sstream
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// String based streams -*- C++ -*-
// Copyright (C) 1997-2024 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 <bits/requires_hosted.h> // iostream
#include <istream>
#include <ostream>
#include <bits/alloc_traits.h> // allocator_traits, __allocator_like
#if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
# define _GLIBCXX_LVAL_REF_QUAL &
# define _GLIBCXX_SSTREAM_ALWAYS_INLINE
#else
# define _GLIBCXX_LVAL_REF_QUAL
// For symbols that are not exported from libstdc++.so for the COW string ABI.
# define _GLIBCXX_SSTREAM_ALWAYS_INLINE [[__gnu__::__always_inline__]]
#endif
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;
#if __cplusplus >= 201103L
using allocator_traits = std::allocator_traits<_Alloc>;
using _Noexcept_swap
= __or_<typename allocator_traits::propagate_on_container_swap,
typename allocator_traits::is_always_equal>;
#endif
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); }
#if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
explicit
basic_stringbuf(const allocator_type& __a)
: basic_stringbuf(ios_base::in | std::ios_base::out, __a)
{ }
basic_stringbuf(ios_base::openmode __mode,
const allocator_type& __a)
: __streambuf_type(), _M_mode(__mode), _M_string(__a)
{ }
explicit
basic_stringbuf(__string_type&& __s,
ios_base::openmode __mode = ios_base::in
| ios_base::out)
: __streambuf_type(), _M_mode(__mode), _M_string(std::move(__s))
{ _M_stringbuf_init(__mode); }
template<typename _SAlloc>
basic_stringbuf(const basic_string<_CharT, _Traits, _SAlloc>& __s,
const allocator_type& __a)
: basic_stringbuf(__s, ios_base::in | std::ios_base::out, __a)
{ }
template<typename _SAlloc>
basic_stringbuf(const basic_string<_CharT, _Traits, _SAlloc>& __s,
ios_base::openmode __mode,
const allocator_type& __a)
: __streambuf_type(), _M_mode(__mode),
_M_string(__s.data(), __s.size(), __a)
{ _M_stringbuf_init(__mode); }
template<typename _SAlloc>
explicit
basic_stringbuf(const basic_string<_CharT, _Traits, _SAlloc>& __s,
ios_base::openmode __mode = ios_base::in
| ios_base::out)
: basic_stringbuf(__s, __mode, allocator_type{})
{ }
basic_stringbuf(basic_stringbuf&& __rhs, const allocator_type& __a)
: basic_stringbuf(std::move(__rhs), __a, __xfer_bufptrs(__rhs, this))
{ __rhs._M_sync(const_cast<char_type*>(__rhs._M_string.data()), 0, 0); }
allocator_type get_allocator() const noexcept
{ return _M_string.get_allocator(); }
#endif // C++20
// 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) noexcept(_Noexcept_swap::value)
{
__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); // XXX not exception safe
}
#endif // C++11
// Getters and setters:
/**
* @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 _GLIBCXX_LVAL_REF_QUAL
{
__string_type __ret(_M_string.get_allocator());
if (char_type* __hi = _M_high_mark())
__ret.assign(this->pbase(), __hi);
else
__ret = _M_string;
return __ret;
}
#if __cplusplus > 201703L
#if _GLIBCXX_USE_CXX11_ABI
#if __cpp_concepts
template<__allocator_like _SAlloc>
basic_string<_CharT, _Traits, _SAlloc>
str(const _SAlloc& __sa) const
{
auto __sv = view();
return { __sv.data(), __sv.size(), __sa };
}
#endif
__string_type
str() &&
{
if (char_type* __hi = _M_high_mark())
{
// Set length to end of character sequence and add null terminator.
