/Src/Dependencies/Boost/boost/spirit/home/support/unused.hpp
http://hadesmem.googlecode.com/ · C++ Header · 105 lines · 73 code · 16 blank · 16 comment · 0 complexity · d2f8c9a8b0da53f6f3ae8878a43282f3 MD5 · raw file
- /*=============================================================================
- Copyright (c) 2001-2011 Joel de Guzman
- Copyright (c) 2001-2011 Hartmut Kaiser
- 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)
- ==============================================================================*/
- #if !defined(BOOST_SPIRIT_UNUSED_APRIL_16_2006_0616PM)
- #define BOOST_SPIRIT_UNUSED_APRIL_16_2006_0616PM
- #if defined(_MSC_VER)
- #pragma once
- #endif
- #include <boost/config.hpp>
- #include <boost/mpl/bool.hpp>
- #if defined(BOOST_MSVC)
- # pragma warning(push)
- # pragma warning(disable: 4522) // multiple assignment operators specified warning
- #endif
- ///////////////////////////////////////////////////////////////////////////////
- namespace boost { namespace spirit
- {
- ///////////////////////////////////////////////////////////////////////////
- // We do not import fusion ::unused_type anymore to avoid boost::fusion
- // being turned into an associate namespace for boost::spirit, as this
- // interferes with ADL in unexpected ways. We rather copy the full
- // unused_type implementation from boost::fusion.
- ///////////////////////////////////////////////////////////////////////////
- struct unused_type
- {
- unused_type()
- {
- }
- template <typename T>
- unused_type(T const&)
- {
- }
- template <typename T>
- unused_type const&
- operator=(T const&) const
- {
- return *this;
- }
- template <typename T>
- unused_type&
- operator=(T const&)
- {
- return *this;
- }
- unused_type const&
- operator=(unused_type const&) const
- {
- return *this;
- }
- unused_type&
- operator=(unused_type const&)
- {
- return *this;
- }
- };
- unused_type const unused = unused_type();
- namespace detail
- {
- struct unused_only
- {
- unused_only(unused_type const&) {}
- };
- }
- template <typename Out>
- inline Out& operator<<(Out& out, detail::unused_only const&)
- {
- return out;
- }
- template <typename In>
- inline In& operator>>(In& in, unused_type&)
- {
- return in;
- }
- ///////////////////////////////////////////////////////////////////////////
- namespace traits
- {
- // We use this test to detect if the argument is not an unused_type
- template <typename T> struct not_is_unused : mpl::true_ {};
- template <> struct not_is_unused<unused_type> : mpl::false_ {};
- }
- }}
- #if defined(BOOST_MSVC)
- # pragma warning(pop)
- #endif
- #endif