1 // ------------------------------------------------------------------------------

     2 // Copyright (c) 2000 Cadenza New Zealand Ltd

     3 // Distributed under the Boost Software License, Version 1.0. (See accompany-

     4 // ing file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

     5 // ------------------------------------------------------------------------------

     6 // Boost functional.hpp header file

     7 // See http://www.boost.org/libs/functional for documentation.

     8 // ------------------------------------------------------------------------------

     9 // $Id: functional.hpp 36246 2006-12-02 14:17:26Z andreas_huber69 $

    10 // ------------------------------------------------------------------------------

    11 

    12 #ifndef BOOST_FUNCTIONAL_HPP

    13 #define BOOST_FUNCTIONAL_HPP

    14 

    15 #include <boost/config.hpp>

    16 #include <boost/call_traits.hpp>

    17 #include <functional>

    18 

    19 namespace boost

    20 {

    21 #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

    22     // --------------------------------------------------------------------------

    23     // The following traits classes allow us to avoid the need for ptr_fun

    24     // because the types of arguments and the result of a function can be 

    25     // deduced.

    26     //

    27     // In addition to the standard types defined in unary_function and 

    28     // binary_function, we add

    29     //

    30     // - function_type, the type of the function or function object itself.

    31     //

    32     // - param_type, the type that should be used for passing the function or

    33     //   function object as an argument.

    34     // --------------------------------------------------------------------------

    35     namespace detail

    36     {

    37         template <class Operation>

    38         struct unary_traits_imp;

    39         

    40         template <class Operation>

    41         struct unary_traits_imp<Operation*>

    42         {

    43             typedef Operation                         function_type;

    44             typedef const function_type &             param_type;

    45             typedef typename Operation::result_type   result_type;

    46             typedef typename Operation::argument_type argument_type;

    47         };

    48 

    49         template <class R, class A>

    50         struct unary_traits_imp<R(*)(A)>

    51         {

    52             typedef R (*function_type)(A);

    53             typedef R (*param_type)(A);

    54             typedef R result_type;

    55             typedef A argument_type;

    56         };

    57 

    58         template <class Operation>

    59         struct binary_traits_imp;

    60 

    61         template <class Operation>

    62         struct binary_traits_imp<Operation*>

    63         {

    64             typedef Operation                                function_type;

    65             typedef const function_type &                    param_type;

    66             typedef typename Operation::result_type          result_type;

    67             typedef typename Operation::first_argument_type  first_argument_type;

    68             typedef typename Operation::second_argument_type second_argument_type;

    69         };

    70         

    71         template <class R, class A1, class A2>

    72         struct binary_traits_imp<R(*)(A1,A2)>

    73         {

    74             typedef R (*function_type)(A1,A2);

    75             typedef R (*param_type)(A1,A2);

    76             typedef R result_type;

    77             typedef A1 first_argument_type;

    78             typedef A2 second_argument_type;

    79         };

    80     } // namespace detail

    81     

    82     template <class Operation>

    83     struct unary_traits

    84     {

    85         typedef typename detail::unary_traits_imp<Operation*>::function_type function_type;

    86         typedef typename detail::unary_traits_imp<Operation*>::param_type    param_type;

    87         typedef typename detail::unary_traits_imp<Operation*>::result_type   result_type;

    88         typedef typename detail::unary_traits_imp<Operation*>::argument_type argument_type;

    89     }; 

    90 

    91     template <class R, class A>

    92     struct unary_traits<R(*)(A)>

    93     {

    94         typedef R (*function_type)(A);

    95         typedef R (*param_type)(A);

    96         typedef R result_type;

    97         typedef A argument_type;

    98     };

    99 

   100     template <class Operation>

   101     struct binary_traits

   102     {

   103         typedef typename detail::binary_traits_imp<Operation*>::function_type        function_type;

   104         typedef typename detail::binary_traits_imp<Operation*>::param_type           param_type;