_M_string._M_set_length(_M_high_mark() - this->pbase());
}
auto __str = std::move(_M_string);
_M_string.clear();
_M_sync(_M_string.data(), 0, 0);
return __str;
}
#endif // cxx11 ABI
_GLIBCXX_SSTREAM_ALWAYS_INLINE
basic_string_view<char_type, traits_type>
view() const noexcept
{
if (char_type* __hi = _M_high_mark())
return { this->pbase(), __hi };
else
return _M_string;
}
#endif // C++20
/**
* @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);
}
#if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
#if __cpp_concepts
template<__allocator_like _SAlloc>
requires (!is_same_v<_SAlloc, _Alloc>)
void
str(const basic_string<_CharT, _Traits, _SAlloc>& __s)
{
_M_string.assign(__s.data(), __s.size());
_M_stringbuf_init(_M_mode);
}
#endif
void
str(__string_type&& __s)
{
_M_string = std::move(__s);
_M_stringbuf_init(_M_mode);
}
#endif
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()
{
if (char_type* __pptr = this->pptr())
{
char_type* __egptr = this->egptr();
if (!__egptr || __pptr > __egptr)
{
if (_M_mode & ios_base::in)
this->setg(this->eback(), this->gptr(), __pptr);
else
this->setg(__pptr, __pptr, __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:
// Return a pointer to the end of the underlying character sequence.
// This might not be the same character as _M_string.end() because
// basic_stringbuf::overflow might have written to unused capacity
// in _M_string without updating its length.
__attribute__((__always_inline__))
char_type*
_M_high_mark() const _GLIBCXX_NOEXCEPT
{
if (char_type* __pptr = this->pptr())
{
char_type* __egptr = this->egptr();
if (!__egptr || __pptr > __egptr)
return __pptr; // Underlying sequence is [pbase, pptr).
else
return __egptr; // Underlying sequence is [pbase, egptr).
}
return 0; // Underlying character sequence is just _M_string.
}
#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 (!__end || __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))
{ }
#if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
// The move constructor initializes an __xfer_bufptrs temporary then
// delegates to this constructor to performs moves during its lifetime.
basic_stringbuf(basic_stringbuf&& __rhs, const allocator_type& __a,
__xfer_bufptrs&&)
: __streambuf_type(static_cast<const __streambuf_type&>(__rhs)),
_M_mode(__rhs._M_mode), _M_string(std::move(__rhs._M_string), __a)
{ }
#endif
#endif // C++11
};
// [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); }
#if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
basic_istringstream(ios_base::openmode __mode, const allocator_type& __a)
: __istream_type(), _M_stringbuf(__mode | ios_base::in, __a)
{ this->init(std::__addressof(_M_stringbuf)); }
explicit
basic_istringstream(__string_type&& __str,
ios_base::openmode __mode = ios_base::in)
: __istream_type(), _M_stringbuf(std::move(__str), __mode | ios_base::in)
{ this->init(std::__addressof(_M_stringbuf)); }
template<typename _SAlloc>
basic_istringstream(const basic_string<_CharT, _Traits, _SAlloc>& __str,
const allocator_type& __a)
: basic_istringstream(__str, ios_base::in, __a)
{ }
template<typename _SAlloc>
basic_istringstream(const basic_string<_CharT, _Traits, _SAlloc>& __str,
ios_base::openmode __mode,
const allocator_type& __a)
: __istream_type(), _M_stringbuf(__str, __mode | ios_base::in, __a)
{ this->init(std::__addressof(_M_stringbuf)); }
template<typename _SAlloc>
explicit
basic_istringstream(const basic_string<_CharT, _Traits, _SAlloc>& __str,
ios_base::openmode __mode = ios_base::in)
: basic_istringstream(__str, __mode, allocator_type())
