text: /*
   *          Copyright Andrey Semashev 2007 - 2015.
   * Distributed under the Boost Software License, Version 1.0.
   *    (See accompanying file LICENSE_1_0.txt or copy at
   *          http://www.boost.org/LICENSE_1_0.txt)
   */
  /*!
   * \file   formatting_ostream.hpp
   * \author Andrey Semashev
   * \date   11.07.2012
   *
   * The header contains implementation of a string stream used for log record formatting.
   */
  
  #ifndef BOOST_LOG_UTILITY_FORMATTING_OSTREAM_HPP_INCLUDED_
  #define BOOST_LOG_UTILITY_FORMATTING_OSTREAM_HPP_INCLUDED_
  
  #include <ostream>
  #include <string>
  #include <memory>
  #include <locale>
  #include <boost/core/explicit_operator_bool.hpp>
  #include <boost/utility/string_view_fwd.hpp>
  #include <boost/type_traits/remove_cv.hpp>
  #include <boost/log/detail/config.hpp>
  #include <boost/log/detail/attachable_sstream_buf.hpp>
  #include <boost/log/detail/code_conversion.hpp>
  #include <boost/log/utility/string_literal_fwd.hpp>
  #include <boost/log/utility/formatting_ostream_fwd.hpp>
  #include <boost/log/detail/header.hpp>
  
  #ifdef BOOST_HAS_PRAGMA_ONCE
  #pragma once
  #endif
  
  namespace boost {
  
  // Duplicate from boost/utility/string_ref_fwd.hpp, which currently does not have this forward declaration
  template<typename charT, typename traits = std::char_traits<charT> > class basic_string_ref;
  
  BOOST_LOG_OPEN_NAMESPACE
  
  namespace aux {
  
  template< typename T, typename R >
  struct enable_if_streamable_char_type {};
  template< typename R >
  struct enable_if_streamable_char_type< char, R > { typedef R type; };
  template< typename R >
  struct enable_if_streamable_char_type< wchar_t, R > { typedef R type; };
  #if !defined(BOOST_LOG_NO_CXX11_CODECVT_FACETS)
  #if !defined(BOOST_NO_CXX11_CHAR16_T)
  template< typename R >
  struct enable_if_streamable_char_type< char16_t, R > { typedef R type; };
  #endif
  #if !defined(BOOST_NO_CXX11_CHAR32_T)
  template< typename R >
  struct enable_if_streamable_char_type< char32_t, R > { typedef R type; };
  #endif
  #endif
  
  template< typename StreamT, typename R >
  struct enable_if_formatting_ostream {};
  template< typename CharT, typename TraitsT, typename AllocatorT, typename R >
  struct enable_if_formatting_ostream< basic_formatting_ostream< CharT, TraitsT, AllocatorT >, R > { typedef R type; };
  
  } // namespace aux
  
  /*!
   * \brief Stream wrapper for log records formatting.
   *
   * This stream wrapper is used by the library for log record formatting. It implements the standard string stream interface
   * with a few differences:
   *
   * \li It does not derive from standard types <tt>std::basic_ostream</tt>, <tt>std::basic_ios</tt> and <tt>std::ios_base</tt>,
   *     although it tries to implement their interfaces closely. There are a few small differences, mostly regarding <tt>rdbuf</tt>
   *     and <tt>str</tt> signatures, as well as the supported insertion operator overloads. The actual wrapped stream can be accessed
   *     through the <tt>stream</tt> methods.
   * \li By default, \c bool values are formatted using alphabetical representation rather than numeric.
   * \li The stream supports writing strings of character types different from the stream character type. The stream will perform
   *     character code conversion as needed using the imbued locale.
   * \li The stream operates on an external string object rather than on the embedded one. The string can be attached or detached
   *     from the stream dynamically.
   *
   * Although <tt>basic_formatting_ostream</tt> does not derive from <tt>std::basic_ostream</tt>, users are not required to add
   * special overloads of \c operator<< for it since the stream will by default reuse the operators for <tt>std::basic_ostream</tt>.
   * However, one can define special overloads of \c operator<< for <tt>basic_formatting_ostream</tt> if a certain type needs
   * special formatting when output to log.
   */
  template< typename CharT, typename TraitsT, typename AllocatorT >
  class basic_formatting_ostream
  {
  public:
      //! Character type
      typedef CharT char_type;
      //! Character traits
      typedef TraitsT traits_type;
      //! Memory allocator
      typedef AllocatorT allocator_type;
      //! Stream buffer type
      typedef boost::log::aux::basic_ostringstreambuf< char_type, traits_type, allocator_type > streambuf_type;
      //! Target string type
      typedef typename streambuf_type::string_type string_type;
  
