streambuf_iterator.h
Go to the documentation of this file.
// Streambuf iterators
// Copyright (C) 1997-2019 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/streambuf_iterator.h
* This is an internal header file, included by other library headers.
* Do not attempt to use it directly. @headername{iterator}
*/
#ifndef _STREAMBUF_ITERATOR_H
#define _STREAMBUF_ITERATOR_H 1
#pragma GCC system_header
#include <streambuf>
#include <debug/debug.h>
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
/**
* @addtogroup iterators
* @{
*/
// 24.5.3 Template class istreambuf_iterator
/// Provides input iterator semantics for streambufs.
template<typename _CharT, typename _Traits>
class istreambuf_iterator
: public iterator<input_iterator_tag, _CharT, typename _Traits::off_type,
_CharT*,
#if __cplusplus >= 201103L
// LWG 445.
_CharT>
#else
_CharT&>
#endif
{
public:
// Types:
///@{
/// Public typedefs
typedef _CharT char_type;
typedef _Traits traits_type;
typedef typename _Traits::int_type int_type;
typedef basic_streambuf<_CharT, _Traits> streambuf_type;
typedef basic_istream<_CharT, _Traits> istream_type;
///@}
template<typename _CharT2>
friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value,
ostreambuf_iterator<_CharT2> >::__type
copy(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>,
ostreambuf_iterator<_CharT2>);
template<bool _IsMove, typename _CharT2>
friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value,
_CharT2*>::__type
__copy_move_a2(istreambuf_iterator<_CharT2>,
istreambuf_iterator<_CharT2>, _CharT2*);
template<typename _CharT2>
friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value,
istreambuf_iterator<_CharT2> >::__type
find(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>,
const _CharT2&);
template<typename _CharT2, typename _Distance>
friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value,
void>::__type
advance(istreambuf_iterator<_CharT2>&, _Distance);
private:
// 24.5.3 istreambuf_iterator
// p 1
// If the end of stream is reached (streambuf_type::sgetc()
// returns traits_type::eof()), the iterator becomes equal to
// the "end of stream" iterator value.
// NB: This implementation assumes the "end of stream" value
// is EOF, or -1.
mutable streambuf_type* _M_sbuf;
int_type _M_c;
public:
/// Construct end of input stream iterator.
_GLIBCXX_CONSTEXPR istreambuf_iterator() _GLIBCXX_USE_NOEXCEPT
: _M_sbuf(0), _M_c(traits_type::eof()) { }
#if __cplusplus >= 201103L
istreambuf_iterator(const istreambuf_iterator&) noexcept = default;
~istreambuf_iterator() = default;
#endif
/// Construct start of input stream iterator.
istreambuf_iterator(istream_type& __s) _GLIBCXX_USE_NOEXCEPT
: _M_sbuf(__s.rdbuf()), _M_c(traits_type::eof()) { }
/// Construct start of streambuf iterator.
istreambuf_iterator(streambuf_type* __s) _GLIBCXX_USE_NOEXCEPT
: _M_sbuf(__s), _M_c(traits_type::eof()) { }
#if __cplusplus >= 201103L
istreambuf_iterator&
operator=(const istreambuf_iterator&) noexcept = default;
#endif
/// Return the current character pointed to by iterator. This returns
/// streambuf.sgetc(). It cannot be assigned. NB: The result of
/// operator*() on an end of stream is undefined.
char_type
operator*() const
{
int_type __c = _M_get();
#ifdef _GLIBCXX_DEBUG_PEDANTIC
// Dereferencing a past-the-end istreambuf_iterator is a
// libstdc++ extension
__glibcxx_requires_cond(!_S_is_eof(__c),
_M_message(__gnu_debug::__msg_deref_istreambuf)
._M_iterator(*this));
#endif
return traits_type::to_char_type(__c);
}
/// Advance the iterator. Calls streambuf.sbumpc().
istreambuf_iterator&
operator++()
{
__glibcxx_requires_cond(_M_sbuf &&
(!_S_is_eof(_M_c) || !_S_is_eof(_M_sbuf->sgetc())),
_M_message(__gnu_debug::__msg_inc_istreambuf)
._M_iterator(*this));
_M_sbuf->sbumpc();
_M_c = traits_type::eof();
return *this;
}
/// Advance the iterator. Calls streambuf.sbumpc().
istreambuf_iterator
operator++(int)
{
__glibcxx_requires_cond(_M_sbuf &&
(!_S_is_eof(_M_c) || !_S_is_eof(_M_sbuf->sgetc())),
_M_message(__gnu_debug::__msg_inc_istreambuf)
._M_iterator(*this));
istreambuf_iterator __old = *this;
__old._M_c = _M_sbuf->sbumpc();
_M_c = traits_type::eof();
return __old;
}
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 110 istreambuf_iterator::equal not const
// NB: there is also number 111 (NAD) relevant to this function.