{ }
#endif // C++20
// 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 // C++11
// 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 _GLIBCXX_LVAL_REF_QUAL
{ return _M_stringbuf.str(); }
#if __cplusplus > 201703L
#if _GLIBCXX_USE_CXX11_ABI
#if __cpp_concepts
template<__allocator_like _SAlloc>
basic_string<_CharT, _Traits, _SAlloc>
str(const _SAlloc& __sa) const
{ return _M_stringbuf.str(__sa); }
#endif
__string_type
str() &&
{ return std::move(_M_stringbuf).str(); }
#endif // cxx11 ABI
_GLIBCXX_SSTREAM_ALWAYS_INLINE
basic_string_view<char_type, traits_type>
view() const noexcept
{ return _M_stringbuf.view(); }
#endif // C++20
/**
* @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 > 201703L && _GLIBCXX_USE_CXX11_ABI
#if __cpp_concepts
template<__allocator_like _SAlloc>
requires (!is_same_v<_SAlloc, _Alloc>)
void
str(const basic_string<_CharT, _Traits, _SAlloc>& __s)
{ _M_stringbuf.str(__s); }
#endif
void
str(__string_type&& __s)
{ _M_stringbuf.str(std::move(__s)); }
#endif
};
// [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); }
#if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
basic_ostringstream(ios_base::openmode __mode, const allocator_type& __a)
: __ostream_type(), _M_stringbuf(__mode | ios_base::out, __a)
{ this->init(std::__addressof(_M_stringbuf)); }
explicit
basic_ostringstream(__string_type&& __str,
ios_base::openmode __mode = ios_base::out)
: __ostream_type(), _M_stringbuf(std::move(__str), __mode | ios_base::out)
{ this->init(std::__addressof(_M_stringbuf)); }
template<typename _SAlloc>
basic_ostringstream(const basic_string<_CharT, _Traits, _SAlloc>& __str,
const allocator_type& __a)
: basic_ostringstream(__str, ios_base::out, __a)
{ }
template<typename _SAlloc>
basic_ostringstream(const basic_string<_CharT, _Traits, _SAlloc>& __str,
ios_base::openmode __mode,
const allocator_type& __a)
: __ostream_type(), _M_stringbuf(__str, __mode | ios_base::out, __a)
{ this->init(std::__addressof(_M_stringbuf)); }
template<typename _SAlloc>
explicit
basic_ostringstream(const basic_string<_CharT, _Traits, _SAlloc>& __str,
ios_base::openmode __mode = ios_base::out)
: basic_ostringstream(__str, __mode, allocator_type())
{ }
#endif // C++20
// 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 // C++11
// 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 _GLIBCXX_LVAL_REF_QUAL
{ return _M_stringbuf.str(); }
#if __cplusplus > 201703L
#if _GLIBCXX_USE_CXX11_ABI
#if __cpp_concepts
template<__allocator_like _SAlloc>
basic_string<_CharT, _Traits, _SAlloc>
str(const _SAlloc& __sa) const
{ return _M_stringbuf.str(__sa); }
#endif
__string_type
str() &&
{ return std::move(_M_stringbuf).str(); }
#endif // cxx11 ABI
_GLIBCXX_SSTREAM_ALWAYS_INLINE
basic_string_view<char_type, traits_type>
view() const noexcept
{ return _M_stringbuf.view(); }
#endif // C++20
/**
* @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 > 201703L && _GLIBCXX_USE_CXX11_ABI
#if __cpp_concepts
template<__allocator_like _SAlloc>
requires (!is_same_v<_SAlloc, _Alloc>)
void
str(const basic_string<_CharT, _Traits, _SAlloc>& __s)
{ _M_stringbuf.str(__s); }
#endif
void
str(__string_type&& __s)
{ _M_stringbuf.str(std::move(__s)); }
#endif
};
// [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); }
#if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
basic_stringstream(ios_base::openmode __mode, const allocator_type& __a)
: __iostream_type(), _M_stringbuf(__mode, __a)
{ this->init(&_M_stringbuf); }
explicit
basic_stringstream(__string_type&& __str,
