ceph/src/boost/libs/log/include/boost/log/utility/functional/save_result.hpp

   1 /*
   2  *          Copyright Andrey Semashev 2007 - 2015.
   3  * Distributed under the Boost Software License, Version 1.0.
   4  *    (See accompanying file LICENSE_1_0.txt or copy at
   5  *          http://www.boost.org/LICENSE_1_0.txt)
   6  */
   7 /*!
   8  * \file   save_result.hpp
   9  * \author Andrey Semashev
  10  * \date   19.01.2013
  11  *
  12  * This header contains function object adapter that saves the result of the adopted function to an external variable.
  13  */
  14
  15 #ifndef BOOST_LOG_UTILITY_FUNCTIONAL_SAVE_RESULT_HPP_INCLUDED_
  16 #define BOOST_LOG_UTILITY_FUNCTIONAL_SAVE_RESULT_HPP_INCLUDED_
  17
  18 #include <boost/log/detail/config.hpp>
  19 #include <boost/log/detail/header.hpp>
  20
  21 #ifdef BOOST_HAS_PRAGMA_ONCE
  22 #pragma once
  23 #endif
  24
  25 namespace boost {
  26
  27 BOOST_LOG_OPEN_NAMESPACE
  28
  29 //! Function object wrapper for saving the adopted function object result
  30 template< typename FunT, typename AssigneeT >
  31 struct save_result_wrapper
  32 {
  33     typedef void result_type;
  34
  35     save_result_wrapper(FunT fun, AssigneeT& assignee) : m_fun(fun), m_assignee(assignee) {}
  36
  37     template< typename ArgT >
  38     result_type operator() (ArgT const& arg) const
  39     {
  40         m_assignee = m_fun(arg);
  41     }
  42
  43 private:
  44     FunT m_fun;
  45     AssigneeT& m_assignee;
  46 };
  47
  48 template< typename FunT, typename AssigneeT >
  49 BOOST_FORCEINLINE save_result_wrapper< FunT, AssigneeT > save_result(FunT const& fun, AssigneeT& assignee)
  50 {
  51     return save_result_wrapper< FunT, AssigneeT >(fun, assignee);
  52 }
  53
  54 BOOST_LOG_CLOSE_NAMESPACE // namespace log
  55
  56 } // namespace boost
  57
  58 #include <boost/log/detail/footer.hpp>
  59
  60 #endif // BOOST_LOG_UTILITY_FUNCTIONAL_SAVE_RESULT_HPP_INCLUDED_