boost/ptr_container/indirect_fun.hpp

   1 //
   2 // Boost.Pointer Container
   3 //
   4 //  Copyright Thorsten Ottosen 2003-2007. Use, modification and
   5 //  distribution is subject to the Boost Software License, Version
   6 //  1.0. (See accompanying file LICENSE_1_0.txt or copy at
   7 //  http://www.boost.org/LICENSE_1_0.txt)
   8 //
   9 // For more information, see http://www.boost.org/libs/ptr_container/
  10 //
  11
  12 #ifndef BOOST_PTR_CONTAINER_INDIRECT_FUN_HPP
  13 #define BOOST_PTR_CONTAINER_INDIRECT_FUN_HPP
  14
  15 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
  16     #pragma once
  17 #endif
  18
  19 #include <boost/config.hpp>
  20
  21 #ifdef BOOST_NO_SFINAE
  22 #else
  23 #include <boost/utility/result_of.hpp>
  24 #include <boost/pointee.hpp>
  25 #endif // BOOST_NO_SFINAE
  26
  27 #include <boost/assert.hpp>
  28 #include <functional>
  29
  30
  31 namespace boost
  32 {
  33
  34
  35     template
  36     <
  37               class Fun
  38 #ifdef BOOST_NO_SFINAE
  39             , class Result = bool
  40 #endif
  41     >
  42     class indirect_fun
  43     {
  44         Fun fun;
  45     public:
  46         indirect_fun() : fun(Fun())
  47         { }
  48
  49         indirect_fun( Fun f ) : fun(f)
  50         { }
  51
  52         template< class T >
  53 #ifdef BOOST_NO_SFINAE
  54         Result
  55 #else
  56         BOOST_DEDUCED_TYPENAME result_of< Fun( BOOST_DEDUCED_TYPENAME pointee<T>::type& ) >::type
  57 #endif
  58         operator()( const T& r ) const
  59         {
  60             return fun( *r );
  61         }
  62
  63         template< class T, class U >
  64 #ifdef BOOST_NO_SFINAE
  65         Result
  66 #else
  67         BOOST_DEDUCED_TYPENAME result_of< Fun( BOOST_DEDUCED_TYPENAME pointee<T>::type&,
  68                                                BOOST_DEDUCED_TYPENAME pointee<U>::type& ) >::type
  69 #endif
  70         operator()( const T& r, const U& r2 ) const
  71         {
  72             return fun( *r, *r2 );
  73         }
  74     };
  75
  76     template< class Fun >
  77     inline indirect_fun<Fun> make_indirect_fun( Fun f )
  78     {
  79         return indirect_fun<Fun>( f );
  80     }
  81
  82
  83     template
  84     <
  85         class Fun,
  86         class Arg1,
  87         class Arg2 = Arg1
  88 #ifdef BOOST_NO_SFINAE
  89       , class Result = bool
  90 #endif
  91     >
  92     class void_ptr_indirect_fun
  93     {
  94         Fun fun;
  95     public:
  96
  97         void_ptr_indirect_fun() : fun(Fun())
  98         { }
  99
 100         void_ptr_indirect_fun( Fun f ) : fun(f)
 101         { }
 102 #ifdef BOOST_NO_SFINAE
 103         Result
 104 #else
 105         BOOST_DEDUCED_TYPENAME result_of< Fun( Arg1& ) >::type
 106 #endif
 107         operator()( const void* r ) const
 108         {
 109             BOOST_ASSERT( r != 0 );
 110             return fun( * static_cast<const Arg1*>( r ) );
 111         }
 112
 113 #ifdef BOOST_NO_SFINAE
 114         Result
 115 #else
 116         BOOST_DEDUCED_TYPENAME result_of< Fun( Arg1&, Arg2& ) >::type
 117 #endif
 118         operator()( const void* l, const void* r ) const
 119         {
 120             BOOST_ASSERT( l != 0 && r != 0 );
 121             return fun( * static_cast<const Arg1*>( l ), * static_cast<const Arg2*>( r ) );
 122         }
 123     };
 124
 125     template< class Arg, class Fun >
 126     inline void_ptr_indirect_fun<Fun,Arg> make_void_ptr_indirect_fun( Fun f )
 127     {
 128         return void_ptr_indirect_fun<Fun,Arg>( f );
 129     }
 130
 131 } // namespace 'boost'
 132
 133 #endif