termcolor.hpp

//!
//! termcolor
//! ~~~~~~~~~
//!
//! termcolor is a header-only c++ library for printing colored messages
//! to the terminal. Written just for fun with a help of the Force.
//!
//! :copyright: (c) 2013 by Ihor Kalnytskyi
//! :license: BSD, see LICENSE for details
//!

#ifndef TERMCOLOR_HPP_
#define TERMCOLOR_HPP_

#include <iostream>

// Detect target's platform and set some macros in order to wrap platform
// specific code this library depends on.
#if defined(_WIN32) || defined(_WIN64)
#   define TERMCOLOR_TARGET_WINDOWS
#elif defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))
#   define TERMCOLOR_TARGET_POSIX
#endif

// If implementation has not been explicitly set, try to choose one based on
// target platform.
#if !defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES) && !defined(TERMCOLOR_USE_WINDOWS_API) && !defined(TERMCOLOR_USE_NOOP)
#   if defined(TERMCOLOR_TARGET_POSIX)
#       define TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES
#       define TERMCOLOR_AUTODETECTED_IMPLEMENTATION
#   elif defined(TERMCOLOR_TARGET_WINDOWS)
#       define TERMCOLOR_USE_WINDOWS_API
#       define TERMCOLOR_AUTODETECTED_IMPLEMENTATION
#   endif
#endif

// These headers provide isatty()/fileno() functions, which are used for
// testing whether a standard stream refers to the terminal.
#if defined(TERMCOLOR_TARGET_POSIX)
#   include <unistd.h>
#elif defined(TERMCOLOR_TARGET_WINDOWS)
#   include <io.h>
#   include <windows.h>
#endif

namespace termcolor {
  // Forward declaration of the `_internal` namespace.
  // All comments are below.
  namespace _internal {
    inline int colorize_index();

    inline FILE *get_standard_stream(const std::ostream &stream);

    inline FILE *get_standard_stream(const std::wostream &stream);

    template<typename CharT>
    bool is_colorized(std::basic_ostream<CharT> &stream);

    template<typename CharT>
    bool is_atty(const std::basic_ostream<CharT> &stream);

#if defined(TERMCOLOR_TARGET_WINDOWS)
        template <typename CharT>
        void win_change_attributes(std::basic_ostream<CharT>& stream, int foreground, int background = -1);
#endif
  }

  template<typename CharT>
  std::basic_ostream<CharT> &colorize(std::basic_ostream<CharT> &stream) {
    stream.iword(_internal::colorize_index()) = 1L;
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &nocolorize(std::basic_ostream<CharT> &stream) {
    stream.iword(_internal::colorize_index()) = 0L;
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &reset(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[00m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream, -1, -1);
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &bold(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[1m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &dark(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[2m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &italic(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[3m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &underline(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[4m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream, -1, COMMON_LVB_UNDERSCORE);
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &blink(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[5m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &reverse(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[7m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &concealed(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[8m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &crossed(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[9m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
#endif
    }
    return stream;
  }

  template<uint8_t code, typename CharT>
  std::basic_ostream<CharT> &color(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[38;5;" << +code << "m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
#endif
    }
    return stream;
  }

  template<uint8_t code, typename CharT>
  std::basic_ostream<CharT> &on_color(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[48;5;" << +code << "m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
#endif
    }
    return stream;
  }

  template<uint8_t r, uint8_t g, uint8_t b, typename CharT>
  std::basic_ostream<CharT> &color(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[38;2;" << +r << ";" << +g << ";" << +b << "m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
#endif
    }
    return stream;
  }

