Chris@16: //-----------------------------------------------------------------------------
Chris@16: // boost blank.hpp header file
Chris@16: // See http://www.boost.org for updates, documentation, and revision history.
Chris@16: //-----------------------------------------------------------------------------
Chris@16: //
Chris@16: // Copyright (c) 2003
Chris@16: // Eric Friedman
Chris@16: //
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See
Chris@16: // accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_BLANK_HPP
Chris@16: #define BOOST_BLANK_HPP
Chris@16: 
Chris@16: #include "boost/blank_fwd.hpp"
Chris@16: 
Chris@16: #if !defined(BOOST_NO_IOSTREAM)
Chris@16: #include <iosfwd> // for std::basic_ostream forward declare
Chris@16: #include "boost/detail/templated_streams.hpp"
Chris@16: #endif // BOOST_NO_IOSTREAM
Chris@16: 
Chris@16: #include "boost/mpl/bool.hpp"
Chris@16: #include "boost/type_traits/is_empty.hpp"
Chris@16: #include "boost/type_traits/is_pod.hpp"
Chris@16: #include "boost/type_traits/is_stateless.hpp"
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16: struct blank
Chris@16: {
Chris@16: };
Chris@16: 
Chris@16: // type traits specializations
Chris@16: //
Chris@16: 
Chris@16: template <>
Chris@16: struct is_pod< blank >
Chris@16:     : mpl::true_
Chris@16: {
Chris@16: };
Chris@16: 
Chris@16: template <>
Chris@16: struct is_empty< blank >
Chris@16:     : mpl::true_
Chris@16: {
Chris@16: };
Chris@16: 
Chris@16: template <>
Chris@16: struct is_stateless< blank >
Chris@16:     : mpl::true_
Chris@16: {
Chris@16: };
Chris@16: 
Chris@16: // relational operators
Chris@16: //
Chris@16: 
Chris@16: inline bool operator==(const blank&, const blank&)
Chris@16: {
Chris@16:     return true;
Chris@16: }
Chris@16: 
Chris@16: inline bool operator<=(const blank&, const blank&)
Chris@16: {
Chris@16:     return true;
Chris@16: }
Chris@16: 
Chris@16: inline bool operator>=(const blank&, const blank&)
Chris@16: {
Chris@16:     return true;
Chris@16: }
Chris@16: 
Chris@16: inline bool operator!=(const blank&, const blank&)
Chris@16: {
Chris@16:     return false;
Chris@16: }
Chris@16: 
Chris@16: inline bool operator<(const blank&, const blank&)
Chris@16: {
Chris@16:     return false;
Chris@16: }
Chris@16: 
Chris@16: inline bool operator>(const blank&, const blank&)
Chris@16: {
Chris@16:     return false;
Chris@16: }
Chris@16: 
Chris@16: // streaming support
Chris@16: //
Chris@16: #if !defined(BOOST_NO_IOSTREAM)
Chris@16: 
Chris@16: BOOST_TEMPLATED_STREAM_TEMPLATE(E,T)
Chris@16: inline BOOST_TEMPLATED_STREAM(ostream, E,T)& operator<<(
Chris@16:       BOOST_TEMPLATED_STREAM(ostream, E,T)& out
Chris@16:     , const blank&
Chris@16:     )
Chris@16: {
Chris@16:     // (output nothing)
Chris@16:     return out;
Chris@16: }
Chris@16: 
Chris@16: #endif // BOOST_NO_IOSTREAM
Chris@16: 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #endif // BOOST_BLANK_HPP