libstdc++-v3/include/bits/stl_function.h

   1 // Functor implementations -*- C++ -*-
   2
   3 // Copyright (C) 2001-2013 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 /*
  26  *
  27  * Copyright (c) 1994
  28  * Hewlett-Packard Company
  29  *
  30  * Permission to use, copy, modify, distribute and sell this software
  31  * and its documentation for any purpose is hereby granted without fee,
  32  * provided that the above copyright notice appear in all copies and
  33  * that both that copyright notice and this permission notice appear
  34  * in supporting documentation.  Hewlett-Packard Company makes no
  35  * representations about the suitability of this software for any
  36  * purpose.  It is provided "as is" without express or implied warranty.
  37  *
  38  *
  39  * Copyright (c) 1996-1998
  40  * Silicon Graphics Computer Systems, Inc.
  41  *
  42  * Permission to use, copy, modify, distribute and sell this software
  43  * and its documentation for any purpose is hereby granted without fee,
  44  * provided that the above copyright notice appear in all copies and
  45  * that both that copyright notice and this permission notice appear
  46  * in supporting documentation.  Silicon Graphics makes no
  47  * representations about the suitability of this software for any
  48  * purpose.  It is provided "as is" without express or implied warranty.
  49  */
  50
  51 /** @file bits/stl_function.h
  52  *  This is an internal header file, included by other library headers.
  53  *  Do not attempt to use it directly. @headername{functional}
  54  */
  55
  56 #ifndef _STL_FUNCTION_H
  57 #define _STL_FUNCTION_H 1
  58
  59 namespace std _GLIBCXX_VISIBILITY(default)
  60 {
  61 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  62
  63   // 20.3.1 base classes
  64   /** @defgroup functors Function Objects
  65    * @ingroup utilities
  66    *
  67    *  Function objects, or @e functors, are objects with an @c operator()
  68    *  defined and accessible.  They can be passed as arguments to algorithm
  69    *  templates and used in place of a function pointer.  Not only is the
  70    *  resulting expressiveness of the library increased, but the generated
  71    *  code can be more efficient than what you might write by hand.  When we
  72    *  refer to @a functors, then, generally we include function pointers in
  73    *  the description as well.
  74    *
  75    *  Often, functors are only created as temporaries passed to algorithm
  76    *  calls, rather than being created as named variables.
  77    *
  78    *  Two examples taken from the standard itself follow.  To perform a
  79    *  by-element addition of two vectors @c a and @c b containing @c double,
  80    *  and put the result in @c a, use
  81    *  \code
  82    *  transform (a.begin(), a.end(), b.begin(), a.begin(), plus<double>());
  83    *  \endcode
  84    *  To negate every element in @c a, use
  85    *  \code
  86    *  transform(a.begin(), a.end(), a.begin(), negate<double>());
  87    *  \endcode
  88    *  The addition and negation functions will be inlined directly.
  89    *
  90    *  The standard functors are derived from structs named @c unary_function
  91    *  and @c binary_function.  These two classes contain nothing but typedefs,
  92    *  to aid in generic (template) programming.  If you write your own
  93    *  functors, you might consider doing the same.
  94    *
  95    *  @{
  96    */
  97   /**
  98    *  This is one of the @link functors functor base classes@endlink.
  99    */
 100   template<typename _Arg, typename _Result>
 101     struct unary_function
 102     {
 103       /// @c argument_type is the type of the argument
 104       typedef _Arg      argument_type;
 105
 106       /// @c result_type is the return type
 107       typedef _Result   result_type;
 108     };
 109
 110   /**
 111    *  This is one of the @link functors functor base classes@endlink.