      //! Stream type
      typedef std::basic_ostream< char_type, traits_type > ostream_type;
      //! Stream position type
      typedef typename ostream_type::pos_type pos_type;
      //! Stream offset type
      typedef typename ostream_type::off_type off_type;
      //! Integer type for characters
      typedef typename ostream_type::int_type int_type;
  
      typedef typename ostream_type::failure failure;
      typedef typename ostream_type::fmtflags fmtflags;
      typedef typename ostream_type::iostate iostate;
      typedef typename ostream_type::openmode openmode;
      typedef typename ostream_type::seekdir seekdir;
      typedef typename ostream_type::Init Init;
  
      typedef typename ostream_type::event event;
      typedef typename ostream_type::event_callback event_callback;
  
      class sentry :
          public ostream_type::sentry
      {
          typedef typename ostream_type::sentry base_type;
  
      public:
          explicit sentry(basic_formatting_ostream& strm) : base_type(strm.stream())
          {
          }
  
          // A workaround for Solaris Studio 12.4 compiler, see: https://svn.boost.org/trac/boost/ticket/11545
          BOOST_EXPLICIT_OPERATOR_BOOL()
          bool operator! () const { return !static_cast< base_type const& >(*this); }
  
          BOOST_DELETED_FUNCTION(sentry(sentry const&))
          BOOST_DELETED_FUNCTION(sentry& operator= (sentry const&))
      };
  
  private:
      //  Function types
      typedef std::ios_base& (*ios_base_manip)(std::ios_base&);
      typedef std::basic_ios< char_type, traits_type >& (*basic_ios_manip)(std::basic_ios< char_type, traits_type >&);
      typedef ostream_type& (*stream_manip)(ostream_type&);
  
  public:
      static BOOST_CONSTEXPR_OR_CONST fmtflags boolalpha = ostream_type::boolalpha;
      static BOOST_CONSTEXPR_OR_CONST fmtflags dec = ostream_type::dec;
      static BOOST_CONSTEXPR_OR_CONST fmtflags fixed = ostream_type::fixed;
      static BOOST_CONSTEXPR_OR_CONST fmtflags hex = ostream_type::hex;
      static BOOST_CONSTEXPR_OR_CONST fmtflags internal = ostream_type::internal;
      static BOOST_CONSTEXPR_OR_CONST fmtflags left = ostream_type::left;
      static BOOST_CONSTEXPR_OR_CONST fmtflags oct = ostream_type::oct;
      static BOOST_CONSTEXPR_OR_CONST fmtflags right = ostream_type::right;
      static BOOST_CONSTEXPR_OR_CONST fmtflags scientific = ostream_type::scientific;
      static BOOST_CONSTEXPR_OR_CONST fmtflags showbase = ostream_type::showbase;
      static BOOST_CONSTEXPR_OR_CONST fmtflags showpoint = ostream_type::showpoint;
      static BOOST_CONSTEXPR_OR_CONST fmtflags skipws = ostream_type::skipws;
      static BOOST_CONSTEXPR_OR_CONST fmtflags unitbuf = ostream_type::unitbuf;
      static BOOST_CONSTEXPR_OR_CONST fmtflags uppercase = ostream_type::uppercase;
      static BOOST_CONSTEXPR_OR_CONST fmtflags adjustfield = ostream_type::adjustfield;
      static BOOST_CONSTEXPR_OR_CONST fmtflags basefield = ostream_type::basefield;
      static BOOST_CONSTEXPR_OR_CONST fmtflags floatfield = ostream_type::floatfield;
  
      static BOOST_CONSTEXPR_OR_CONST iostate badbit = ostream_type::badbit;
      static BOOST_CONSTEXPR_OR_CONST iostate eofbit = ostream_type::eofbit;
      static BOOST_CONSTEXPR_OR_CONST iostate failbit = ostream_type::failbit;
      static BOOST_CONSTEXPR_OR_CONST iostate goodbit = ostream_type::goodbit;
  
