| /* |
| * Copyright Andrey Semashev 2007 - 2015. |
| * 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) |
| */ |
| /*! |
| * \file fallback_policy_fwd.hpp |
| * \author Andrey Semashev |
| * \date 18.08.2012 |
| * |
| * The header contains forward declaration of fallback policies when attribute value visitation or extraction fails. |
| */ |
| |
| #ifndef BOOST_LOG_ATTRIBUTES_FALLBACK_POLICY_FWD_HPP_INCLUDED_ |
| #define BOOST_LOG_ATTRIBUTES_FALLBACK_POLICY_FWD_HPP_INCLUDED_ |
| |
| #include <boost/log/detail/config.hpp> |
| |
| #ifdef BOOST_HAS_PRAGMA_ONCE |
| #pragma once |
| #endif |
| |
| namespace boost { |
| |
| BOOST_LOG_OPEN_NAMESPACE |
| |
| /*! |
| * The \c fallback_to_none policy results in returning an empty value reference if the attribute value cannot be extracted. |
| */ |
| struct fallback_to_none; |
| |
| /*! |
| * The \c fallback_to_throw policy results in throwing an exception if the attribute value cannot be extracted. |
| */ |
| struct fallback_to_throw; |
| |
| /*! |
| * The \c fallback_to_default policy results in a default value if the attribute value cannot be extracted. |
| */ |
| template< typename DefaultT > |
| struct fallback_to_default; |
| |
| BOOST_LOG_CLOSE_NAMESPACE // namespace log |
| |
| } // namespace boost |
| |
| #endif // BOOST_LOG_ATTRIBUTES_FALLBACK_POLICY_FWD_HPP_INCLUDED_ |