 112    */
 113   template<typename _Arg1, typename _Arg2, typename _Result>
 114     struct binary_function
 115     {
 116       /// @c first_argument_type is the type of the first argument
 117       typedef _Arg1     first_argument_type;
 118
 119       /// @c second_argument_type is the type of the second argument
 120       typedef _Arg2     second_argument_type;
 121
 122       /// @c result_type is the return type
 123       typedef _Result   result_type;
 124     };
 125   /** @}  */
 126
 127   // 20.3.2 arithmetic
 128   /** @defgroup arithmetic_functors Arithmetic Classes
 129    * @ingroup functors
 130    *
 131    *  Because basic math often needs to be done during an algorithm,
 132    *  the library provides functors for those operations.  See the
 133    *  documentation for @link functors the base classes@endlink
 134    *  for examples of their use.
 135    *
 136    *  @{
 137    */
 138   /// One of the @link arithmetic_functors math functors@endlink.
 139   template<typename _Tp>
 140     struct plus : public binary_function<_Tp, _Tp, _Tp>
 141     {
 142       _Tp
 143       operator()(const _Tp& __x, const _Tp& __y) const
 144       { return __x + __y; }
 145     };
 146
 147   /// One of the @link arithmetic_functors math functors@endlink.
 148   template<typename _Tp>
 149     struct minus : public binary_function<_Tp, _Tp, _Tp>
 150     {
 151       _Tp
 152       operator()(const _Tp& __x, const _Tp& __y) const
 153       { return __x - __y; }
 154     };
 155
 156   /// One of the @link arithmetic_functors math functors@endlink.
 157   template<typename _Tp>
 158     struct multiplies : public binary_function<_Tp, _Tp, _Tp>
 159     {
 160       _Tp
 161       operator()(const _Tp& __x, const _Tp& __y) const
 162       { return __x * __y; }
 163     };
 164
 165   /// One of the @link arithmetic_functors math functors@endlink.
 166   template<typename _Tp>
 167     struct divides : public binary_function<_Tp, _Tp, _Tp>
 168     {
 169       _Tp
 170       operator()(const _Tp& __x, const _Tp& __y) const
 171       { return __x / __y; }
 172     };
 173
 174   /// One of the @link arithmetic_functors math functors@endlink.
 175   template<typename _Tp>
 176     struct modulus : public binary_function<_Tp, _Tp, _Tp>
 177     {
 178       _Tp
 179       operator()(const _Tp& __x, const _Tp& __y) const
 180       { return __x % __y; }
 181     };
 182
 183   /// One of the @link arithmetic_functors math functors@endlink.
 184   template<typename _Tp>
 185     struct negate : public unary_function<_Tp, _Tp>
 186     {
 187       _Tp
 188       operator()(const _Tp& __x) const
 189       { return -__x; }
 190     };
 191   /** @}  */
 192
 193   // 20.3.3 comparisons
 194   /** @defgroup comparison_functors Comparison Classes
 195    * @ingroup functors
 196    *
 197    *  The library provides six wrapper functors for all the basic comparisons
 198    *  in C++, like @c <.
 199    *
 200    *  @{
 201    */
 202   /// One of the @link comparison_functors comparison functors@endlink.
 203   template<typename _Tp>
 204     struct equal_to : public binary_function<_Tp, _Tp, bool>
 205     {
 206       bool
 207       operator()(const _Tp& __x, const _Tp& __y) const
 208       { return __x == __y; }
 209     };
 210
 211   /// One of the @link comparison_functors comparison functors@endlink.
 212   template<typename _Tp>
 213     struct not_equal_to : public binary_function<_Tp, _Tp, bool>
 214     {
 215       bool
 216       operator()(const _Tp& __x, const _Tp& __y) const
 217       { return __x != __y; }
 218     };
 219
 220   /// One of the @link comparison_functors comparison functors@endlink.
 221   template<typename _Tp>
 222     struct greater : public binary_function<_Tp, _Tp, bool>
 223     {
 224       bool
 225       operator()(const _Tp& __x, const _Tp& __y) const
 226       { return __x > __y; }
 227     };
 228
 229   /// One of the @link comparison_functors comparison functors@endlink.