  template<uint8_t r, uint8_t g, uint8_t b, typename CharT>
  std::basic_ostream<CharT> &on_color(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[48;2;" << +r << ";" << +g << ";" << +b << "m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &grey(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[30m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream,
                0   // grey (black)
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &red(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[31m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream,
                FOREGROUND_RED
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &green(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[32m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream,
                FOREGROUND_GREEN
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &yellow(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[33m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream,
                FOREGROUND_GREEN | FOREGROUND_RED
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &blue(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[34m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream,
                FOREGROUND_BLUE
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &magenta(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[35m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream,
                FOREGROUND_BLUE | FOREGROUND_RED
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &cyan(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[36m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream,
                FOREGROUND_BLUE | FOREGROUND_GREEN
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &white(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[37m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream,
                FOREGROUND_BLUE | FOREGROUND_GREEN | FOREGROUND_RED
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &bright_grey(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[90m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream,
                0 | FOREGROUND_INTENSITY   // grey (black)
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &bright_red(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[91m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream,
                FOREGROUND_RED | FOREGROUND_INTENSITY
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &bright_green(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[92m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream,
                FOREGROUND_GREEN | FOREGROUND_INTENSITY
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &bright_yellow(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[93m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream,
                FOREGROUND_GREEN | FOREGROUND_RED | FOREGROUND_INTENSITY
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &bright_blue(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[94m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream,
                FOREGROUND_BLUE | FOREGROUND_INTENSITY
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &bright_magenta(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[95m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream,
                FOREGROUND_BLUE | FOREGROUND_RED | FOREGROUND_INTENSITY
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &bright_cyan(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[96m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream,
                FOREGROUND_BLUE | FOREGROUND_GREEN | FOREGROUND_INTENSITY
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &bright_white(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[97m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream,
                FOREGROUND_BLUE | FOREGROUND_GREEN | FOREGROUND_RED | FOREGROUND_INTENSITY
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &on_grey(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[40m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream, -1,
                0   // grey (black)
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &on_red(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[41m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream, -1,
                BACKGROUND_RED
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &on_green(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[42m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream, -1,
                BACKGROUND_GREEN
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &on_yellow(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[43m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream, -1,
                BACKGROUND_GREEN | BACKGROUND_RED
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &on_blue(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[44m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream, -1,
                BACKGROUND_BLUE
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &on_magenta(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[45m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream, -1,
                BACKGROUND_BLUE | BACKGROUND_RED
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &on_cyan(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[46m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream, -1,
                BACKGROUND_GREEN | BACKGROUND_BLUE
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &on_white(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[47m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream, -1,
                BACKGROUND_GREEN | BACKGROUND_BLUE | BACKGROUND_RED
            );
#endif
    }

    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &on_bright_grey(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[100m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream, -1,
                0 | BACKGROUND_INTENSITY   // grey (black)
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &on_bright_red(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[101m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream, -1,
                BACKGROUND_RED | BACKGROUND_INTENSITY
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &on_bright_green(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[102m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream, -1,
                BACKGROUND_GREEN | BACKGROUND_INTENSITY
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &on_bright_yellow(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[103m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream, -1,
                BACKGROUND_GREEN | BACKGROUND_RED | BACKGROUND_INTENSITY
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &on_bright_blue(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[104m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream, -1,
                BACKGROUND_BLUE | BACKGROUND_INTENSITY
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &on_bright_magenta(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[105m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream, -1,
                BACKGROUND_BLUE | BACKGROUND_RED | BACKGROUND_INTENSITY
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &on_bright_cyan(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[106m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream, -1,
                BACKGROUND_GREEN | BACKGROUND_BLUE | BACKGROUND_INTENSITY
            );
#endif
    }
    return stream;
  }

  template<typename CharT>
  std::basic_ostream<CharT> &on_bright_white(std::basic_ostream<CharT> &stream) {
    if (_internal::is_colorized(stream)) {
#if defined(TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES)
      stream << "\033[107m";
#elif defined(TERMCOLOR_USE_WINDOWS_API)
            _internal::win_change_attributes(stream, -1,
                BACKGROUND_GREEN | BACKGROUND_BLUE | BACKGROUND_RED | BACKGROUND_INTENSITY
            );
#endif
    }

    return stream;
  }

  //! Since C++ hasn't a way to hide something in the header from
  //! the outer access, I have to introduce this namespace which
  //! is used for internal purpose and should't be access from
  //! the user code.
  namespace _internal {
    // An index to be used to access a private storage of I/O streams. See
    // colorize / nocolorize I/O manipulators for details. Due to the fact
    // that static variables ain't shared between translation units, inline
    // function with local static variable is used to do the trick and share
    // the variable value between translation units.
    inline int colorize_index() {
      static int colorize_index = std::ios_base::xalloc();
      return colorize_index;
    }