      static BOOST_CONSTEXPR_OR_CONST openmode app = ostream_type::app;
      static BOOST_CONSTEXPR_OR_CONST openmode ate = ostream_type::ate;
      static BOOST_CONSTEXPR_OR_CONST openmode binary = ostream_type::binary;
      static BOOST_CONSTEXPR_OR_CONST openmode in = ostream_type::in;
      static BOOST_CONSTEXPR_OR_CONST openmode out = ostream_type::out;
      static BOOST_CONSTEXPR_OR_CONST openmode trunc = ostream_type::trunc;
  
      static BOOST_CONSTEXPR_OR_CONST seekdir beg = ostream_type::beg;
      static BOOST_CONSTEXPR_OR_CONST seekdir cur = ostream_type::cur;
      static BOOST_CONSTEXPR_OR_CONST seekdir end = ostream_type::end;
  
      static BOOST_CONSTEXPR_OR_CONST event erase_event = ostream_type::erase_event;
      static BOOST_CONSTEXPR_OR_CONST event imbue_event = ostream_type::imbue_event;
      static BOOST_CONSTEXPR_OR_CONST event copyfmt_event = ostream_type::copyfmt_event;
  
  private:
      mutable streambuf_type m_streambuf;
      ostream_type m_stream;
  
  public:
      /*!
       * Default constructor. Creates an empty record that is equivalent to the invalid record handle.
       * The stream capability is not available after construction.
       *
       * \post <tt>!*this == true</tt>
       */
      basic_formatting_ostream() : m_stream(&m_streambuf)
      {
          init_stream();
      }
  
      /*!
       * Initializing constructor. Attaches the string to the constructed stream.
       * The string will be used to store the formatted characters.
       *
       * \post <tt>!*this == false</tt>
       * \param str The string buffer to attach.
       */
      explicit basic_formatting_ostream(string_type& str) :
          m_streambuf(str),
          m_stream(&m_streambuf)
      {
          init_stream();
      }
  
      /*!
       * Destructor. Destroys the record, releases any sinks and attribute values that were involved in processing this record.
       */
      ~basic_formatting_ostream()
      {
          if (m_streambuf.storage())
              flush();
      }
  
      /*!
       * Attaches the stream to the string. The string will be used to store the formatted characters.
       *
       * \param str The string buffer to attach.
       */
      void attach(string_type& str)
      {
          m_streambuf.attach(str);
          m_stream.clear(ostream_type::goodbit);
      }
      /*!
       * Detaches the stream from the string. Any buffered data is flushed to the string.
       */
      void detach()
      {
          m_streambuf.detach();
          m_stream.clear(ostream_type::badbit);
      }
  
      /*!
       * \returns Reference to the attached string. The string must be attached before calling this method.
       */
      string_type const& str() const
      {
          string_type* storage = m_streambuf.storage();
          BOOST_ASSERT(storage != NULL);
  
          m_streambuf.pubsync();
  
          return *storage;
      }
  
      /*!
       * \returns Reference to the wrapped stream
       */
      ostream_type& stream() { return m_stream; }
  
      /*!
       * \returns Reference to the wrapped stream
       */
      ostream_type const& stream() const { return m_stream; }
  
      // std::ios_base method forwarders
      fmtflags flags() const { return m_stream.flags(); }
      fmtflags flags(fmtflags f) { return m_stream.flags(f); }
      fmtflags setf(fmtflags f) { return m_stream.setf(f); }
      fmtflags setf(fmtflags f, fmtflags mask) { return m_stream.setf(f, mask); }
      void unsetf(fmtflags f) { m_stream.unsetf(f); }
  
      std::streamsize precision() const { return m_stream.precision(); }
      std::streamsize precision(std::streamsize p) { return m_stream.precision(p); }
  
      std::streamsize width() const { return m_stream.width(); }
      std::streamsize width(std::streamsize w) { return m_stream.width(w); }
  
      std::locale getloc() const { return m_stream.getloc(); }
      std::locale imbue(std::locale const& loc) { return m_stream.imbue(loc); }
  
      static int xalloc() { return ostream_type::xalloc(); }
      long& iword(int index) { return m_stream.iword(index); }
      void*& pword(int index) { return m_stream.pword(index); }
  
      void register_callback(event_callback fn, int index) { m_stream.register_callback(fn, index); }
  
      static bool sync_with_stdio(bool sync = true) { return ostream_type::sync_with_stdio(sync); }
  