ios_base::openmode __mode = ios_base::in
| ios_base::out)
: __iostream_type(), _M_stringbuf(std::move(__str), __mode)
{ this->init(std::__addressof(_M_stringbuf)); }
template<typename _SAlloc>
basic_stringstream(const basic_string<_CharT, _Traits, _SAlloc>& __str,
const allocator_type& __a)
: basic_stringstream(__str, ios_base::in | ios_base::out, __a)
{ }
template<typename _SAlloc>
basic_stringstream(const basic_string<_CharT, _Traits, _SAlloc>& __str,
ios_base::openmode __mode,
const allocator_type& __a)
: __iostream_type(), _M_stringbuf(__str, __mode, __a)
{ this->init(std::__addressof(_M_stringbuf)); }
template<typename _SAlloc>
explicit
basic_stringstream(const basic_string<_CharT, _Traits, _SAlloc>& __str,
ios_base::openmode __mode = ios_base::in
| ios_base::out)
: basic_stringstream(__str, __mode, allocator_type())
{ }
#endif // C++20
// 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 // C++11
// 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 _GLIBCXX_LVAL_REF_QUAL
{ return _M_stringbuf.str(); }
#if __cplusplus > 201703L
#if _GLIBCXX_USE_CXX11_ABI
#if __cpp_concepts
template<__allocator_like _SAlloc>
basic_string<_CharT, _Traits, _SAlloc>
str(const _SAlloc& __sa) const
{ return _M_stringbuf.str(__sa); }
#endif
__string_type
str() &&
{ return std::move(_M_stringbuf).str(); }
#endif // cxx11 ABI
_GLIBCXX_SSTREAM_ALWAYS_INLINE
basic_string_view<char_type, traits_type>
view() const noexcept
{ return _M_stringbuf.view(); }
#endif // C++20
/**
* @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 > 201703L && _GLIBCXX_USE_CXX11_ABI
#if __cpp_concepts
template<__allocator_like _SAlloc>
requires (!is_same_v<_SAlloc, _Alloc>)
void
str(const basic_string<_CharT, _Traits, _SAlloc>& __s)
{ _M_stringbuf.str(__s); }
#endif
void
str(__string_type&& __s)
{ _M_stringbuf.str(std::move(__s)); }
#endif
};
#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)
noexcept(noexcept(__x.swap(__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 // C++11
_GLIBCXX_END_NAMESPACE_CXX11
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#undef _GLIBCXX_SSTREAM_ALWAYS_INLINE
#undef _GLIBCXX_LVAL_REF_QUAL
#include <bits/sstream.tcc>
#endif /* _GLIBCXX_SSTREAM */
istream
ostream
sstream.tcc
requires_hosted.h
std::move
constexpr std::remove_reference< _Tp >::type && move(_Tp &&__t) noexcept
Convert a value to an rvalue.
Definition move.h:137
std::__addressof
constexpr _Tp * __addressof(_Tp &__r) noexcept
Same as C++11 std::addressof.
Definition move.h:51
std
ISO C++ entities toplevel namespace is std.
std::streamsize
ptrdiff_t streamsize
Integral type for I/O operation counts and buffer sizes.
Definition postypes.h:68
std::size
constexpr auto size(const _Container &__cont) noexcept(noexcept(__cont.size())) -> decltype(__cont.size())
Return the size of a container.
Definition range_access.h:262
std::data
constexpr auto data(_Container &__cont) noexcept(noexcept(__cont.data())) -> decltype(__cont.data())
Return the data pointer of a container.
Definition range_access.h:312
__gnu_debug::__base
constexpr _Iterator __base(_Iterator __it)
Definition helper_functions.h:321
std::basic_ios::init
void init(basic_streambuf< _CharT, _Traits > *__sb)
All setup is performed here.
Definition basic_ios.tcc:126
std::basic_streambuf::pptr
char_type * pptr() const
Access to the put area.
Definition streambuf:539
std::basic_streambuf::char_type
_CharT char_type
Definition streambuf:133
std::basic_streambuf::setg
void setg(char_type *__gbeg, char_type *__gnext, char_type *__gend)
Setting the three read area pointers.
