quoted_string.h

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// Helpers for quoted stream manipulators -*- C++ -*-

// Copyright (C) 2013-2019 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// <http://www.gnu.org/licenses/>.

/** @file bits/quoted_string.h
 *  This is an internal header file, included by other library headers.
 *  Do not attempt to use it directly. @headername{iomanip}
 */

#ifndef _GLIBCXX_QUOTED_STRING_H
#define _GLIBCXX_QUOTED_STRING_H 1

#pragma GCC system_header

#if __cplusplus < 201103L
# include <bits/c++0x_warning.h>
#else
#include <sstream>

namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

  namespace __detail {
    /**
     * @brief Struct for delimited strings.
     */
    template<typename _String, typename _CharT>
      struct _Quoted_string
      {
        static_assert(is_reference<_String>::value
                   || is_pointer<_String>::value,
                      "String type must be pointer or reference");

        _Quoted_string(_String __str, _CharT __del, _CharT __esc)
        : _M_string(__str), _M_delim{__del}, _M_escape{__esc}
        { }

        _Quoted_string&
        operator=(_Quoted_string&) = delete;

        _String _M_string;
        _CharT _M_delim;
        _CharT _M_escape;
      };

#if __cplusplus >= 201703L
    template<typename _CharT, typename _Traits>
      struct _Quoted_string<basic_string_view<_CharT, _Traits>, _CharT>
      {
        _Quoted_string(basic_string_view<_CharT, _Traits> __str,
                       _CharT __del, _CharT __esc)
        : _M_string(__str), _M_delim{__del}, _M_escape{__esc}
        { }

        _Quoted_string&
        operator=(_Quoted_string&) = delete;

        basic_string_view<_CharT, _Traits> _M_string;
        _CharT _M_delim;
        _CharT _M_escape;
      };
#endif // C++17

    /**
     * @brief Inserter for quoted strings.
     *
     *  _GLIBCXX_RESOLVE_LIB_DEFECTS
     *  DR 2344 quoted()'s interaction with padding is unclear
     */
    template<typename _CharT, typename _Traits>
      std::basic_ostream<_CharT, _Traits>&
      operator<<(std::basic_ostream<_CharT, _Traits>& __os,
                 const _Quoted_string<const _CharT*, _CharT>& __str)
      {
        std::basic_ostringstream<_CharT, _Traits> __ostr;
        __ostr << __str._M_delim;
        for (const _CharT* __c = __str._M_string; *__c; ++__c)
          {
            if (*__c == __str._M_delim || *__c == __str._M_escape)
              __ostr << __str._M_escape;
            __ostr << *__c;
          }
        __ostr << __str._M_delim;

        return __os << __ostr.str();
      }

    /**
     * @brief Inserter for quoted strings.
     *
     *  _GLIBCXX_RESOLVE_LIB_DEFECTS
     *  DR 2344 quoted()'s interaction with padding is unclear
     */
    template<typename _CharT, typename _Traits, typename _String>
      std::basic_ostream<_CharT, _Traits>&
      operator<<(std::basic_ostream<_CharT, _Traits>& __os,
                 const _Quoted_string<_String, _CharT>& __str)
      {
        std::basic_ostringstream<_CharT, _Traits> __ostr;
        __ostr << __str._M_delim;
        for (auto __c : __str._M_string)
          {
            if (__c == __str._M_delim || __c == __str._M_escape)
              __ostr << __str._M_escape;
            __ostr << __c;
          }
        __ostr << __str._M_delim;

        return __os << __ostr.str();
      }

    /**
     * @brief Extractor for delimited strings.
     *        The left and right delimiters can be different.
     */
    template<typename _CharT, typename _Traits, typename _Alloc>
      std::basic_istream<_CharT, _Traits>&
      operator>>(std::basic_istream<_CharT, _Traits>& __is,
                 const _Quoted_string<basic_string<_CharT, _Traits, _Alloc>&,
                                      _CharT>& __str)
      {
        _CharT __c;
        __is >> __c;
        if (!__is.good())
          return __is;
        if (__c != __str._M_delim)
          {
            __is.unget();
            __is >> __str._M_string;
            return __is;
          }
        __str._M_string.clear();
        std::ios_base::fmtflags __flags
          = __is.flags(__is.flags() & ~std::ios_base::skipws);
        do
          {
            __is >> __c;
            if (!__is.good())
              break;
            if (__c == __str._M_escape)
              {
                __is >> __c;
                if (!__is.good())
                  break;
              }
            else if (__c == __str._M_delim)
              break;
            __str._M_string += __c;
          }
        while (true);
        __is.setf(__flags);

        return __is;
      }
  } // namespace __detail

_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std

#endif // C++11
#endif /* _GLIBCXX_QUOTED_STRING_H */