// String based streams -*- C++ -*- // Copyright (C) 1997-2020 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 include/sstream * This is a Standard C++ Library header. */ // // ISO C++ 14882: 27.7 String-based streams // #ifndef _GLIBCXX_SSTREAM #define _GLIBCXX_SSTREAM 1 #pragma GCC system_header #include <istream> #include <ostream> namespace std _GLIBCXX_VISIBILITY(default) { _GLIBCXX_BEGIN_NAMESPACE_VERSION _GLIBCXX_BEGIN_NAMESPACE_CXX11 // [27.7.1] template class basic_stringbuf /** * @brief The actual work of input and output (for std::string). * @ingroup io * * @tparam _CharT Type of character stream. * @tparam _Traits Traits for character type, defaults to * char_traits<_CharT>. * @tparam _Alloc Allocator type, defaults to allocator<_CharT>. * * This class associates either or both of its input and output sequences * with a sequence of characters, which can be initialized from, or made * available as, a @c std::basic_string. (Paraphrased from [27.7.1]/1.) * * For this class, open modes (of type @c ios_base::openmode) have * @c in set if the input sequence can be read, and @c out set if the * output sequence can be written. */ template<typename _CharT, typename _Traits, typename _Alloc> class basic_stringbuf : public basic_streambuf<_CharT, _Traits> { struct __xfer_bufptrs; public: // Types: typedef _CharT char_type; typedef _Traits traits_type; // _GLIBCXX_RESOLVE_LIB_DEFECTS // 251. basic_stringbuf missing allocator_type typedef _Alloc allocator_type; typedef typename traits_type::int_type int_type; typedef typename traits_type::pos_type pos_type; typedef typename traits_type::off_type off_type; typedef basic_streambuf<char_type, traits_type> __streambuf_type; typedef basic_string<char_type, _Traits, _Alloc> __string_type; typedef typename __string_type::size_type __size_type; protected: /// Place to stash in || out || in | out settings for current stringbuf. ios_base::openmode _M_mode; // Data Members: __string_type _M_string; public: // Constructors: /** * @brief Starts with an empty string buffer. * * The default constructor initializes the parent class using its * own default ctor. */ basic_stringbuf() : __streambuf_type(), _M_mode(ios_base::in | ios_base::out), _M_string() { } /** * @brief Starts with an empty string buffer. * @param __mode Whether the buffer can read, or write, or both. * * The default constructor initializes the parent class using its * own default ctor. */ explicit basic_stringbuf(ios_base::openmode __mode) : __streambuf_type(), _M_mode(__mode), _M_string() { } /** * @brief Starts with an existing string buffer. * @param __str A string to copy as a starting buffer. * @param __mode Whether the buffer can read, or write, or both. * * This constructor initializes the parent class using its * own default ctor. */ explicit basic_stringbuf(const __string_type& __str, ios_base::openmode __mode = ios_base::in | ios_base::out) : __streambuf_type(), _M_mode(), _M_string(__str.data(), __str.size(), __str.get_allocator()) { _M_stringbuf_init(__mode); } #if __cplusplus >= 201103L basic_stringbuf(const basic_stringbuf&) = delete; basic_stringbuf(basic_stringbuf&& __rhs) : basic_stringbuf(std::move(__rhs), __xfer_bufptrs(__rhs, this)) { __rhs._M_sync(const_cast<char_type*>(__rhs._M_string.data()), 0, 0); } // 27.8.2.2 Assign and swap: basic_stringbuf& operator=(const basic_stringbuf&) = delete; basic_stringbuf& operator=(basic_stringbuf&& __rhs) { __xfer_bufptrs __st{__rhs, this}; const __streambuf_type& __base = __rhs; __streambuf_type::operator=(__base); this->pubimbue(__rhs.getloc()); _M_mode = __rhs._M_mode; _M_string = std::move(__rhs._M_string); __rhs._M_sync(const_cast<char_type*>(__rhs._M_string.data()), 0, 0); return *this; } void swap(basic_stringbuf& __rhs) { __xfer_bufptrs __l_st{*this, std::__addressof(__rhs)}; __xfer_bufptrs __r_st{__rhs, this}; __streambuf_type& __base = __rhs; __streambuf_type::swap(__base); __rhs.pubimbue(this->pubimbue(__rhs.getloc())); std::swap(_M_mode, __rhs._M_mode); std::swap(_M_string, __rhs._M_string); } #endif // Get and set: /** * @brief Copying out the string buffer. * @return A copy of one of the underlying sequences. * * <em>If the buffer is only created in input mode, the underlying * character sequence is equal to the input sequence; otherwise, it * is equal to the output sequence.