   105         typedef typename detail::binary_traits_imp<Operation*>::result_type          result_type;

   106         typedef typename detail::binary_traits_imp<Operation*>::first_argument_type  first_argument_type;

   107         typedef typename detail::binary_traits_imp<Operation*>::second_argument_type second_argument_type;

   108     };

   109     

   110     template <class R, class A1, class A2>

   111     struct binary_traits<R(*)(A1,A2)>

   112     {

   113         typedef R (*function_type)(A1,A2);

   114         typedef R (*param_type)(A1,A2);

   115         typedef R result_type;

   116         typedef A1 first_argument_type;

   117         typedef A2 second_argument_type;

   118     };

   119 #else // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

   120     // --------------------------------------------------------------------------

   121     // If we have no partial specialisation available, decay to a situation

   122     // that is no worse than in the Standard, i.e., ptr_fun will be required.

   123     // --------------------------------------------------------------------------

   124 

   125     template <class Operation>

   126     struct unary_traits

   127     {

   128         typedef Operation                         function_type;

   129         typedef const Operation&                  param_type;

   130         typedef typename Operation::result_type   result_type;

   131         typedef typename Operation::argument_type argument_type;

   132     }; 

   133     

   134     template <class Operation>

   135     struct binary_traits

   136     {

   137         typedef Operation                                function_type;

   138         typedef const Operation &                        param_type;

   139         typedef typename Operation::result_type          result_type;

   140         typedef typename Operation::first_argument_type  first_argument_type;

   141         typedef typename Operation::second_argument_type second_argument_type;

   142     };    

   143 #endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

   144     

   145     // --------------------------------------------------------------------------

   146     // unary_negate, not1

   147     // --------------------------------------------------------------------------

   148     template <class Predicate>

   149     class unary_negate

   150         : public std::unary_function<typename unary_traits<Predicate>::argument_type,bool>

   151     {

   152       public:

   153         explicit unary_negate(typename unary_traits<Predicate>::param_type x)

   154             :

   155             pred(x)

   156         {}

   157         bool operator()(typename call_traits<typename unary_traits<Predicate>::argument_type>::param_type x) const

   158         {

   159             return !pred(x);

   160         }

   161       private:

   162         typename unary_traits<Predicate>::function_type pred;

   163     };

   164 

   165     template <class Predicate>

   166     unary_negate<Predicate> not1(const Predicate &pred)

   167     {

   168         // The cast is to placate Borland C++Builder in certain circumstances.

   169         // I don't think it should be necessary.

   170         return unary_negate<Predicate>((typename unary_traits<Predicate>::param_type)pred);

   171     }

   172 

   173     template <class Predicate>

   174     unary_negate<Predicate> not1(Predicate &pred)

   175     {

   176         return unary_negate<Predicate>(pred);

   177     }

   178 

   179     // --------------------------------------------------------------------------

   180     // binary_negate, not2

   181     // --------------------------------------------------------------------------

   182     template <class Predicate>

   183     class binary_negate

   184         : public std::binary_function<typename binary_traits<Predicate>::first_argument_type,

   185                                       typename binary_traits<Predicate>::second_argument_type,

   186                                       bool>

   187     {

   188       public:

   189         explicit binary_negate(typename binary_traits<Predicate>::param_type x)

   190             :

   191             pred(x)

   192         {}

   193         bool operator()(typename call_traits<typename binary_traits<Predicate>::first_argument_type>::param_type x,

   194                         typename call_traits<typename binary_traits<Predicate>::second_argument_type>::param_type y) const

   195         {

   196             return !pred(x,y);

   197         }

   198       private:

   199         typename binary_traits<Predicate>::function_type pred;

   200     };

   201 

   202     template <class Predicate>

   203     binary_negate<Predicate> not2(const Predicate &pred)

   204     {

   205         // The cast is to placate Borland C++Builder in certain circumstances.

   206         // I don't think it should be necessary.

