ceph/src/boost/libs/log/include/boost/log/utility/functional/fun_ref.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   fun_ref.hpp
   9  * \author Andrey Semashev
  10  * \date   30.03.2008
  11  *
  12  * This header contains function object reference adapter. The adapter stores a reference to external
  13  * function object and forwards all calls to the referred function.
  14  */
  15
  16 #ifndef BOOST_LOG_UTILITY_FUNCTIONAL_FUN_REF_HPP_INCLUDED_
  17 #define BOOST_LOG_UTILITY_FUNCTIONAL_FUN_REF_HPP_INCLUDED_
  18
  19 #include <boost/log/detail/config.hpp>
  20 #include <boost/log/detail/header.hpp>
  21
  22 #ifdef BOOST_HAS_PRAGMA_ONCE
  23 #pragma once
  24 #endif
  25
  26 namespace boost {
  27
  28 BOOST_LOG_OPEN_NAMESPACE
  29
  30 //! Reference wrapper for function objects
  31 template< typename FunT >
  32 struct function_reference_wrapper
  33 {
  34     typedef typename FunT::result_type result_type;
  35
  36     explicit function_reference_wrapper(FunT& fun) : m_Fun(fun) {}
  37
  38     result_type operator() () const
  39     {
  40         return m_Fun();
  41     }
  42
  43 #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
  44     template< typename... ArgsT >
  45     result_type operator() (ArgsT const&... args) const
  46     {
  47         return m_Fun(args...);
  48     }
  49 #else
  50     template< typename T >
  51     result_type operator() (T const& arg) const
  52     {
  53         return m_Fun(arg);
  54     }
  55
  56     template< typename T1, typename T2 >
  57     result_type operator() (T1 const& arg1, T2 const& arg2) const
  58     {
  59         return m_Fun(arg1, arg2);
  60     }
  61 #endif
  62
  63 private:
  64     FunT& m_Fun;
  65 };
  66
  67 template< typename FunT >
  68 BOOST_FORCEINLINE function_reference_wrapper< FunT > fun_ref(FunT& fun)
  69 {
  70     return function_reference_wrapper< FunT >(fun);
  71 }
  72
  73 BOOST_LOG_CLOSE_NAMESPACE // namespace log
  74
  75 } // namespace boost
  76
  77 #include <boost/log/detail/footer.hpp>
  78
  79 #endif // BOOST_LOG_UTILITY_FUNCTIONAL_FUN_REF_HPP_INCLUDED_