Definition streambuf:516
std::basic_streambuf::eback
char_type * eback() const
Access to the get area.
Definition streambuf:489
std::basic_streambuf::egptr
char_type * egptr() const
Access to the get area.
Definition streambuf:495
std::basic_streambuf::gptr
char_type * gptr() const
Access to the get area.
Definition streambuf:492
std::basic_streambuf::pubimbue
locale pubimbue(const locale &__loc)
Entry point for imbue().
Definition streambuf:216
std::basic_streambuf::pbase
char_type * pbase() const
Access to the put area.
Definition streambuf:536
std::basic_streambuf::off_type
traits_type::off_type off_type
Definition streambuf:137
std::basic_streambuf::basic_streambuf
basic_streambuf()
Base constructor.
Definition streambuf:470
std::basic_istream::basic_istream
basic_istream(__streambuf_type *__sb)
Base constructor.
Definition istream:95
std::basic_ostream::basic_ostream
basic_ostream(__streambuf_type *__sb)
Base constructor.
Definition ostream:92
std::basic_iostream::basic_iostream
basic_iostream(basic_streambuf< _CharT, _Traits > *__sb)
Constructor does nothing.
Definition istream:1008
std::basic_stringbuf
The actual work of input and output (for std::string).
Definition sstream:80
std::basic_stringbuf::showmanyc
virtual streamsize showmanyc()
Investigating the data available.
Definition sstream:345
std::basic_stringbuf::underflow
virtual int_type underflow()
Fetches more data from the controlled sequence.
Definition sstream.tcc:150
std::basic_stringbuf::seekpos
virtual pos_type seekpos(pos_type __sp, ios_base::openmode __mode=ios_base::in|ios_base::out)
Alters the stream positions.
Definition sstream.tcc:216
std::basic_stringbuf::seekoff
virtual pos_type seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __mode=ios_base::in|ios_base::out)
Alters the stream positions.
Definition sstream.tcc:168
std::basic_stringbuf::overflow
virtual int_type overflow(int_type __c=traits_type::eof())
Consumes data from the buffer; writes to the controlled sequence.
Definition sstream.tcc:80
std::basic_stringbuf::basic_stringbuf
basic_stringbuf()
Starts with an empty string buffer.
Definition sstream:120
std::basic_stringbuf::pbackfail
virtual int_type pbackfail(int_type __c=traits_type::eof())
Tries to back up the input sequence.
Definition sstream.tcc:46
std::basic_stringbuf::str
__string_type str() const &
Copying out the string buffer.
Definition sstream:248
std::basic_stringbuf::setbuf
virtual __streambuf_type * setbuf(char_type *__s, streamsize __n)
Manipulates the buffer.
Definition sstream:377
std::basic_stringbuf< char >::_M_mode
ios_base::openmode _M_mode
Definition sstream:106
std::basic_istringstream
Controlling input for std::string.
Definition sstream:548
std::basic_istringstream::str
void str(const __string_type &__s)
Setting a new buffer.
Definition sstream:736
std::basic_istringstream::rdbuf
__stringbuf_type * rdbuf() const
Accessing the underlying buffer.
Definition sstream:698
std::basic_istringstream::~basic_istringstream
~basic_istringstream()
The destructor does nothing.
Definition sstream:626
std::basic_istringstream::basic_istringstream
basic_istringstream(const __string_type &__str, ios_base::openmode __mode=ios_base::in)
Starts with an existing string buffer.
Definition sstream:615
std::basic_istringstream::str
__string_type str() const &
Copying out the string buffer.
Definition sstream:706
std::basic_istringstream::basic_istringstream
basic_istringstream()
Default constructor starts with an empty string buffer.
Definition sstream:580
std::basic_istringstream::basic_istringstream
basic_istringstream(ios_base::openmode __mode)
Starts with an empty string buffer.
Definition sstream:597
std::basic_ostringstream
Controlling output for std::string.