 230   template<typename _Tp>
 231     struct less : public binary_function<_Tp, _Tp, bool>
 232     {
 233       bool
 234       operator()(const _Tp& __x, const _Tp& __y) const
 235       { return __x < __y; }
 236     };
 237
 238   /// One of the @link comparison_functors comparison functors@endlink.
 239   template<typename _Tp>
 240     struct greater_equal : public binary_function<_Tp, _Tp, bool>
 241     {
 242       bool
 243       operator()(const _Tp& __x, const _Tp& __y) const
 244       { return __x >= __y; }
 245     };
 246
 247   /// One of the @link comparison_functors comparison functors@endlink.
 248   template<typename _Tp>
 249     struct less_equal : public binary_function<_Tp, _Tp, bool>
 250     {
 251       bool
 252       operator()(const _Tp& __x, const _Tp& __y) const
 253       { return __x <= __y; }
 254     };
 255   /** @}  */
 256
 257   // 20.3.4 logical operations
 258   /** @defgroup logical_functors Boolean Operations Classes
 259    * @ingroup functors
 260    *
 261    *  Here are wrapper functors for Boolean operations: @c &&, @c ||,
 262    *  and @c !.
 263    *
 264    *  @{
 265    */
 266   /// One of the @link logical_functors Boolean operations functors@endlink.
 267   template<typename _Tp>
 268     struct logical_and : public binary_function<_Tp, _Tp, bool>
 269     {
 270       bool
 271       operator()(const _Tp& __x, const _Tp& __y) const
 272       { return __x && __y; }
 273     };
 274
 275   /// One of the @link logical_functors Boolean operations functors@endlink.
 276   template<typename _Tp>
 277     struct logical_or : public binary_function<_Tp, _Tp, bool>
 278     {
 279       bool
 280       operator()(const _Tp& __x, const _Tp& __y) const
 281       { return __x || __y; }
 282     };
 283
 284   /// One of the @link logical_functors Boolean operations functors@endlink.
 285   template<typename _Tp>
 286     struct logical_not : public unary_function<_Tp, bool>
 287     {
 288       bool
 289       operator()(const _Tp& __x) const
 290       { return !__x; }
 291     };
 292   /** @}  */
 293
 294   // _GLIBCXX_RESOLVE_LIB_DEFECTS
 295   // DR 660. Missing Bitwise Operations.
 296   template<typename _Tp>
 297     struct bit_and : public binary_function<_Tp, _Tp, _Tp>
 298     {
 299       _Tp
 300       operator()(const _Tp& __x, const _Tp& __y) const
 301       { return __x & __y; }
 302     };
 303
 304   template<typename _Tp>
 305     struct bit_or : public binary_function<_Tp, _Tp, _Tp>
 306     {
 307       _Tp
 308       operator()(const _Tp& __x, const _Tp& __y) const
 309       { return __x | __y; }
 310     };
 311
 312   template<typename _Tp>
 313     struct bit_xor : public binary_function<_Tp, _Tp, _Tp>
 314     {
 315       _Tp
 316       operator()(const _Tp& __x, const _Tp& __y) const
 317       { return __x ^ __y; }
 318     };
 319
 320   // 20.3.5 negators
 321   /** @defgroup negators Negators
 322    * @ingroup functors
 323    *
 324    *  The functions @c not1 and @c not2 each take a predicate functor
 325    *  and return an instance of @c unary_negate or
 326    *  @c binary_negate, respectively.  These classes are functors whose
 327    *  @c operator() performs the stored predicate function and then returns
 328    *  the negation of the result.
 329    *
 330    *  For example, given a vector of integers and a trivial predicate,
 331    *  \code
 332    *  struct IntGreaterThanThree
 333    *    : public std::unary_function<int, bool>
 334    *  {
 335    *      bool operator() (int x) { return x > 3; }
 336    *  };
 337    *
 338    *  std::find_if (v.begin(), v.end(), not1(IntGreaterThanThree()));
 339    *  \endcode
 340    *  The call to @c find_if will locate the first index (i) of @c v for which
 341    *  <code>!(v[i] > 3)</code> is true.