   207         return binary_negate<Predicate>((typename binary_traits<Predicate>::param_type)pred);

   208     }

   209 

   210     template <class Predicate>

   211     binary_negate<Predicate> not2(Predicate &pred)

   212     {

   213         return binary_negate<Predicate>(pred);

   214     }

   215         

   216     // --------------------------------------------------------------------------

   217     // binder1st, bind1st

   218     // --------------------------------------------------------------------------

   219     template <class Operation>

   220     class binder1st

   221         : public std::unary_function<typename binary_traits<Operation>::second_argument_type,

   222                                      typename binary_traits<Operation>::result_type>

   223     {       

   224       public:

   225         binder1st(typename binary_traits<Operation>::param_type x,

   226                   typename call_traits<typename binary_traits<Operation>::first_argument_type>::param_type y)

   227             :

   228             op(x), value(y)

   229         {}

   230         

   231         typename binary_traits<Operation>::result_type

   232         operator()(typename call_traits<typename binary_traits<Operation>::second_argument_type>::param_type x) const

   233         {

   234             return op(value, x);

   235         }

   236         

   237       protected:

   238         typename binary_traits<Operation>::function_type op;

   239         typename binary_traits<Operation>::first_argument_type value;

   240     };

   241 

   242     template <class Operation>

   243     inline binder1st<Operation> bind1st(const Operation &op,

   244                                         typename call_traits<

   245                                                     typename binary_traits<Operation>::first_argument_type

   246                                         >::param_type x)

   247     {

   248         // The cast is to placate Borland C++Builder in certain circumstances.

   249         // I don't think it should be necessary.

   250         return binder1st<Operation>((typename binary_traits<Operation>::param_type)op, x);

   251     }

   252 

   253     template <class Operation>

   254     inline binder1st<Operation> bind1st(Operation &op,

   255                                         typename call_traits<

   256                                                     typename binary_traits<Operation>::first_argument_type

   257                                         >::param_type x)

   258     {

   259         return binder1st<Operation>(op, x);

   260     }

   261 

   262     // --------------------------------------------------------------------------

   263     // binder2nd, bind2nd

   264     // --------------------------------------------------------------------------

   265     template <class Operation>

   266     class binder2nd

   267         : public std::unary_function<typename binary_traits<Operation>::first_argument_type,

   268                                      typename binary_traits<Operation>::result_type>

   269     {

   270       public:

   271         binder2nd(typename binary_traits<Operation>::param_type x,

   272                   typename call_traits<typename binary_traits<Operation>::second_argument_type>::param_type y)

   273             :

   274             op(x), value(y)

   275         {}

   276         

   277         typename binary_traits<Operation>::result_type

   278         operator()(typename call_traits<typename binary_traits<Operation>::first_argument_type>::param_type x) const

   279         {

   280             return op(x, value);

   281         }               

   282         

   283       protected:

   284         typename binary_traits<Operation>::function_type op;

   285         typename binary_traits<Operation>::second_argument_type value;

   286     };

   287 

   288     template <class Operation>

   289     inline binder2nd<Operation> bind2nd(const Operation &op,

   290                                         typename call_traits<

   291                                                     typename binary_traits<Operation>::second_argument_type

   292                                         >::param_type x)

   293     {

   294         // The cast is to placate Borland C++Builder in certain circumstances.

   295         // I don't think it should be necessary.

