, X3, X4, X5, X6, X7, X8, X9, X10, X11) __gnu_cxx::typelist::chain<X0, _GLIBCXX_TYPELIST_CHAIN11(X1, X2, X3, X4, X5, X6, X7, X8, X9, X10, X11) >
 386 #define _GLIBCXX_TYPELIST_CHAIN13(X0, X1, X2, X3, X4, X5, X6, X7, X8, X9, X10, X11, X12) __gnu_cxx::typelist::chain<X0, _GLIBCXX_TYPELIST_CHAIN12(X1, X2, X3, X4, X5, X6, X7, X8, X9, X10, X11, X12) >
 387 #define _GLIBCXX_TYPELIST_CHAIN14(X0, X1, X2, X3, X4, X5, X6, X7, X8, X9, X10, X11, X12, X13) __gnu_cxx::typelist::chain<X0, _GLIBCXX_TYPELIST_CHAIN13(X1, X2, X3, X4, X5, X6, X7, X8, X9, X10, X11, X12, X13) >
 388 #define _GLIBCXX_TYPELIST_CHAIN15(X0, X1, X2, X3, X4, X5, X6, X7, X8, X9, X10, X11, X12, X13, X14) __gnu_cxx::typelist::chain<X0, _GLIBCXX_TYPELIST_CHAIN14(X1, X2, X3, X4, X5, X6, X7, X8, X9, X10, X11, X12, X13, X14) >
 389 #define _GLIBCXX_TYPELIST_CHAIN16(X0, X1, X2, X3, X4, X5, X6, X7, X8, X9, X10, X11, X12, X13, X14, X15) __gnu_cxx::typelist::chain<X0, _GLIBCXX_TYPELIST_CHAIN15(X1, X2, X3, X4, X5, X6, X7, X8, X9, X10, X11, X12, X13, X14, X15) >
 390 #define _GLIBCXX_TYPELIST_CHAIN17(X0, X1, X2, X3, X4, X5, X6, X7, X8, X9, X10, X11, X12, X13, X14, X15, X16) __gnu_cxx::typelist::chain<X0, _GLIBCXX_TYPELIST_CHAIN16(X1, X2, X3, X4, X5, X6, X7, X8, X9, X10, X11, X12, X13, X14, X15, X16) >
 391 #define _GLIBCXX_TYPELIST_CHAIN18(X0, X1, X2, X3, X4, X5, X6, X7, X8, X9, X10, X11, X12, X13, X14, X15, X16, X17) __gnu_cxx::typelist::chain<X0, _GLIBCXX_TYPELIST_CHAIN17(X1, X2, X3, X4, X5, X6, X7, X8, X9, X10, X11, X12, X13, X14, X15, X16, X17) >
 392 #define _GLIBCXX_TYPELIST_CHAIN19(X0, X1, X2, X3, X4, X5, X6, X7, X8, X9, X10, X11, X12, X13, X14, X15, X16, X17, X18) __gnu_cxx::typelist::chain<X0, _GLIBCXX_TYPELIST_CHAIN18(X1, X2, X3, X4, X5, X6, X7, X8, X9, X10, X11, X12, X13, X14, X15, X16, X17, X18) >
 393 #define _GLIBCXX_TYPELIST_CHAIN20(X0, X1, X2, X3, X4, X5, X6, X7, X8, X9, X10, X11, X12, X13, X14, X15, X16, X17, X18, X19) __gnu_cxx::typelist::chain<X0, _GLIBCXX_TYPELIST_CHAIN19(X1, X2, X3, X4, X5, X6, X7, X8, X9, X10, X11, X12, X13, X14, X15, X16, X17, X18, X19) >
 394
 395 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
 396 {
 397 _GLIBCXX_BEGIN_NAMESPACE_VERSION
 398
 399 namespace typelist
 400 {
 401   template<typename Fn, typename Typelist>
 402     void
 403     apply(Fn& fn, Typelist)
 404     {
 405       detail::apply_<Fn, typename Typelist::root> a;
 406       a(fn);
 407     }
 408
 409   template<typename Fn, typename Typelist>
 410     void
 411     apply_generator(Fn& fn, Typelist)
 412     {
 413       detail::apply_generator1_<Fn, typename Typelist::root> a;
 414       a(fn);
 415     }
 416
 417   template<typename Fn, typename TypelistT, typename TypelistV>
 418     void
 419     apply_generator(Fn& fn, TypelistT, TypelistV)
 420     {
 421       typedef typename TypelistT::root rootT;
 422       typedef typename TypelistV::root rootV;
 423       detail::apply_generator2_<Fn, rootT, rootV> a;
 424       a(fn);
 425     }
 426
 427   template<typename Typelist0, typename Typelist1>
 428     struct append
 429     {
 430     private:
 431       typedef typename Typelist0::root                          root0_type;
 432       typedef typename Typelist1::root                          root1_type;
 433       typedef detail::append_<root0_type, root1_type>           append_type;
 434
 435     public:
 436       typedef node<typename append_type::type>                  type;
 437     };
 438
 439   template<typename Typelist_Typelist>
 440     struct append_typelist
 441     {
 442     private:
 443       typedef typename Typelist_Typelist::root                  root_type;