 342    *
 343    *  The not1/unary_negate combination works on predicates taking a single
 344    *  argument.  The not2/binary_negate combination works on predicates which
 345    *  take two arguments.
 346    *
 347    *  @{
 348    */
 349   /// One of the @link negators negation functors@endlink.
 350   template<typename _Predicate>
 351     class unary_negate
 352     : public unary_function<typename _Predicate::argument_type, bool>
 353     {
 354     protected:
 355       _Predicate _M_pred;
 356
 357     public:
 358       explicit
 359       unary_negate(const _Predicate& __x) : _M_pred(__x) { }
 360
 361       bool
 362       operator()(const typename _Predicate::argument_type& __x) const
 363       { return !_M_pred(__x); }
 364     };
 365
 366   /// One of the @link negators negation functors@endlink.
 367   template<typename _Predicate>
 368     inline unary_negate<_Predicate>
 369     not1(const _Predicate& __pred)
 370     { return unary_negate<_Predicate>(__pred); }
 371
 372   /// One of the @link negators negation functors@endlink.
 373   template<typename _Predicate>
 374     class binary_negate
 375     : public binary_function<typename _Predicate::first_argument_type,
 376                              typename _Predicate::second_argument_type, bool>
 377     {
 378     protected:
 379       _Predicate _M_pred;
 380
 381     public:
 382       explicit
 383       binary_negate(const _Predicate& __x) : _M_pred(__x) { }
 384
 385       bool
 386       operator()(const typename _Predicate::first_argument_type& __x,
 387                  const typename _Predicate::second_argument_type& __y) const
 388       { return !_M_pred(__x, __y); }
 389     };
 390
 391   /// One of the @link negators negation functors@endlink.
 392   template<typename _Predicate>
 393     inline binary_negate<_Predicate>
 394     not2(const _Predicate& __pred)
 395     { return binary_negate<_Predicate>(__pred); }
 396   /** @}  */
 397
 398   // 20.3.7 adaptors pointers functions
 399   /** @defgroup pointer_adaptors Adaptors for pointers to functions
 400    * @ingroup functors
 401    *
 402    *  The advantage of function objects over pointers to functions is that
 403    *  the objects in the standard library declare nested typedefs describing
 404    *  their argument and result types with uniform names (e.g., @c result_type
 405    *  from the base classes @c unary_function and @c binary_function).
 406    *  Sometimes those typedefs are required, not just optional.
 407    *
 408    *  Adaptors are provided to turn pointers to unary (single-argument) and
 409    *  binary (double-argument) functions into function objects.  The
 410    *  long-winded functor @c pointer_to_unary_function is constructed with a
 411    *  function pointer @c f, and its @c operator() called with argument @c x
 412    *  returns @c f(x).  The functor @c pointer_to_binary_function does the same
 413    *  thing, but with a double-argument @c f and @c operator().
 414    *
 415    *  The function @c ptr_fun takes a pointer-to-function @c f and constructs
 416    *  an instance of the appropriate functor.
 417    *
 418    *  @{
 419    */
 420   /// One of the @link pointer_adaptors adaptors for function pointers@endlink.
 421   template<typename _Arg, typename _Result>
 422     class pointer_to_unary_function : public unary_function<_Arg, _Result>
 423     {
 424     protected:
 425       _Result (*_M_ptr)(_Arg);
 426
 427     public:
 428       pointer_to_unary_function() { }
 429
 430       explicit
 431       pointer_to_unary_function(_Result (*__x)(_Arg))
 432       : _M_ptr(__x) { }
 433
 434       _Result
 435       operator()(_Arg __x) const
 436       { return _M_ptr(__x); }
 437     };
 438
 439   /// One of the @link pointer_adaptors adaptors for function pointers@endlink.
