ceph/src/boost/boost/log/utility/manipulators/auto_newline.hpp

   1 /*
   2  *             Copyright Andrey Semashev 2019.
   3  * Distributed under the Boost Software License, Version 1.0.
   4  *    (See accompanying file LICENSE_1_0.txt or copy at
   5  *          https://www.boost.org/LICENSE_1_0.txt)
   6  */
   7 /*!
   8  * \file   utility/manipulators/auto_newline.hpp
   9  * \author Andrey Semashev
  10  * \date   23.06.2019
  11  *
  12  * The header contains implementation of a stream manipulator for inserting a newline, unless there is already one inserted.
  13  */
  14
  15 #ifndef BOOST_LOG_UTILITY_MANIPULATORS_AUTO_NEWLINE_HPP_INCLUDED_
  16 #define BOOST_LOG_UTILITY_MANIPULATORS_AUTO_NEWLINE_HPP_INCLUDED_
  17
  18 #include <boost/log/detail/config.hpp>
  19 #include <boost/log/utility/formatting_ostream_fwd.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 /*!
  31  * Stream manipulator for inserting a newline character, unless the last character
  32  * inserted into the stream is already a newline.
  33  */
  34 struct auto_newline_manip {}
  35 BOOST_INLINE_VARIABLE const auto_newline = {};
  36
  37 /*!
  38  * Stream output operator for the \c auto_newline manipulator
  39  */
  40 template< typename CharT, typename TraitsT, typename AllocatorT >
  41 inline basic_formatting_ostream< CharT, TraitsT, AllocatorT >& operator<< (basic_formatting_ostream< CharT, TraitsT, AllocatorT >& strm, auto_newline_manip)
  42 {
  43     typedef basic_formatting_ostream< CharT, TraitsT, AllocatorT > stream_type;
  44     typedef typename stream_type::char_type char_type;
  45     typedef typename stream_type::string_type string_type;
  46     if (BOOST_LIKELY(strm.good()))
  47     {
  48         string_type* str = strm.rdbuf()->storage();
  49         if (BOOST_LIKELY(!!str))
  50         {
  51             strm.rdbuf()->pubsync();
  52             if (str->empty() || *str->rbegin() != static_cast< char_type >('\n'))
  53                 strm.rdbuf()->push_back(static_cast< char_type >('\n'));
  54         }
  55     }
  56
  57     return strm;
  58 }
  59
  60 BOOST_LOG_CLOSE_NAMESPACE // namespace log
  61
  62 } // namespace boost
  63
  64 #include <boost/log/detail/footer.hpp>
  65
  66 #endif // BOOST_LOG_UTILITY_MANIPULATORS_AUTO_NEWLINE_HPP_INCLUDED_