      // std::basic_ios method forwarders
      BOOST_EXPLICIT_OPERATOR_BOOL()
      bool operator! () const { return !m_stream; }
  
      iostate rdstate() const { return m_stream.rdstate(); }
      void clear(iostate state = goodbit) { m_stream.clear(state); }
      void setstate(iostate state) { m_stream.setstate(state); }
      bool good() const { return m_stream.good(); }
      bool eof() const { return m_stream.eof(); }
      bool fail() const { return m_stream.fail(); }
      bool bad() const { return m_stream.bad(); }
  
      iostate exceptions() const { return m_stream.exceptions(); }
      void exceptions(iostate s) { m_stream.exceptions(s); }
  
      ostream_type* tie() const { return m_stream.tie(); }
      ostream_type* tie(ostream_type* strm) { return m_stream.tie(strm); }
  
      streambuf_type* rdbuf() const { return &m_streambuf; }
  
      basic_formatting_ostream& copyfmt(std::basic_ios< char_type, traits_type >& rhs)
      {
          m_stream.copyfmt(rhs);
          return *this;
      }
      basic_formatting_ostream& copyfmt(basic_formatting_ostream& rhs)
      {
          m_stream.copyfmt(rhs.stream());
          return *this;
      }
  
      char_type fill() const { return m_stream.fill(); }
      char_type fill(char_type ch) { return m_stream.fill(ch); }
  
      char narrow(char_type ch, char def) const { return m_stream.narrow(ch, def); }
      char_type widen(char ch) const { return m_stream.widen(ch); }
  
      // std::basic_ostream method forwarders
      basic_formatting_ostream& flush()
      {
          m_stream.flush();
          return *this;
      }
  
      pos_type tellp() { return m_stream.tellp(); }
      basic_formatting_ostream& seekp(pos_type pos)
      {
          m_stream.seekp(pos);
          return *this;
      }
      basic_formatting_ostream& seekp(off_type off, std::ios_base::seekdir dir)
      {
          m_stream.seekp(off, dir);
          return *this;
      }
  
      basic_formatting_ostream& put(char_type c)
      {
          m_stream.put(c);
          return *this;
      }
  
      template< typename OtherCharT >
      typename aux::enable_if_streamable_char_type< OtherCharT, basic_formatting_ostream& >::type
      put(OtherCharT c)
      {
          write(&c, 1);
          return *this;
      }
  
      basic_formatting_ostream& write(const char_type* p, std::streamsize size)
      {
          m_stream.write(p, size);
          return *this;
      }
  
      template< typename OtherCharT >
      typename aux::enable_if_streamable_char_type< OtherCharT, basic_formatting_ostream& >::type
      write(const OtherCharT* p, std::streamsize size)
      {
          sentry guard(*this);
          if (!!guard)
          {
              m_stream.flush();
  
              string_type* storage = m_streambuf.storage();
              aux::code_convert(p, static_cast< std::size_t >(size), *storage, m_stream.getloc());
          }
  
          return *this;
      }
  
      basic_formatting_ostream& operator<< (ios_base_manip manip)
      {
          m_stream << manip;
          return *this;
      }
      basic_formatting_ostream& operator<< (basic_ios_manip manip)
      {
          m_stream << manip;
          return *this;
      }
      basic_formatting_ostream& operator<< (stream_manip manip)
      {
          m_stream << manip;
          return *this;
      }
  
      basic_formatting_ostream& operator<< (char c)
      {
          return this->formatted_write(&c, 1);
      }
      basic_formatting_ostream& operator<< (const char* p)
      {
          return this->formatted_write(p, static_cast< std::streamsize >(std::char_traits< char >::length(p)));
      }
  
      // When no native character type is supported, the following overloads are disabled as they have ambiguous meaning.
      // Use basic_string_view or basic_string to explicitly indicate that the data is a string.
  #if !defined(BOOST_NO_INTRINSIC_WCHAR_T)
      basic_formatting_ostream& operator<< (wchar_t c)
      {
          return this->formatted_write(&c, 1);
      }
      basic_formatting_ostream& operator<< (const wchar_t* p)
      {
          return this->formatted_write(p, static_cast< std::streamsize >(std::char_traits< wchar_t >::length(p)));
      }
  #endif
  #if !defined(BOOST_LOG_NO_CXX11_CODECVT_FACETS)
  #if !defined(BOOST_NO_CXX11_CHAR16_T)
      basic_formatting_ostream& operator<< (char16_t c)
      {
          return this->formatted_write(&c, 1);
      }
      basic_formatting_ostream& operator<< (const char16_t* p)
      {
          return this->formatted_write(p, static_cast< std::streamsize >(std::char_traits< char16_t >::length(p)));
      }
  #endif
  #if !defined(BOOST_NO_CXX11_CHAR32_T)
      basic_formatting_ostream& operator<< (char32_t c)
      {
          return this->formatted_write(&c, 1);
      }
      basic_formatting_ostream& operator<< (const char32_t* p)
      {
          return this->formatted_write(p, static_cast< std::streamsize >(std::char_traits< char32_t >::length(p)));
      }
  #endif
  #endif
  