</em> [27.7.1.2]/1 */ __string_type str() const { __string_type __ret(_M_string.get_allocator()); if (this->pptr()) { // The current egptr() may not be the actual string end. if (this->pptr() > this->egptr()) __ret.assign(this->pbase(), this->pptr()); else __ret.assign(this->pbase(), this->egptr()); } else __ret = _M_string; return __ret; } /** * @brief Setting a new buffer. * @param __s The string to use as a new sequence. * * Deallocates any previous stored sequence, then copies @a s to * use as a new one. */ void str(const __string_type& __s) { // Cannot use _M_string = __s, since v3 strings are COW // (not always true now but assign() always works). _M_string.assign(__s.data(), __s.size()); _M_stringbuf_init(_M_mode); } protected: // Common initialization code goes here. void _M_stringbuf_init(ios_base::openmode __mode) { _M_mode = __mode; __size_type __len = 0; if (_M_mode & (ios_base::ate | ios_base::app)) __len = _M_string.size(); _M_sync(const_cast<char_type*>(_M_string.data()), 0, __len); } virtual streamsize showmanyc() { streamsize __ret = -1; if (_M_mode & ios_base::in) { _M_update_egptr(); __ret = this->egptr() - this->gptr(); } return __ret; } virtual int_type underflow(); virtual int_type pbackfail(int_type __c = traits_type::eof()); virtual int_type overflow(int_type __c = traits_type::eof()); /** * @brief Manipulates the buffer. * @param __s Pointer to a buffer area. * @param __n Size of @a __s. * @return @c this * * If no buffer has already been created, and both @a __s and @a __n are * non-zero, then @c __s is used as a buffer; see * https://gcc.gnu.org/onlinedocs/libstdc++/manual/streambufs.html#io.streambuf.buffering * for more. */ virtual __streambuf_type* setbuf(char_type* __s, streamsize __n) { if (__s && __n >= 0) { // This is implementation-defined behavior, and assumes // that an external char_type array of length __n exists // and has been pre-allocated. If this is not the case, // things will quickly blow up. // Step 1: Destroy the current internal array. _M_string.clear(); // Step 2: Use the external array. _M_sync(__s, __n, 0); } return this; } virtual pos_type seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __mode = ios_base::in | ios_base::out); virtual pos_type seekpos(pos_type __sp, ios_base::openmode __mode = ios_base::in | ios_base::out); // Internal function for correctly updating the internal buffer // for a particular _M_string, due to initialization or re-sizing // of an existing _M_string. void _M_sync(char_type* __base, __size_type __i, __size_type __o); // Internal function for correctly updating egptr() to the actual // string end. void _M_update_egptr() { const bool __testin = _M_mode & ios_base::in; if (this->pptr() && this->pptr() > this->egptr()) { if (__testin) this->setg(this->eback(), this->gptr(), this->pptr()); else this->setg(this->pptr(), this->pptr(), this->pptr()); } } // Works around the issue with pbump, part of the protected // interface of basic_streambuf, taking just an int. void _M_pbump(char_type* __pbeg, char_type* __pend, off_type __off); private: #if __cplusplus >= 201103L #if _GLIBCXX_USE_CXX11_ABI // This type captures the state of the gptr / pptr pointers as offsets // so they can be restored in another object after moving the string. struct __xfer_bufptrs { __xfer_bufptrs(const basic_stringbuf& __from, basic_stringbuf* __to) : _M_to{__to}, _M_goff{-1, -1, -1}, _M_poff{-1, -1, -1} { const _CharT* const __str = __from._M_string.data(); const _CharT* __end = nullptr; if (__from.eback()) { _M_goff[0] = __from.eback() - __str; _M_goff[1] = __from.gptr() - __str; _M_goff[2] = __from.egptr() - __str; __end = __from.egptr(); } if (__from.pbase()) { _M_poff[0] = __from.pbase() - __str; _M_poff[1] = __from.pptr() - __from.pbase(); _M_poff[2] = __from.epptr() - __str; if (__from.pptr() > __end) __end = __from.pptr(); } // Set _M_string length to the greater of the get and put areas. if (__end) { // The const_cast avoids changing this constructor's signature, // because it is exported from the dynamic library. auto& __mut_from = const_cast<basic_stringbuf&>(__from); __mut_from._M_string._M_length(__end - __str); } } ~__xfer_bufptrs() { char_type* __str = const_cast<char_type*>(_M_to->_M_string.data()); if (_M_goff[0] != -1) _M_to->setg(__str+_M_goff[0], __str+_M_goff[1], __str+_M_goff[2]); if (_M_poff[0] != -1) _M_to->_M_pbump(__str+_M_poff[0], __str+_M_poff[2], _M_poff[1]); } basic_stringbuf* _M_to; off_type _M_goff[3]; off_type _M_poff[3]; }; #else // This type does nothing when using Copy-On-Write strings. struct __xfer_bufptrs { __xfer_bufptrs(const basic_stringbuf&, basic_stringbuf*) { } }; #endif // The move constructor initializes an __xfer_bufptrs temporary then // delegates to this constructor to performs moves during its lifetime. basic_stringbuf(basic_stringbuf&& __rhs, __xfer_bufptrs&&) : __streambuf_type(static_cast<const __streambuf_type&>(__rhs)), _M_mode(__rhs._M_mode), _M_string(std::move(__rhs._M_string)) { } #endif }; // [27.7.2] Template class basic_istringstream /** * @brief Controlling input for std::string. * @ingroup io * * @tparam _CharT Type of character stream. * @tparam _Traits Traits for character type, defaults to * char_traits<_CharT>. * @tparam _Alloc Allocator type, defaults to allocator<_CharT>. * * This class supports reading from objects of type std::basic_string, * using the inherited functions from std::basic_istream. To control * the associated sequence, an instance of std::basic_stringbuf is used, * which this page refers to as @c sb. */ template<typename _CharT, typename _Traits, typename _Alloc> class basic_istringstream : public basic_istream<_CharT, _Traits> { public: // Types: typedef _CharT char_type; typedef _Traits traits_type; // _GLIBCXX_RESOLVE_LIB_DEFECTS // 251. basic_stringbuf missing allocator_type typedef _Alloc allocator_type; typedef typename traits_type::int_type int_type; typedef typename traits_type::pos_type pos_type; typedef typename traits_type::off_type off_type; // Non-standard types: typedef basic_string<_CharT, _Traits, _Alloc> __string_type; typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type; typedef basic_istream<char_type, traits_type> __istream_type; private: __stringbuf_type _M_stringbuf; public: // Constructors: /** * @brief Default constructor starts with an empty string buffer. * * Initializes @c sb using @c in, and passes @c &sb to the base * class initializer. Does not allocate any buffer. * * That's a lie. We initialize the base class with NULL, because the * string class does its own memory management. */ basic_istringstream() : __istream_type(), _M_stringbuf(ios_base::in) { this->init(&_M_stringbuf); } /** * @brief Starts with an empty string buffer. * @param __mode Whether the buffer can read, or write, or both. * * @c ios_base::in is automatically included in @a __mode. * * Initializes @c sb using @c __mode|in, and passes @c &sb to the base * class initializer. Does not allocate any buffer. * * That's a lie. We initialize the base class with NULL, because the * string class does its own memory management. */ explicit basic_istringstream(ios_base::openmode __mode) : __istream_type(), _M_stringbuf(__mode | ios_base::in) { this->init(&_M_stringbuf); } /** * @brief Starts