 444       typedef detail::append_typelist_<root_type>               append_type;
 445
 446     public:
 447       typedef node<typename append_type::type>                  type;
 448     };
 449
 450   template<typename Typelist, typename T>
 451     struct contains
 452     {
 453     private:
 454       typedef typename Typelist::root                           root_type;
 455
 456     public:
 457       enum
 458         {
 459           value = detail::contains_<root_type, T>::value
 460         };
 461     };
 462
 463   template<typename Typelist, template<typename T> class Pred>
 464     struct filter
 465     {
 466     private:
 467       typedef typename Typelist::root                           root_type;
 468       typedef detail::chain_filter_<root_type, Pred>            filter_type;
 469
 470     public:
 471       typedef node<typename filter_type::type>                  type;
 472     };
 473
 474   template<typename Typelist, int i>
 475     struct at_index
 476     {
 477     private:
 478       typedef typename Typelist::root                           root_type;
 479       typedef detail::chain_at_index_<root_type, i>             index_type;
 480
 481     public:
 482       typedef typename index_type::type                         type;
 483     };
 484
 485   template<typename Typelist, template<typename T> class Transform>
 486     struct transform
 487     {
 488     private:
 489       typedef typename Typelist::root                           root_type;
 490       typedef detail::chain_transform_<root_type, Transform>    transform_type;
 491
 492     public:
 493       typedef node<typename transform_type::type>               type;
 494     };
 495
 496   template<typename Typelist_Typelist>
 497     struct flatten
 498     {
 499     private:
 500       typedef typename Typelist_Typelist::root                  root_type;
 501       typedef typename detail::chain_flatten_<root_type>::type  flatten_type;
 502
 503     public:
 504       typedef node<flatten_type>                                type;
 505     };
 506
 507   template<typename Typelist>
 508     struct from_first
 509     {
 510     private:
 511       typedef typename at_index<Typelist, 0>::type              first_type;
 512
 513     public:
 514       typedef node<chain<first_type, null_type> >               type;
 515     };
 516
 517   template<typename T1>
 518     struct create1
 519     {
 520       typedef node<_GLIBCXX_TYPELIST_CHAIN1(T1)>                type;
 521     };
 522
 523   template<typename T1, typename T2>
 524     struct create2
 525     {
 526       typedef node<_GLIBCXX_TYPELIST_CHAIN2(T1,T2)>             type;
 527     };
 528
 529   template<typename T1, typename T2, typename T3>
 530     struct create3
 531     {
 532       typedef node<_GLIBCXX_TYPELIST_CHAIN3(T1,T2,T3)>          type;
 533     };
 534
 535   template<typename T1, typename T2, typename T3, typename T4>
 536     struct create4
 537     {
 538       typedef node<_GLIBCXX_TYPELIST_CHAIN4(T1,T2,T3,T4)>       type;
 539     };
 540
 541   template<typename T1, typename T2, typename T3,
 542            typename T4, typename T5>
 543     struct create5
 544     {
 545       typedef node<_GLIBCXX_TYPELIST_CHAIN5(T1,T2,T3,T4,T5)>    type;
 546     };
 547
 548   template<typename T1, typename T2, typename T3,
 549            typename T4, typename T5, typename T6>
 550     struct create6
 551     {
 552       typedef node<_GLIBCXX_TYPELIST_CHAIN6(T1,T2,T3,T4,T5,T6)> type;
 553     };
 554 } // namespace typelist
 555 _GLIBCXX_END_NAMESPACE_VERSION
 556 } // namespace
 557
 558
 559 #endif