log/detail/is_ostream.hpp

0001 /*
0002  *          Copyright Andrey Semashev 2007 - 2015.
0003  * Distributed under the Boost Software License, Version 1.0.
0004  *    (See accompanying file LICENSE_1_0.txt or copy at
0005  *          http://www.boost.org/LICENSE_1_0.txt)
0006  */
0007 /*!
0008  * \file   is_ostream.hpp
0009  * \author Andrey Semashev
0010  * \date   05.07.2015
0011  *
0012  * \brief  This header is the Boost.Log library implementation, see the library documentation
0013  *         at http://www.boost.org/doc/libs/release/libs/log/doc/html/index.html. In this file
0014  *         internal configuration macros are defined.
0015  */
0016
0017 #ifndef BOOST_LOG_DETAIL_IS_OSTREAM_HPP_INCLUDED_
0018 #define BOOST_LOG_DETAIL_IS_OSTREAM_HPP_INCLUDED_
0019
0020 #include <iosfwd>
0021 #include <boost/type_traits/is_base_of.hpp>
0022 #include <boost/type_traits/has_left_shift.hpp>
0023 #include <boost/log/detail/config.hpp>
0024 #include <boost/log/utility/formatting_ostream_fwd.hpp>
0025 #include <boost/log/detail/header.hpp>
0026
0027 #ifdef BOOST_HAS_PRAGMA_ONCE
0028 #pragma once
0029 #endif
0030
0031 namespace boost {
0032
0033 BOOST_LOG_OPEN_NAMESPACE
0034
0035 namespace aux {
0036
0037 template< typename T >
0038 struct is_ostream
0039 {
0040     static BOOST_CONSTEXPR_OR_CONST bool value = is_base_of< std::ios_base, T >::value && has_left_shift< T, int >::value;
0041 };
0042
0043 template< typename CharT, typename TraitsT, typename AllocatorT >
0044 struct is_ostream< basic_formatting_ostream< CharT, TraitsT, AllocatorT > >
0045 {
0046     static BOOST_CONSTEXPR_OR_CONST bool value = true;
0047 };
0048
0049 } // namespace aux
0050
0051 BOOST_LOG_CLOSE_NAMESPACE // namespace log
0052
0053 } // namespace boost
0054
0055 #include <boost/log/detail/footer.hpp>
0056
0057 #endif // BOOST_LOG_DETAIL_IS_OSTREAM_HPP_INCLUDED_