ceph/src/boost/boost/function_types/result_type.hpp

   1
   2 // (C) Copyright Tobias Schwinger
   3 //
   4 // Use modification and distribution are subject to the boost Software License,
   5 // Version 1.0. (See http://www.boost.org/LICENSE_1_0.txt).
   6
   7 //------------------------------------------------------------------------------
   8
   9 #ifndef BOOST_FT_RESULT_TYPE_HPP_INCLUDED
  10 #define BOOST_FT_RESULT_TYPE_HPP_INCLUDED
  11
  12 #include <boost/blank.hpp>
  13 #include <boost/mpl/if.hpp>
  14
  15 #include <boost/mpl/aux_/lambda_support.hpp>
  16
  17 #include <boost/mpl/at.hpp>
  18
  19 #include <boost/function_types/is_callable_builtin.hpp>
  20 #include <boost/function_types/components.hpp>
  21
  22 namespace boost
  23 {
  24   namespace function_types
  25   {
  26     template< typename T > struct result_type;
  27
  28     namespace detail
  29     {
  30       template<typename T> struct result_type_impl
  31         : mpl::at_c
  32           < typename function_types::components<T>::types, 0 >
  33       { };
  34     }
  35
  36     template<typename T> struct result_type
  37       : mpl::if_
  38         < function_types::is_callable_builtin<T>
  39         , detail::result_type_impl<T>, boost::blank
  40         >::type
  41     {
  42       BOOST_MPL_AUX_LAMBDA_SUPPORT(1,result_type,(T))
  43     };
  44   }
  45 }
  46
  47 #endif
  48