      basic_formatting_ostream& operator<< (bool value)
      {
          m_stream << value;
          return *this;
      }
      basic_formatting_ostream& operator<< (signed char value)
      {
          m_stream << value;
          return *this;
      }
      basic_formatting_ostream& operator<< (unsigned char value)
      {
          m_stream << value;
          return *this;
      }
      basic_formatting_ostream& operator<< (short value)
      {
          m_stream << value;
          return *this;
      }
      basic_formatting_ostream& operator<< (unsigned short value)
      {
          m_stream << value;
          return *this;
      }
      basic_formatting_ostream& operator<< (int value)
      {
          m_stream << value;
          return *this;
      }
      basic_formatting_ostream& operator<< (unsigned int value)
      {
          m_stream << value;
          return *this;
      }
      basic_formatting_ostream& operator<< (long value)
      {
          m_stream << value;
          return *this;
      }
      basic_formatting_ostream& operator<< (unsigned long value)
      {
          m_stream << value;
          return *this;
      }
  #if !defined(BOOST_NO_LONG_LONG)
      basic_formatting_ostream& operator<< (long long value)
      {
          m_stream << value;
          return *this;
      }
      basic_formatting_ostream& operator<< (unsigned long long value)
      {
          m_stream << value;
          return *this;
      }
  #endif
  
      basic_formatting_ostream& operator<< (float value)
      {
          m_stream << value;
          return *this;
      }
      basic_formatting_ostream& operator<< (double value)
      {
          m_stream << value;
          return *this;
      }
      basic_formatting_ostream& operator<< (long double value)
      {
          m_stream << value;
          return *this;
      }
  
      basic_formatting_ostream& operator<< (const void* value)
      {
          m_stream << value;
          return *this;
      }
  
      basic_formatting_ostream& operator<< (std::basic_streambuf< char_type, traits_type >* buf)
      {
          m_stream << buf;
          return *this;
      }
  
      template< typename OtherCharT, typename OtherTraitsT, typename OtherAllocatorT >
      friend typename aux::enable_if_streamable_char_type< OtherCharT, basic_formatting_ostream& >::type
      operator<< (basic_formatting_ostream& strm, std::basic_string< OtherCharT, OtherTraitsT, OtherAllocatorT > const& str)
      {
          return strm.formatted_write(str.c_str(), static_cast< std::streamsize >(str.size()));
      }
  
      template< typename OtherCharT, typename OtherTraitsT >
      friend typename aux::enable_if_streamable_char_type< OtherCharT, basic_formatting_ostream& >::type
      operator<< (basic_formatting_ostream& strm, basic_string_literal< OtherCharT, OtherTraitsT > const& str)
      {
          return strm.formatted_write(str.c_str(), static_cast< std::streamsize >(str.size()));
      }
  
      template< typename OtherCharT, typename OtherTraitsT >
      friend typename aux::enable_if_streamable_char_type< OtherCharT, basic_formatting_ostream& >::type
      operator<< (basic_formatting_ostream& strm, basic_string_view< OtherCharT, OtherTraitsT > const& str)
      {
          return strm.formatted_write(str.data(), static_cast< std::streamsize >(str.size()));
      }
  
      // Deprecated overload
      template< typename OtherCharT, typename OtherTraitsT >
      friend typename aux::enable_if_streamable_char_type< OtherCharT, basic_formatting_ostream& >::type
      operator<< (basic_formatting_ostream& strm, basic_string_ref< OtherCharT, OtherTraitsT > const& str)
      {
          return strm.formatted_write(str.data(), static_cast< std::streamsize >(str.size()));
      }
  
      template< typename OtherCharT, typename OtherTraitsT, typename OtherAllocatorT >
      friend typename aux::enable_if_streamable_char_type< OtherCharT, basic_formatting_ostream& >::type
      operator<< (basic_formatting_ostream& strm, std::basic_string< OtherCharT, OtherTraitsT, OtherAllocatorT >& str)
      {
          return strm.formatted_write(str.c_str(), static_cast< std::streamsize >(str.size()));
      }
  
