functional/range/empty.hpp

0001 ///////////////////////////////////////////////////////////////////////////////
0002 /// \file empty.hpp
0003 /// Proto callables for boost::empty()
0004 //
0005 //  Copyright 2012 Eric Niebler. Distributed under the Boost
0006 //  Software License, Version 1.0. (See accompanying file
0007 //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0008
0009 #ifndef BOOST_PROTO_FUNCTIONAL_RANGE_EMPTY_HPP_EAN_27_08_2012
0010 #define BOOST_PROTO_FUNCTIONAL_RANGE_EMPTY_HPP_EAN_27_08_2012
0011
0012 #include <boost/range/empty.hpp>
0013 #include <boost/proto/proto_fwd.hpp>
0014
0015 namespace boost { namespace proto { namespace functional
0016 {
0017
0018     // A PolymorphicFunctionObject that wraps boost::empty()
0019     struct empty
0020     {
0021         BOOST_PROTO_CALLABLE()
0022
0023         typedef bool result_type;
0024
0025         template<typename Rng>
0026         bool operator()(Rng const &rng) const
0027         {
0028             return boost::empty(rng);
0029         }
0030     };
0031
0032 }}}
0033
0034 #endif