ceph/src/boost/boost/spirit/home/x3/support/utility/is_callable.hpp

   1 /*//////////////////////////////////////////////////////////////////////////////
   2     Copyright (c) 2014 Jamboree
   3
   4     Distributed under the Boost Software License, Version 1.0. (See accompanying
   5     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 //////////////////////////////////////////////////////////////////////////////*/
   7 #ifndef BOOST_SPIRIT_X3_IS_CALLABLE_HPP_INCLUDED
   8 #define BOOST_SPIRIT_X3_IS_CALLABLE_HPP_INCLUDED
   9
  10 #include <boost/mpl/bool.hpp>
  11 #include <boost/spirit/home/x3/support/utility/sfinae.hpp>
  12
  13 namespace boost { namespace spirit { namespace x3 { namespace detail
  14 {
  15     template <typename Sig, typename Enable = void>
  16     struct is_callable_impl : mpl::false_ {};
  17
  18     template <typename F, typename... A>
  19     struct is_callable_impl<F(A...), typename disable_if_substitution_failure<
  20         decltype(std::declval<F>()(std::declval<A>()...))>::type>
  21       : mpl::true_
  22     {};
  23 }}}}
  24
  25 namespace boost { namespace spirit { namespace x3
  26 {
  27     template <typename Sig>
  28     struct is_callable;
  29
  30     template <typename F, typename... A>
  31     struct is_callable<F(A...)> : detail::is_callable_impl<F(A...)> {};
  32 }}}
  33
  34
  35 #endif