/*//////////////////////////////////////////////////////////////////////////////
    Copyright (c) 2014 Jamboree

    Distributed under the Boost Software License, Version 1.0. (See accompanying
    file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//////////////////////////////////////////////////////////////////////////////*/
#ifndef BOOST_SPIRIT_X3_IS_CALLABLE_HPP_INCLUDED
#define BOOST_SPIRIT_X3_IS_CALLABLE_HPP_INCLUDED

#include <boost/mpl/bool.hpp>
#include <boost/spirit/home/x3/support/utility/sfinae.hpp>

namespace boost { namespace spirit { namespace x3 { namespace detail
{
    template <typename Sig, typename Enable = void>
    struct is_callable_impl : mpl::false_ {};

    template <typename F, typename... A>
    struct is_callable_impl<F(A...), typename disable_if_substitution_failure<
        decltype(std::declval<F>()(std::declval<A>()...))>::type>
      : mpl::true_
    {};
}}}}

namespace boost { namespace spirit { namespace x3
{
    template <typename Sig>
    struct is_callable;

    template <typename F, typename... A>
    struct is_callable<F(A...)> : detail::is_callable_impl<F(A...)> {};
}}}


#endif