Definition sstream:772
std::basic_ostringstream::~basic_ostringstream
~basic_ostringstream()
The destructor does nothing.
Definition sstream:850
std::basic_ostringstream::str
void str(const __string_type &__s)
Setting a new buffer.
Definition sstream:960
std::basic_ostringstream::basic_ostringstream
basic_ostringstream()
Default constructor starts with an empty string buffer.
Definition sstream:804
std::basic_ostringstream::basic_ostringstream
basic_ostringstream(const __string_type &__str, ios_base::openmode __mode=ios_base::out)
Starts with an existing string buffer.
Definition sstream:839
std::basic_ostringstream::str
__string_type str() const &
Copying out the string buffer.
Definition sstream:930
std::basic_ostringstream::basic_ostringstream
basic_ostringstream(ios_base::openmode __mode)
Starts with an empty string buffer.
Definition sstream:821
std::basic_ostringstream::rdbuf
__stringbuf_type * rdbuf() const
Accessing the underlying buffer.
Definition sstream:922
std::basic_stringstream
Controlling input and output for std::string.
Definition sstream:996
std::basic_stringstream::~basic_stringstream
~basic_stringstream()
The destructor does nothing.
Definition sstream:1070
std::basic_stringstream::basic_stringstream
basic_stringstream(const __string_type &__str, ios_base::openmode __m=ios_base::out|ios_base::in)
Starts with an existing string buffer.
Definition sstream:1059
std::basic_stringstream::basic_stringstream
basic_stringstream()
Default constructor starts with an empty string buffer.
Definition sstream:1028
std::basic_stringstream::str
void str(const __string_type &__s)
Setting a new buffer.
Definition sstream:1182
std::basic_stringstream::str
__string_type str() const &
Copying out the string buffer.
Definition sstream:1152
std::basic_stringstream::rdbuf
__stringbuf_type * rdbuf() const
Accessing the underlying buffer.
Definition sstream:1144
std::basic_stringstream::basic_stringstream
basic_stringstream(ios_base::openmode __m)
Starts with an empty string buffer.
Definition sstream:1043
std::allocator_traits
Uniform interface to all allocator types.
Definition bits/alloc_traits.h:145
std::allocator_traits::is_always_equal
typename __detected_or_t< is_empty< _Alloc >, __equal, _Alloc >::type is_always_equal
Whether all instances of the allocator type compare equal.
Definition bits/alloc_traits.h:260
std::allocator_traits::propagate_on_container_swap
__detected_or_t< false_type, __pocs, _Alloc > propagate_on_container_swap
How the allocator is propagated on swap.
Definition bits/alloc_traits.h:252
std::basic_string
Managing sequences of characters and character-like objects.
Definition basic_string.h:87
std::basic_string::size
constexpr size_type size() const noexcept
Returns the number of characters in the string, not including any null-termination.
Definition basic_string.h:1076
std::basic_string::data
constexpr const _CharT * data() const noexcept
Return const pointer to contents.
Definition basic_string.h:2653
std::basic_string::assign
constexpr basic_string & assign(const basic_string &__str)
Set value to contents of another string.
Definition basic_string.h:1588
std::ios_base
The base of the I/O class hierarchy.
Definition ios_base.h:255
std::ios_base::in
static const openmode in
Open for input. Default for ifstream and fstream.
Definition ios_base.h:487
std::ios_base::out
static const openmode out
Open for output. Default for ofstream and fstream.
Definition ios_base.h:490
std::ios_base::openmode
_Ios_Openmode openmode
This is a bitmask type.
Definition ios_base.h:473
std::ios_base::app
static const openmode app
Seek to end before each write.
Definition ios_base.h:476
std::ios_base::seekdir
_Ios_Seekdir seekdir
This is an enumerated type.
Definition ios_base.h:512
std::ios_base::ate
static const openmode ate
Open and seek to end immediately after opening.
Definition ios_base.h:479
alloc_traits.h