 440   template<typename _Arg, typename _Result>
 441     inline pointer_to_unary_function<_Arg, _Result>
 442     ptr_fun(_Result (*__x)(_Arg))
 443     { return pointer_to_unary_function<_Arg, _Result>(__x); }
 444
 445   /// One of the @link pointer_adaptors adaptors for function pointers@endlink.
 446   template<typename _Arg1, typename _Arg2, typename _Result>
 447     class pointer_to_binary_function
 448     : public binary_function<_Arg1, _Arg2, _Result>
 449     {
 450     protected:
 451       _Result (*_M_ptr)(_Arg1, _Arg2);
 452
 453     public:
 454       pointer_to_binary_function() { }
 455
 456       explicit
 457       pointer_to_binary_function(_Result (*__x)(_Arg1, _Arg2))
 458       : _M_ptr(__x) { }
 459
 460       _Result
 461       operator()(_Arg1 __x, _Arg2 __y) const
 462       { return _M_ptr(__x, __y); }
 463     };
 464
 465   /// One of the @link pointer_adaptors adaptors for function pointers@endlink.
 466   template<typename _Arg1, typename _Arg2, typename _Result>
 467     inline pointer_to_binary_function<_Arg1, _Arg2, _Result>
 468     ptr_fun(_Result (*__x)(_Arg1, _Arg2))
 469     { return pointer_to_binary_function<_Arg1, _Arg2, _Result>(__x); }
 470   /** @}  */
 471
 472   template<typename _Tp>
 473     struct _Identity
 474     : public unary_function<_Tp,_Tp>
 475     {
 476       _Tp&
 477       operator()(_Tp& __x) const
 478       { return __x; }
 479
 480       const _Tp&
 481       operator()(const _Tp& __x) const
 482       { return __x; }
 483     };
 484
 485   template<typename _Pair>
 486     struct _Select1st
 487     : public unary_function<_Pair, typename _Pair::first_type>
 488     {
 489       typename _Pair::first_type&
 490       operator()(_Pair& __x) const
 491       { return __x.first; }
 492
 493       const typename _Pair::first_type&
 494       operator()(const _Pair& __x) const
 495       { return __x.first; }
 496
 497 #if __cplusplus >= 201103L
 498       template<typename _Pair2>
 499         typename _Pair2::first_type&
 500         operator()(_Pair2& __x) const
 501         { return __x.first; }
 502
 503       template<typename _Pair2>
 504         const typename _Pair2::first_type&
 505         operator()(const _Pair2& __x) const
 506         { return __x.first; }
 507 #endif
 508     };
 509
 510   template<typename _Pair>
 511     struct _Select2nd
 512     : public unary_function<_Pair, typename _Pair::second_type>
 513     {
 514       typename _Pair::second_type&
 515       operator()(_Pair& __x) const
 516       { return __x.second; }
 517
 518       const typename _Pair::second_type&
 519       operator()(const _Pair& __x) const
 520       { return __x.second; }
 521     };
 522
 523   // 20.3.8 adaptors pointers members
 524   /** @defgroup memory_adaptors Adaptors for pointers to members
 525    * @ingroup functors
 526    *
 527    *  There are a total of 8 = 2^3 function objects in this family.
 528    *   (1) Member functions taking no arguments vs member functions taking
 529    *        one argument.
 530    *   (2) Call through pointer vs call through reference.
 531    *   (3) Const vs non-const member function.
 532    *
 533    *  All of this complexity is in the function objects themselves.  You can
 534    *   ignore it by using the helper function mem_fun and mem_fun_ref,
 535    *   which create whichever type of adaptor is appropriate.
 536    *
 537    *  @{
 538    */
 539   /// One of the @link memory_adaptors adaptors for member
 540   /// pointers@endlink.