    //! Since C++ hasn't a true way to extract stream handler
    //! from the a given `std::ostream` object, I have to write
    //! this kind of hack.
    inline FILE *get_standard_stream(const std::ostream &stream) {
      if (&stream == &std::cout)
        return stdout;
      else if (&stream == &std::cerr || &stream == &std::clog)
        return stderr;

      return nullptr;
    }

    //! Since C++ hasn't a true way to extract stream handler
    //! from the a given `std::wostream` object, I have to write
    //! this kind of hack.
    inline FILE *get_standard_stream(const std::wostream &stream) {
      if (&stream == &std::wcout)
        return stdout;
      else if (&stream == &std::wcerr || &stream == &std::wclog)
        return stderr;

      return nullptr;
    }

    // Say whether a given stream should be colorized or not. It's always
    // true for ATTY streams and may be true for streams marked with
    // colorize flag.
    template<typename CharT>
    bool is_colorized(std::basic_ostream<CharT> &stream) { return is_atty(stream) || static_cast<bool>(stream.iword(colorize_index())); }

    //! Test whether a given `std::ostream` object refers to
    //! a terminal.
    template<typename CharT>
    bool is_atty(const std::basic_ostream<CharT> &stream) {
      FILE *std_stream = get_standard_stream(stream);

      // Unfortunately, fileno() ends with segmentation fault
      // if invalid file descriptor is passed. So we need to
      // handle this case gracefully and assume it's not a tty
      // if standard stream is not detected, and 0 is returned.
      if (!std_stream)
        return false;

#if defined(TERMCOLOR_TARGET_POSIX)
      return ::isatty(fileno(std_stream));
#elif defined(TERMCOLOR_TARGET_WINDOWS)
            return ::_isatty(_fileno(std_stream));
#else
            return false;
#endif
    }

#if defined(TERMCOLOR_TARGET_WINDOWS)

        //! same hack as used in get_standard_stream function, but for Windows with `std::ostream`
        inline HANDLE get_terminal_handle(std::ostream& stream)
        {
            if (&stream == &std::cout)
                return GetStdHandle(STD_OUTPUT_HANDLE);
            else if (&stream == &std::cerr || &stream == &std::clog)
                return GetStdHandle(STD_ERROR_HANDLE);
            return nullptr;
        }

        //! same hack as used in get_standard_stream function, but for Windows with `std::wostream`
        inline HANDLE get_terminal_handle(std::wostream& stream)
        {
            if (&stream == &std::wcout)
                return GetStdHandle(STD_OUTPUT_HANDLE);
            else if (&stream == &std::wcerr || &stream == &std::wclog)
                return GetStdHandle(STD_ERROR_HANDLE);
            return nullptr;
        }

        //! Change Windows Terminal colors attribute. If some
        //! parameter is `-1` then attribute won't changed.
        template <typename CharT>
        void win_change_attributes(std::basic_ostream<CharT>& stream, int foreground, int background)
        {
            // yeah, i know.. it's ugly, it's windows.
            static WORD defaultAttributes = 0;

            // Windows doesn't have ANSI escape sequences and so we use special
            // API to change Terminal output color. That means we can't
            // manipulate colors by means of "std::stringstream" and hence
            // should do nothing in this case.
            if (!_internal::is_atty(stream))
                return;

            // get terminal handle
            HANDLE hTerminal = INVALID_HANDLE_VALUE;
            hTerminal = get_terminal_handle(stream);

            // save default terminal attributes if it unsaved
            if (!defaultAttributes)
            {
                CONSOLE_SCREEN_BUFFER_INFO info;
                if (!GetConsoleScreenBufferInfo(hTerminal, &info))
                    return;
                defaultAttributes = info.wAttributes;
            }

            // restore all default settings
            if (foreground == -1 && background == -1)
            {
                SetConsoleTextAttribute(hTerminal, defaultAttributes);
                return;
            }

            // get current settings
            CONSOLE_SCREEN_BUFFER_INFO info;
            if (!GetConsoleScreenBufferInfo(hTerminal, &info))
                return;

            if (foreground != -1)
            {
                info.wAttributes &= ~(info.wAttributes & 0x0F);
                info.wAttributes |= static_cast<WORD>(foreground);
            }

            if (background != -1)
            {
                info.wAttributes &= ~(info.wAttributes & 0xF0);
                info.wAttributes |= static_cast<WORD>(background);
            }

            SetConsoleTextAttribute(hTerminal, info.wAttributes);
        }
#endif // TERMCOLOR_TARGET_WINDOWS
  } // namespace _internal
} // namespace termcolor

#undef TERMCOLOR_TARGET_POSIX
#undef TERMCOLOR_TARGET_WINDOWS

#if defined(TERMCOLOR_AUTODETECTED_IMPLEMENTATION)
#   undef TERMCOLOR_USE_ANSI_ESCAPE_SEQUENCES
#   undef TERMCOLOR_USE_WINDOWS_API
#endif

#endif // TERMCOLOR_HPP_