   296         return binder2nd<Operation>((typename binary_traits<Operation>::param_type)op, x);

   297     }

   298 

   299     template <class Operation>

   300     inline binder2nd<Operation> bind2nd(Operation &op,

   301                                         typename call_traits<

   302                                                     typename binary_traits<Operation>::second_argument_type

   303                                         >::param_type x)

   304     {

   305         return binder2nd<Operation>(op, x);

   306     }

   307 

   308     // --------------------------------------------------------------------------

   309     // mem_fun, etc

   310     // --------------------------------------------------------------------------

   311     template <class S, class T>

   312     class mem_fun_t : public std::unary_function<T*, S>

   313     {

   314       public:

   315         explicit mem_fun_t(S (T::*p)())

   316             :

   317             ptr(p)

   318         {}

   319         S operator()(T* p) const

   320         {

   321             return (p->*ptr)();

   322         }

   323       private:

   324         S (T::*ptr)();

   325     };

   326 

   327     template <class S, class T, class A>

   328     class mem_fun1_t : public std::binary_function<T*, A, S>

   329     {

   330       public:   

   331         explicit mem_fun1_t(S (T::*p)(A))

   332             :

   333             ptr(p)

   334         {}

   335         S operator()(T* p, typename call_traits<A>::param_type x) const

   336         {

   337             return (p->*ptr)(x);

   338         }

   339       private:

   340         S (T::*ptr)(A);

   341     };

   342 

   343     template <class S, class T>

   344     class const_mem_fun_t : public std::unary_function<const T*, S>

   345     {

   346       public:

   347         explicit const_mem_fun_t(S (T::*p)() const)

   348             :

   349             ptr(p)

   350         {}

   351         S operator()(const T* p) const

   352         {

   353             return (p->*ptr)();

   354         }

   355       private:

   356         S (T::*ptr)() const;        

   357     };

   358 

   359     template <class S, class T, class A>

   360     class const_mem_fun1_t : public std::binary_function<const T*, A, S>

   361     {

   362       public:

   363         explicit const_mem_fun1_t(S (T::*p)(A) const)

   364             :

   365             ptr(p)

   366         {}

   367         S operator()(const T* p, typename call_traits<A>::param_type x) const

   368         {

   369             return (p->*ptr)(x);

   370         }

   371       private:

   372         S (T::*ptr)(A) const;

   373     };

   374     

   375     template<class S, class T>

   376     inline mem_fun_t<S,T> mem_fun(S (T::*f)())

   377     {

   378         return mem_fun_t<S,T>(f);

   379     }

   380     

   381     template<class S, class T, class A>

   382     inline mem_fun1_t<S,T,A> mem_fun(S (T::*f)(A))

   383     {

   384         return mem_fun1_t<S,T,A>(f);

   385     }

   386 

   387 #ifndef BOOST_NO_POINTER_TO_MEMBER_CONST

   388     template<class S, class T>

   389     inline const_mem_fun_t<S,T> mem_fun(S (T::*f)() const)

   390     {

   391         return const_mem_fun_t<S,T>(f);

   392     }

   393     

   394     template<class S, class T, class A>

   395     inline const_mem_fun1_t<S,T,A> mem_fun(S (T::*f)(A) const)

   396     {

   397         return const_mem_fun1_t<S,T,A>(f);

   398     }

   399 #endif // BOOST_NO_POINTER_TO_MEMBER_CONST

   400 

   401     // --------------------------------------------------------------------------

   402     // mem_fun_ref, etc

   403     // --------------------------------------------------------------------------

   404     template <class S, class T>

   405     class mem_fun_ref_t : public std::unary_function<T&, S>

   406     {

   407       public:

   408         explicit mem_fun_ref_t(S (T::*p)())

   409             :

   410             ptr(p)

   411         {}

   412         S operator()(T& p) const

   413         {

   414             return (p.*ptr)();

   415         }

   416       private:

   417         S (T::*ptr)();

   418     };

   419 

   420     template <class S, class T, class A>

   421     class mem_fun1_ref_t : public std::binary_function<T&, A, S>

   422     {

   423       public:

   424         explicit mem_fun1_ref_t(S (T::*p)(A))

   425             :

   426             ptr(p)

   427         {}

   428         S operator()(T& p, typename call_traits<A>::param_type x) const

   429         {

   430             return (p.*ptr)(x);

   431         }

   432       private:

   433         S (T::*ptr)(A);

   434     };