      template< typename OtherCharT, typename OtherTraitsT >
      friend typename aux::enable_if_streamable_char_type< OtherCharT, basic_formatting_ostream& >::type
      operator<< (basic_formatting_ostream& strm, basic_string_literal< OtherCharT, OtherTraitsT >& str)
      {
          return strm.formatted_write(str.c_str(), static_cast< std::streamsize >(str.size()));
      }
  
      template< typename OtherCharT, typename OtherTraitsT >
      friend typename aux::enable_if_streamable_char_type< OtherCharT, basic_formatting_ostream& >::type
      operator<< (basic_formatting_ostream& strm, basic_string_view< OtherCharT, OtherTraitsT >& str)
      {
          return strm.formatted_write(str.data(), static_cast< std::streamsize >(str.size()));
      }
  
      // Deprecated overload
      template< typename OtherCharT, typename OtherTraitsT >
      friend typename aux::enable_if_streamable_char_type< OtherCharT, basic_formatting_ostream& >::type
      operator<< (basic_formatting_ostream& strm, basic_string_ref< OtherCharT, OtherTraitsT >& str)
      {
          return strm.formatted_write(str.data(), static_cast< std::streamsize >(str.size()));
      }
  
  #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
      template< typename OtherCharT, typename OtherTraitsT, typename OtherAllocatorT >
      friend typename aux::enable_if_streamable_char_type< OtherCharT, basic_formatting_ostream& >::type
      operator<< (basic_formatting_ostream&& strm, std::basic_string< OtherCharT, OtherTraitsT, OtherAllocatorT > const& str)
      {
          return strm.formatted_write(str.c_str(), static_cast< std::streamsize >(str.size()));
      }
  
      template< typename OtherCharT, typename OtherTraitsT >
      friend typename aux::enable_if_streamable_char_type< OtherCharT, basic_formatting_ostream& >::type
      operator<< (basic_formatting_ostream&& strm, basic_string_literal< OtherCharT, OtherTraitsT > const& str)
      {
          return strm.formatted_write(str.c_str(), static_cast< std::streamsize >(str.size()));
      }
  
      template< typename OtherCharT, typename OtherTraitsT >
      friend typename aux::enable_if_streamable_char_type< OtherCharT, basic_formatting_ostream& >::type
      operator<< (basic_formatting_ostream&& strm, basic_string_view< OtherCharT, OtherTraitsT > const& str)
      {
          return strm.formatted_write(str.data(), static_cast< std::streamsize >(str.size()));
      }
  
      // Deprecated overload
      template< typename OtherCharT, typename OtherTraitsT >
      friend typename aux::enable_if_streamable_char_type< OtherCharT, basic_formatting_ostream& >::type
      operator<< (basic_formatting_ostream&& strm, basic_string_ref< OtherCharT, OtherTraitsT > const& str)
      {
          return strm.formatted_write(str.data(), static_cast< std::streamsize >(str.size()));
      }
  
      template< typename OtherCharT, typename OtherTraitsT, typename OtherAllocatorT >
      friend typename aux::enable_if_streamable_char_type< OtherCharT, basic_formatting_ostream& >::type
      operator<< (basic_formatting_ostream&& strm, std::basic_string< OtherCharT, OtherTraitsT, OtherAllocatorT >& str)
      {
          return strm.formatted_write(str.c_str(), static_cast< std::streamsize >(str.size()));
      }
  
      template< typename OtherCharT, typename OtherTraitsT >
      friend typename aux::enable_if_streamable_char_type< OtherCharT, basic_formatting_ostream& >::type
      operator<< (basic_formatting_ostream&& strm, basic_string_literal< OtherCharT, OtherTraitsT >& str)
      {
          return strm.formatted_write(str.c_str(), static_cast< std::streamsize >(str.size()));
      }
  
      template< typename OtherCharT, typename OtherTraitsT >
      friend typename aux::enable_if_streamable_char_type< OtherCharT, basic_formatting_ostream& >::type
      operator<< (basic_formatting_ostream&& strm, basic_string_view< OtherCharT, OtherTraitsT >& str)
      {
          return strm.formatted_write(str.data(), static_cast< std::streamsize >(str.size()));
      }
  