 541   template<typename _Ret, typename _Tp>
 542     class mem_fun_t : public unary_function<_Tp*, _Ret>
 543     {
 544     public:
 545       explicit
 546       mem_fun_t(_Ret (_Tp::*__pf)())
 547       : _M_f(__pf) { }
 548
 549       _Ret
 550       operator()(_Tp* __p) const
 551       { return (__p->*_M_f)(); }
 552
 553     private:
 554       _Ret (_Tp::*_M_f)();
 555     };
 556
 557   /// One of the @link memory_adaptors adaptors for member
 558   /// pointers@endlink.
 559   template<typename _Ret, typename _Tp>
 560     class const_mem_fun_t : public unary_function<const _Tp*, _Ret>
 561     {
 562     public:
 563       explicit
 564       const_mem_fun_t(_Ret (_Tp::*__pf)() const)
 565       : _M_f(__pf) { }
 566
 567       _Ret
 568       operator()(const _Tp* __p) const
 569       { return (__p->*_M_f)(); }
 570
 571     private:
 572       _Ret (_Tp::*_M_f)() const;
 573     };
 574
 575   /// One of the @link memory_adaptors adaptors for member
 576   /// pointers@endlink.
 577   template<typename _Ret, typename _Tp>
 578     class mem_fun_ref_t : public unary_function<_Tp, _Ret>
 579     {
 580     public:
 581       explicit
 582       mem_fun_ref_t(_Ret (_Tp::*__pf)())
 583       : _M_f(__pf) { }
 584
 585       _Ret
 586       operator()(_Tp& __r) const
 587       { return (__r.*_M_f)(); }
 588
 589     private:
 590       _Ret (_Tp::*_M_f)();
 591   };
 592
 593   /// One of the @link memory_adaptors adaptors for member
 594   /// pointers@endlink.
 595   template<typename _Ret, typename _Tp>
 596     class const_mem_fun_ref_t : public unary_function<_Tp, _Ret>
 597     {
 598     public:
 599       explicit
 600       const_mem_fun_ref_t(_Ret (_Tp::*__pf)() const)
 601       : _M_f(__pf) { }
 602
 603       _Ret
 604       operator()(const _Tp& __r) const
 605       { return (__r.*_M_f)(); }
 606
 607     private:
 608       _Ret (_Tp::*_M_f)() const;
 609     };
 610
 611   /// One of the @link memory_adaptors adaptors for member
 612   /// pointers@endlink.
 613   template<typename _Ret, typename _Tp, typename _Arg>
 614     class mem_fun1_t : public binary_function<_Tp*, _Arg, _Ret>
 615     {
 616     public:
 617       explicit
 618       mem_fun1_t(_Ret (_Tp::*__pf)(_Arg))
 619       : _M_f(__pf) { }
 620
 621       _Ret
 622       operator()(_Tp* __p, _Arg __x) const
 623       { return (__p->*_M_f)(__x); }
 624
 625     private:
 626       _Ret (_Tp::*_M_f)(_Arg);
 627     };
 628
 629   /// One of the @link memory_adaptors adaptors for member
 630   /// pointers@endlink.
 631   template<typename _Ret, typename _Tp, typename _Arg>
 632     class const_mem_fun1_t : public binary_function<const _Tp*, _Arg, _Ret>
 633     {
 634     public:
 635       explicit
 636       const_mem_fun1_t(_Ret (_Tp::*__pf)(_Arg) const)
 637       : _M_f(__pf) { }
 638
 639       _Ret
 640       operator()(const _Tp* __p, _Arg __x) const
 641       { return (__p->*_M_f)(__x); }
 642
 643     private:
 644       _Ret (_Tp::*_M_f)(_Arg) const;
 645     };
 646
 647   /// One of the @link memory_adaptors adaptors for member
 648   /// pointers@endlink.
