ceph/src/boost/libs/log/include/boost/log/detail/is_ostream.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   is_ostream.hpp
   9  * \author Andrey Semashev
  10  * \date   05.07.2015
  11  *
  12  * \brief  This header is the Boost.Log library implementation, see the library documentation
  13  *         at http://www.boost.org/doc/libs/release/libs/log/doc/html/index.html. In this file
  14  *         internal configuration macros are defined.
  15  */
  16
  17 #ifndef BOOST_LOG_DETAIL_IS_OSTREAM_HPP_INCLUDED_
  18 #define BOOST_LOG_DETAIL_IS_OSTREAM_HPP_INCLUDED_
  19
  20 #include <iosfwd>
  21 #include <boost/type_traits/is_base_of.hpp>
  22 #include <boost/type_traits/has_left_shift.hpp>
  23 #include <boost/log/detail/config.hpp>
  24 #include <boost/log/utility/formatting_ostream_fwd.hpp>
  25 #include <boost/log/detail/header.hpp>
  26
  27 #ifdef BOOST_HAS_PRAGMA_ONCE
  28 #pragma once
  29 #endif
  30
  31 namespace boost {
  32
  33 BOOST_LOG_OPEN_NAMESPACE
  34
  35 namespace aux {
  36
  37 template< typename T >
  38 struct is_ostream
  39 {
  40     static BOOST_CONSTEXPR_OR_CONST bool value = is_base_of< std::ios_base, T >::value && has_left_shift< T, int >::value;
  41 };
  42
  43 template< typename CharT, typename TraitsT, typename AllocatorT >
  44 struct is_ostream< basic_formatting_ostream< CharT, TraitsT, AllocatorT > >
  45 {
  46     static BOOST_CONSTEXPR_OR_CONST bool value = true;
  47 };
  48
  49 } // namespace aux
  50
  51 BOOST_LOG_CLOSE_NAMESPACE // namespace log
  52
  53 } // namespace boost
  54
  55 #include <boost/log/detail/footer.hpp>
  56
  57 #endif // BOOST_LOG_DETAIL_IS_OSTREAM_HPP_INCLUDED_