      // Deprecated overload
      template< typename OtherCharT, typename OtherTraitsT >
      friend typename aux::enable_if_streamable_char_type< OtherCharT, basic_formatting_ostream& >::type
      operator<< (basic_formatting_ostream&& strm, basic_string_ref< OtherCharT, OtherTraitsT >& str)
      {
          return strm.formatted_write(str.data(), static_cast< std::streamsize >(str.size()));
      }
  #endif
  
  private:
      void init_stream()
      {
          m_stream.clear(m_streambuf.storage() ? ostream_type::goodbit : ostream_type::badbit);
          m_stream.flags
          (
              ostream_type::dec |
              ostream_type::skipws |
              ostream_type::boolalpha // this differs from the default stream flags but makes logs look better
          );
          m_stream.width(0);
          m_stream.precision(6);
          m_stream.fill(static_cast< char_type >(' '));
      }
  
      basic_formatting_ostream& formatted_write(const char_type* p, std::streamsize size)
      {
          sentry guard(*this);
          if (!!guard)
          {
              m_stream.flush();
  
              if (m_stream.width() <= size)
                  m_streambuf.storage()->append(p, static_cast< std::size_t >(size));
              else
                  this->aligned_write(p, size);
  
              m_stream.width(0);
          }
  
          return *this;
      }
  
      template< typename OtherCharT >
      basic_formatting_ostream& formatted_write(const OtherCharT* p, std::streamsize size)
      {
          sentry guard(*this);
          if (!!guard)
          {
              m_stream.flush();
  
              if (m_stream.width() <= size)
                  aux::code_convert(p, static_cast< std::size_t >(size), *m_streambuf.storage(), m_stream.getloc());
              else
                  this->aligned_write(p, size);
  
              m_stream.width(0);
          }
  
          return *this;
      }
  
      void aligned_write(const char_type* p, std::streamsize size);
  
      template< typename OtherCharT >
      void aligned_write(const OtherCharT* p, std::streamsize size);
  
      //! Copy constructor (closed)
      BOOST_DELETED_FUNCTION(basic_formatting_ostream(basic_formatting_ostream const& that))
      //! Assignment (closed)
      BOOST_DELETED_FUNCTION(basic_formatting_ostream& operator= (basic_formatting_ostream const& that))
  };
  
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::fmtflags basic_formatting_ostream< CharT, TraitsT, AllocatorT >::boolalpha;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::fmtflags basic_formatting_ostream< CharT, TraitsT, AllocatorT >::dec;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::fmtflags basic_formatting_ostream< CharT, TraitsT, AllocatorT >::fixed;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::fmtflags basic_formatting_ostream< CharT, TraitsT, AllocatorT >::hex;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::fmtflags basic_formatting_ostream< CharT, TraitsT, AllocatorT >::internal;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::fmtflags basic_formatting_ostream< CharT, TraitsT, AllocatorT >::left;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::fmtflags basic_formatting_ostream< CharT, TraitsT, AllocatorT >::oct;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::fmtflags basic_formatting_ostream< CharT, TraitsT, AllocatorT >::right;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::fmtflags basic_formatting_ostream< CharT, TraitsT, AllocatorT >::scientific;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::fmtflags basic_formatting_ostream< CharT, TraitsT, AllocatorT >::showbase;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::fmtflags basic_formatting_ostream< CharT, TraitsT, AllocatorT >::showpoint;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::fmtflags basic_formatting_ostream< CharT, TraitsT, AllocatorT >::skipws;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::fmtflags basic_formatting_ostream< CharT, TraitsT, AllocatorT >::unitbuf;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::fmtflags basic_formatting_ostream< CharT, TraitsT, AllocatorT >::uppercase;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::fmtflags basic_formatting_ostream< CharT, TraitsT, AllocatorT >::adjustfield;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::fmtflags basic_formatting_ostream< CharT, TraitsT, AllocatorT >::basefield;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::fmtflags basic_formatting_ostream< CharT, TraitsT, AllocatorT >::floatfield;
  
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::iostate basic_formatting_ostream< CharT, TraitsT, AllocatorT >::badbit;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::iostate basic_formatting_ostream< CharT, TraitsT, AllocatorT >::eofbit;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::iostate basic_formatting_ostream< CharT, TraitsT, AllocatorT >::failbit;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::iostate basic_formatting_ostream< CharT, TraitsT, AllocatorT >::goodbit;
  
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::openmode basic_formatting_ostream< CharT, TraitsT, AllocatorT >::app;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::openmode basic_formatting_ostream< CharT, TraitsT, AllocatorT >::ate;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::openmode basic_formatting_ostream< CharT, TraitsT, AllocatorT >::binary;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::openmode basic_formatting_ostream< CharT, TraitsT, AllocatorT >::in;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::openmode basic_formatting_ostream< CharT, TraitsT, AllocatorT >::out;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::openmode basic_formatting_ostream< CharT, TraitsT, AllocatorT >::trunc;
  
