49 lines
1.3 KiB
C++
49 lines
1.3 KiB
C++
/*
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* Copyright Andrey Semashev 2007 - 2015.
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* Distributed under the Boost Software License, Version 1.0.
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* (See accompanying file LICENSE_1_0.txt or copy at
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* http://www.boost.org/LICENSE_1_0.txt)
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*/
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/*!
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* \file fallback_policy_fwd.hpp
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* \author Andrey Semashev
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* \date 18.08.2012
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*
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* The header contains forward declaration of fallback policies when attribute value visitation or extraction fails.
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*/
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#ifndef BOOST_LOG_ATTRIBUTES_FALLBACK_POLICY_FWD_HPP_INCLUDED_
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#define BOOST_LOG_ATTRIBUTES_FALLBACK_POLICY_FWD_HPP_INCLUDED_
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#include <boost/log/detail/config.hpp>
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#ifdef BOOST_HAS_PRAGMA_ONCE
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#pragma once
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#endif
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namespace boost {
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BOOST_LOG_OPEN_NAMESPACE
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/*!
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* The \c fallback_to_none policy results in returning an empty value reference if the attribute value cannot be extracted.
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*/
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struct fallback_to_none;
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/*!
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* The \c fallback_to_throw policy results in throwing an exception if the attribute value cannot be extracted.
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*/
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struct fallback_to_throw;
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/*!
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* The \c fallback_to_default policy results in a default value if the attribute value cannot be extracted.
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*/
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template< typename DefaultT >
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struct fallback_to_default;
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BOOST_LOG_CLOSE_NAMESPACE // namespace log
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} // namespace boost
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#endif // BOOST_LOG_ATTRIBUTES_FALLBACK_POLICY_FWD_HPP_INCLUDED_
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