with an existing string buffer. * @param __str A string to copy as a starting buffer. * @param __mode Whether the buffer can read, or write, or both. * * @c ios_base::in is automatically included in @a mode. * * Initializes @c sb using @a str and @c mode|in, and passes @c &sb * to the base class initializer. * * That's a lie. We initialize the base class with NULL, because the * string class does its own memory management. */ explicit basic_istringstream(const __string_type& __str, ios_base::openmode __mode = ios_base::in) : __istream_type(), _M_stringbuf(__str, __mode | ios_base::in) { this->init(&_M_stringbuf); } /** * @brief The destructor does nothing. * * The buffer is deallocated by the stringbuf object, not the * formatting stream. */ ~basic_istringstream() { } #if __cplusplus >= 201103L basic_istringstream(const basic_istringstream&) = delete; basic_istringstream(basic_istringstream&& __rhs) : __istream_type(std::move(__rhs)), _M_stringbuf(std::move(__rhs._M_stringbuf)) { __istream_type::set_rdbuf(&_M_stringbuf); } // 27.8.3.2 Assign and swap: basic_istringstream& operator=(const basic_istringstream&) = delete; basic_istringstream& operator=(basic_istringstream&& __rhs) { __istream_type::operator=(std::move(__rhs)); _M_stringbuf = std::move(__rhs._M_stringbuf); return *this; } void swap(basic_istringstream& __rhs) { __istream_type::swap(__rhs); _M_stringbuf.swap(__rhs._M_stringbuf); } #endif // Members: /** * @brief Accessing the underlying buffer. * @return The current basic_stringbuf buffer. * * This hides both signatures of std::basic_ios::rdbuf(). */ __stringbuf_type* rdbuf() const { return const_cast<__stringbuf_type*>(&_M_stringbuf); } /** * @brief Copying out the string buffer. * @return @c rdbuf()->str() */ __string_type str() const { return _M_stringbuf.str(); } /** * @brief Setting a new buffer. * @param __s The string to use as a new sequence. * * Calls @c rdbuf()->str(s). */ void str(const __string_type& __s) { _M_stringbuf.str(__s); } }; // [27.7.3] Template class basic_ostringstream /** * @brief Controlling output for std::string. * @ingroup io * * @tparam _CharT Type of character stream. * @tparam _Traits Traits for character type, defaults to * char_traits<_CharT>. * @tparam _Alloc Allocator type, defaults to allocator<_CharT>. * * This class supports writing to objects of type std::basic_string, * using the inherited functions from std::basic_ostream. To control * the associated sequence, an instance of std::basic_stringbuf is used, * which this page refers to as @c sb. */ template <typename _CharT, typename _Traits, typename _Alloc> class basic_ostringstream : public basic_ostream<_CharT, _Traits> { public: // Types: typedef _CharT char_type; typedef _Traits traits_type; // _GLIBCXX_RESOLVE_LIB_DEFECTS // 251. basic_stringbuf missing allocator_type typedef _Alloc allocator_type; typedef typename traits_type::int_type int_type; typedef typename traits_type::pos_type pos_type; typedef typename traits_type::off_type off_type; // Non-standard types: typedef basic_string<_CharT, _Traits, _Alloc> __string_type; typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type; typedef basic_ostream<char_type, traits_type> __ostream_type; private: __stringbuf_type _M_stringbuf; public: // Constructors/destructor: /** * @brief Default constructor starts with an empty string buffer. * * Initializes @c sb using @c mode|out, and passes @c &sb to the base * class initializer. Does not allocate any buffer. * * That's a lie. We initialize the base class with NULL, because the * string class does its own memory management. */ basic_ostringstream() : __ostream_type(), _M_stringbuf(ios_base::out) { this->init(&_M_stringbuf); } /** * @brief Starts with an empty string buffer. * @param __mode Whether the buffer can read, or write, or both. * * @c ios_base::out is automatically included in @a mode. * * Initializes @c sb using @c mode|out, and passes @c &sb to the base * class initializer. Does not allocate any buffer. * * That's a lie. We initialize the base class with NULL, because the * string class does its own memory management. */ explicit basic_ostringstream(ios_base::openmode __mode) : __ostream_type(), _M_stringbuf(__mode | ios_base::out) { this->init(&_M_stringbuf); } /** * @brief Starts with an existing string buffer. * @param __str A string to copy as a starting buffer. * @param __mode Whether the buffer can read, or write, or both. * * @c ios_base::out is automatically included in @a mode. * * Initializes @c sb using @a str and @c mode|out, and passes @c &sb * to the base class initializer. * * That's a lie. We initialize the base class with NULL, because the * string class does its own memory management. */ explicit basic_ostringstream(const __string_type& __str, ios_base::openmode __mode = ios_base::out) : __ostream_type(), _M_stringbuf(__str, __mode | ios_base::out) { this->init(&_M_stringbuf); } /** * @brief The destructor does nothing. * * The buffer is deallocated by the stringbuf object, not the * formatting stream. */ ~basic_ostringstream() { } #if __cplusplus >= 201103L basic_ostringstream(const basic_ostringstream&) = delete; basic_ostringstream(basic_ostringstream&& __rhs) : __ostream_type(std::move(__rhs)), _M_stringbuf(std::move(__rhs._M_stringbuf)) { __ostream_type::set_rdbuf(&_M_stringbuf); } // 27.8.3.2 Assign and swap: basic_ostringstream& operator=(const basic_ostringstream&) = delete; basic_ostringstream& operator=(basic_ostringstream&& __rhs) { __ostream_type::operator=(std::move(__rhs)); _M_stringbuf = std::move(__rhs._M_stringbuf); return *this; } void swap(basic_ostringstream& __rhs) { __ostream_type::swap(__rhs); _M_stringbuf.swap(__rhs._M_stringbuf); } #endif // Members: /** * @brief Accessing the underlying buffer. * @return The current basic_stringbuf buffer. * * This hides both signatures of std::basic_ios::rdbuf(). */ __stringbuf_type* rdbuf() const { return const_cast<__stringbuf_type*>(&_M_stringbuf); } /** * @brief Copying out the string buffer. * @return @c rdbuf()->str() */ __string_type str() const { return _M_stringbuf.str(); } /** * @brief Setting a new buffer. * @param __s The string to use as a new sequence. * * Calls @c rdbuf()->str(s). */ void str(const __string_type& __s) { _M_stringbuf.str(__s); } }; // [27.7.4] Template class basic_stringstream /** * @brief Controlling input and output for std::string. * @ingroup io * * @tparam _CharT Type of character stream. * @tparam _Traits Traits for character type, defaults to * char_traits<_CharT>. * @tparam _Alloc Allocator type, defaults to allocator<_CharT>. * * This class supports reading from and writing to objects of type * std::basic_string, using the inherited functions from * std::basic_iostream. To control the associated sequence, an instance * of std::basic_stringbuf is used, which this page refers to as @c sb. */ template <typename _CharT, typename _Traits, typename _Alloc> class basic_stringstream : public basic_iostream<_CharT, _Traits> { public: // Types: typedef _CharT char_type; typedef _Traits traits_type; // _GLIBCXX_RESOLVE_LIB_DEFECTS // 251. basic_stringbuf missing allocator_type typedef _Alloc allocator_type; typedef typename traits_type::int_type int_type; typedef typename traits_type::pos_type pos_type; typedef typename traits_type::off_type off_type; // Non-standard Types: typedef basic_string<_CharT, _Traits, _Alloc> __string_type; typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type; typedef basic_iostream<char_type, traits_type> __iostream_type; private: __stringbuf_type _M_stringbuf; public: // Constructors/destructors /** * @brief Default constructor starts with an empty string buffer. * * Initializes @c sb using the mode @c in|out, and passes @c &sb * to the base class initializer. Does not allocate any buffer. * * That's a lie. We initialize the base class with NULL, because the * string class does its own memory management. */ basic_stringstream() : __iostream_type(), _M_stringbuf(ios_base::out | ios_base::in) { this->init(&_M_stringbuf); } /** * @brief Starts with an empty string buffer. * @param __m Whether the buffer can read, or write, or both. * * Initializes @c sb using the mode from @c __m, and passes @c &sb * to the base class initializer. Does not allocate any buffer. * * That's a lie. We initialize the base class with NULL, because the * string class does its own memory management. */ explicit basic_stringstream(ios_base::openmode __m) : __iostream_type(), _M_stringbuf(__m) { this->init(&_M_stringbuf); } /** * @brief Starts with an existing string buffer. * @param __str A string to copy as a starting buffer. * @param __m Whether the buffer can read, or write, or both. * * Initializes @c sb using @a __str and @c __m, and passes @c &sb * to the base class initializer. * * That's a lie. We initialize the base class with NULL, because the * string class does its own memory management. */ explicit basic_stringstream(const __string_type& __str, ios_base::openmode __m = ios_base::out | ios_base::in) : __iostream_type(), _M_stringbuf(__str, __m) { this->init(&_M_stringbuf); } /** * @brief The destructor does nothing. * * The buffer is deallocated by the stringbuf object, not the * formatting stream. */ ~basic_stringstream() { } #if __cplusplus >= 201103L basic_stringstream(const basic_stringstream&) = delete; basic_stringstream(basic_stringstream&& __rhs) : __iostream_type(std::move(__rhs)), _M_stringbuf(std::move(__rhs._M_stringbuf)) { __iostream_type::set_rdbuf(&_M_stringbuf); } // 27.8.3.2 Assign and swap: basic_stringstream& operator=(const basic_stringstream&) = delete; basic_stringstream& operator=(basic_stringstream&& __rhs) { __iostream_type::operator=(std::move(__rhs)); _M_stringbuf = std::move(__rhs._M_stringbuf); return *this; } void swap(basic_stringstream& __rhs) { __iostream_type::swap(__rhs); _M_stringbuf.swap(__rhs._M_stringbuf); } #endif // Members: /** * @brief Accessing the underlying buffer. * @return The current basic_stringbuf buffer. * * This hides both signatures of std::basic_ios::rdbuf(). */ __stringbuf_type* rdbuf() const { return const_cast<__stringbuf_type*>(&_M_stringbuf); } /** * @brief Copying out the string buffer. * @return @c rdbuf()->str() */ __string_type str() const { return _M_stringbuf.str(); } /** * @brief Setting a new buffer. * @param __s The string to use as a new sequence. * * Calls @c rdbuf()->str(s). */ void str(const __string_type& __s) { _M_stringbuf.str(__s); } }; #if __cplusplus >= 201103L /// Swap specialization for stringbufs. template <class _CharT, class _Traits, class _Allocator> inline void swap(basic_stringbuf<_CharT, _Traits, _Allocator>& __x, basic_stringbuf<_CharT, _Traits, _Allocator>& __y) { __x.swap(__y); } /// Swap specialization for istringstreams. template <class _CharT, class _Traits, class _Allocator> inline void swap(basic_istringstream<_CharT, _Traits, _Allocator>& __x, basic_istringstream<_CharT, _Traits, _Allocator>& __y) { __x.swap(__y); } /// Swap specialization for ostringstreams. template <class _CharT, class _Traits, class _Allocator> inline void swap(basic_ostringstream<_CharT, _Traits, _Allocator>& __x, basic_ostringstream<_CharT, _Traits, _Allocator>& __y) { __x.swap(__y); } /// Swap specialization for stringstreams. template <class _CharT, class _Traits, class _Allocator> inline void swap(basic_stringstream<_CharT, _Traits, _Allocator>& __x, basic_stringstream<_CharT, _Traits, _Allocator>& __y) { __x.swap(__y); } #endif _GLIBCXX_END_NAMESPACE_CXX11 _GLIBCXX_END_NAMESPACE_VERSION } // namespace #include <bits/sstream.tcc> #endif /* _GLIBCXX_SSTREAM */