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::seekdir basic_formatting_ostream< CharT, TraitsT, AllocatorT >::beg;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::seekdir basic_formatting_ostream< CharT, TraitsT, AllocatorT >::cur;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::seekdir basic_formatting_ostream< CharT, TraitsT, AllocatorT >::end;
  
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::event basic_formatting_ostream< CharT, TraitsT, AllocatorT >::erase_event;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::event basic_formatting_ostream< CharT, TraitsT, AllocatorT >::imbue_event;
  template< typename CharT, typename TraitsT, typename AllocatorT >
  BOOST_CONSTEXPR_OR_CONST typename basic_formatting_ostream< CharT, TraitsT, AllocatorT >::event basic_formatting_ostream< CharT, TraitsT, AllocatorT >::copyfmt_event;
  
  template< typename CharT, typename TraitsT, typename AllocatorT >
  void basic_formatting_ostream< CharT, TraitsT, AllocatorT >::aligned_write(const char_type* p, std::streamsize size)
  {
      string_type* const storage = m_streambuf.storage();
      typename string_type::size_type const alignment_size =
          static_cast< typename string_type::size_type >(m_stream.width() - size);
      const bool align_left = (m_stream.flags() & ostream_type::adjustfield) == ostream_type::left;
      if (align_left)
      {
          storage->append(p, static_cast< std::size_t >(size));
          storage->append(alignment_size, m_stream.fill());
      }
      else
      {
          storage->append(alignment_size, m_stream.fill());
          storage->append(p, static_cast< std::size_t >(size));
      }
  }
  
  template< typename CharT, typename TraitsT, typename AllocatorT >
  template< typename OtherCharT >
  void basic_formatting_ostream< CharT, TraitsT, AllocatorT >::aligned_write(const OtherCharT* p, std::streamsize size)
  {
      string_type* const storage = m_streambuf.storage();
      typename string_type::size_type const alignment_size =
          static_cast< typename string_type::size_type >(m_stream.width() - size);
      const bool align_left = (m_stream.flags() & ostream_type::adjustfield) == ostream_type::left;
      if (align_left)
      {
          aux::code_convert(p, static_cast< std::size_t >(size), *storage, m_stream.getloc());
          storage->append(alignment_size, m_stream.fill());
      }
      else
      {
          storage->append(alignment_size, m_stream.fill());
          aux::code_convert(p, static_cast< std::size_t >(size), *storage, m_stream.getloc());
      }
  }
  
  // Implementation note: these operators below should be the least attractive for the compiler
  // so that user's overloads are chosen, when present. We use function template partial ordering for this purpose.
  // We also don't use perfect forwarding for the right hand argument because in ths case the generic overload
  // would be more preferred than the typical one written by users:
  //
  // formatting_ostream& operator<< (formatting_ostream& strm, my_type const& arg);
  //
  // This is because my_type rvalues require adding const to the type, which counts as a conversion that is not required
  // if there is a perfect forwarding overload.
  template< typename StreamT, typename T >
  inline typename boost::log::aux::enable_if_formatting_ostream< StreamT, StreamT& >::type
  operator<< (StreamT& strm, T const& value)
  {
      strm.stream() << value;
      return strm;
  }
  
  template< typename StreamT, typename T >
  inline typename boost::log::aux::enable_if_formatting_ostream< StreamT, StreamT& >::type
  operator<< (StreamT& strm, T& value)
  {
      strm.stream() << value;
      return strm;
  }
  
  #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
  
  template< typename StreamT, typename T >
  inline typename boost::log::aux::enable_if_formatting_ostream< StreamT, StreamT& >::type
  operator<< (StreamT&& strm, T const& value)
  {
      strm.stream() << value;
      return strm;
  }
  
  template< typename StreamT, typename T >
  inline typename boost::log::aux::enable_if_formatting_ostream< StreamT, StreamT& >::type
  operator<< (StreamT&& strm, T& value)
  {
      strm.stream() << value;
      return strm;
  }
  
  #endif // !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
  
  BOOST_LOG_CLOSE_NAMESPACE // namespace log
  
  } // namespace boost
  
  #include <boost/log/detail/footer.hpp>
  
  #endif // BOOST_LOG_UTILITY_FORMATTING_OSTREAM_HPP_INCLUDED_
  