 649   template<typename _Ret, typename _Tp, typename _Arg>
 650     class mem_fun1_ref_t : public binary_function<_Tp, _Arg, _Ret>
 651     {
 652     public:
 653       explicit
 654       mem_fun1_ref_t(_Ret (_Tp::*__pf)(_Arg))
 655       : _M_f(__pf) { }
 656
 657       _Ret
 658       operator()(_Tp& __r, _Arg __x) const
 659       { return (__r.*_M_f)(__x); }
 660
 661     private:
 662       _Ret (_Tp::*_M_f)(_Arg);
 663     };
 664
 665   /// One of the @link memory_adaptors adaptors for member
 666   /// pointers@endlink.
 667   template<typename _Ret, typename _Tp, typename _Arg>
 668     class const_mem_fun1_ref_t : public binary_function<_Tp, _Arg, _Ret>
 669     {
 670     public:
 671       explicit
 672       const_mem_fun1_ref_t(_Ret (_Tp::*__pf)(_Arg) const)
 673       : _M_f(__pf) { }
 674
 675       _Ret
 676       operator()(const _Tp& __r, _Arg __x) const
 677       { return (__r.*_M_f)(__x); }
 678
 679     private:
 680       _Ret (_Tp::*_M_f)(_Arg) const;
 681     };
 682
 683   // Mem_fun adaptor helper functions.  There are only two:
 684   // mem_fun and mem_fun_ref.
 685   template<typename _Ret, typename _Tp>
 686     inline mem_fun_t<_Ret, _Tp>
 687     mem_fun(_Ret (_Tp::*__f)())
 688     { return mem_fun_t<_Ret, _Tp>(__f); }
 689
 690   template<typename _Ret, typename _Tp>
 691     inline const_mem_fun_t<_Ret, _Tp>
 692     mem_fun(_Ret (_Tp::*__f)() const)
 693     { return const_mem_fun_t<_Ret, _Tp>(__f); }
 694
 695   template<typename _Ret, typename _Tp>
 696     inline mem_fun_ref_t<_Ret, _Tp>
 697     mem_fun_ref(_Ret (_Tp::*__f)())
 698     { return mem_fun_ref_t<_Ret, _Tp>(__f); }
 699
 700   template<typename _Ret, typename _Tp>
 701     inline const_mem_fun_ref_t<_Ret, _Tp>
 702     mem_fun_ref(_Ret (_Tp::*__f)() const)
 703     { return const_mem_fun_ref_t<_Ret, _Tp>(__f); }
 704
 705   template<typename _Ret, typename _Tp, typename _Arg>
 706     inline mem_fun1_t<_Ret, _Tp, _Arg>
 707     mem_fun(_Ret (_Tp::*__f)(_Arg))
 708     { return mem_fun1_t<_Ret, _Tp, _Arg>(__f); }
 709
 710   template<typename _Ret, typename _Tp, typename _Arg>
 711     inline const_mem_fun1_t<_Ret, _Tp, _Arg>
 712     mem_fun(_Ret (_Tp::*__f)(_Arg) const)
 713     { return const_mem_fun1_t<_Ret, _Tp, _Arg>(__f); }
 714
 715   template<typename _Ret, typename _Tp, typename _Arg>
 716     inline mem_fun1_ref_t<_Ret, _Tp, _Arg>
 717     mem_fun_ref(_Ret (_Tp::*__f)(_Arg))
 718     { return mem_fun1_ref_t<_Ret, _Tp, _Arg>(__f); }
 719
 720   template<typename _Ret, typename _Tp, typename _Arg>
 721     inline const_mem_fun1_ref_t<_Ret, _Tp, _Arg>
 722     mem_fun_ref(_Ret (_Tp::*__f)(_Arg) const)
 723     { return const_mem_fun1_ref_t<_Ret, _Tp, _Arg>(__f); }
 724
 725   /** @}  */
 726
 727 _GLIBCXX_END_NAMESPACE_VERSION
 728 } // namespace
 729
 730 #if (__cplusplus < 201103L) || _GLIBCXX_USE_DEPRECATED
 731 # include <backward/binders.h>
 732 #endif
 733
 734 #endif /* _STL_FUNCTION_H */