   435     

   436     template <class S, class T>

   437     class const_mem_fun_ref_t : public std::unary_function<const T&, S>

   438     {

   439       public:

   440         explicit const_mem_fun_ref_t(S (T::*p)() const)

   441             :

   442             ptr(p)

   443         {}

   444         

   445         S operator()(const T &p) const

   446         {

   447             return (p.*ptr)();

   448         }

   449       private:

   450         S (T::*ptr)() const;

   451     };

   452 

   453     template <class S, class T, class A>

   454     class const_mem_fun1_ref_t : public std::binary_function<const T&, A, S>

   455     {

   456       public:

   457         explicit const_mem_fun1_ref_t(S (T::*p)(A) const)

   458             :

   459             ptr(p)

   460         {}

   461 

   462         S operator()(const T& p, typename call_traits<A>::param_type x) const

   463         {

   464             return (p.*ptr)(x);

   465         }

   466       private:

   467         S (T::*ptr)(A) const;

   468     };

   469     

   470     template<class S, class T>

   471     inline mem_fun_ref_t<S,T> mem_fun_ref(S (T::*f)())

   472     {

   473         return mem_fun_ref_t<S,T>(f);

   474     }

   475 

   476     template<class S, class T, class A>

   477     inline mem_fun1_ref_t<S,T,A> mem_fun_ref(S (T::*f)(A))

   478     {

   479         return mem_fun1_ref_t<S,T,A>(f);

   480     }

   481 

   482 #ifndef BOOST_NO_POINTER_TO_MEMBER_CONST

   483     template<class S, class T>

   484     inline const_mem_fun_ref_t<S,T> mem_fun_ref(S (T::*f)() const)

   485     {

   486         return const_mem_fun_ref_t<S,T>(f);

   487     }

   488 

   489     template<class S, class T, class A>

   490     inline const_mem_fun1_ref_t<S,T,A> mem_fun_ref(S (T::*f)(A) const)

   491     {

   492         return const_mem_fun1_ref_t<S,T,A>(f);

   493     }   

   494 #endif // BOOST_NO_POINTER_TO_MEMBER_CONST

   495 

   496     // --------------------------------------------------------------------------

   497     // ptr_fun

   498     // --------------------------------------------------------------------------

   499     template <class Arg, class Result>

   500     class pointer_to_unary_function : public std::unary_function<Arg,Result>

   501     {

   502       public:

   503         explicit pointer_to_unary_function(Result (*f)(Arg))

   504             :

   505             func(f)

   506         {}

   507 

   508         Result operator()(typename call_traits<Arg>::param_type x) const

   509         {

   510             return func(x);

   511         }

   512         

   513       private:

   514         Result (*func)(Arg);

   515     };

   516 

   517     template <class Arg, class Result>

   518     inline pointer_to_unary_function<Arg,Result> ptr_fun(Result (*f)(Arg))

   519     {

   520         return pointer_to_unary_function<Arg,Result>(f);

   521     }

   522 

   523     template <class Arg1, class Arg2, class Result>

   524     class pointer_to_binary_function : public std::binary_function<Arg1,Arg2,Result>

   525     {

   526       public:

   527         explicit pointer_to_binary_function(Result (*f)(Arg1, Arg2))

   528             :

   529             func(f)

   530         {}

   531         

   532         Result operator()(typename call_traits<Arg1>::param_type x, typename call_traits<Arg2>::param_type y) const

   533         {

   534             return func(x,y);

   535         }

   536         

   537       private:

   538         Result (*func)(Arg1, Arg2);

   539     };

   540 

   541     template <class Arg1, class Arg2, class Result>

   542     inline pointer_to_binary_function<Arg1,Arg2,Result> ptr_fun(Result (*f)(Arg1, Arg2))

   543     {

   544         return pointer_to_binary_function<Arg1,Arg2,Result>(f);

   545     }

   546 } // namespace boost

   547 

   548 #endif