/// Return true both iterators are end or both are not end.
bool
equal(const istreambuf_iterator& __b) const
{ return _M_at_eof() == __b._M_at_eof(); }
private:
int_type
_M_get() const
{
int_type __ret = _M_c;
if (_M_sbuf && _S_is_eof(__ret) && _S_is_eof(__ret = _M_sbuf->sgetc()))
_M_sbuf = 0;
return __ret;
}
bool
_M_at_eof() const
{ return _S_is_eof(_M_get()); }
static bool
_S_is_eof(int_type __c)
{
const int_type __eof = traits_type::eof();
return traits_type::eq_int_type(__c, __eof);
}
};
template<typename _CharT, typename _Traits>
inline bool
operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
const istreambuf_iterator<_CharT, _Traits>& __b)
{ return __a.equal(__b); }
template<typename _CharT, typename _Traits>
inline bool
operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
const istreambuf_iterator<_CharT, _Traits>& __b)
{ return !__a.equal(__b); }
/// Provides output iterator semantics for streambufs.
template<typename _CharT, typename _Traits>
class ostreambuf_iterator
: public iterator<output_iterator_tag, void, void, void, void>
{
public:
// Types:
///@{
/// Public typedefs
typedef _CharT char_type;
typedef _Traits traits_type;
typedef basic_streambuf<_CharT, _Traits> streambuf_type;
typedef basic_ostream<_CharT, _Traits> ostream_type;
///@}
template<typename _CharT2>
friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value,
ostreambuf_iterator<_CharT2> >::__type
copy(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>,
ostreambuf_iterator<_CharT2>);
private:
streambuf_type* _M_sbuf;
bool _M_failed;
public:
/// Construct output iterator from ostream.
ostreambuf_iterator(ostream_type& __s) _GLIBCXX_USE_NOEXCEPT
: _M_sbuf(__s.rdbuf()), _M_failed(!_M_sbuf) { }
/// Construct output iterator from streambuf.
ostreambuf_iterator(streambuf_type* __s) _GLIBCXX_USE_NOEXCEPT
: _M_sbuf(__s), _M_failed(!_M_sbuf) { }
/// Write character to streambuf. Calls streambuf.sputc().
ostreambuf_iterator&
operator=(_CharT __c)
{
if (!_M_failed &&
_Traits::eq_int_type(_M_sbuf->sputc(__c), _Traits::eof()))
_M_failed = true;
return *this;
}
/// Return *this.
ostreambuf_iterator&
operator*()
{ return *this; }
/// Return *this.
ostreambuf_iterator&
operator++(int)
{ return *this; }
/// Return *this.
ostreambuf_iterator&
operator++()
{ return *this; }
/// Return true if previous operator=() failed.
bool
failed() const _GLIBCXX_USE_NOEXCEPT
{ return _M_failed; }
ostreambuf_iterator&
_M_put(const _CharT* __ws, streamsize __len)
{
if (__builtin_expect(!_M_failed, true)
&& __builtin_expect(this->_M_sbuf->sputn(__ws, __len) != __len,
false))
_M_failed = true;
return *this;
}
};
// Overloads for streambuf iterators.
template<typename _CharT>
typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
ostreambuf_iterator<_CharT> >::__type
copy(istreambuf_iterator<_CharT> __first,
istreambuf_iterator<_CharT> __last,
ostreambuf_iterator<_CharT> __result)
{
if (__first._M_sbuf && !__last._M_sbuf && !__result._M_failed)
{
bool __ineof;
__copy_streambufs_eof(__first._M_sbuf, __result._M_sbuf, __ineof);
if (!__ineof)
__result._M_failed = true;
}
return __result;
}
template<bool _IsMove, typename _CharT>
typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
ostreambuf_iterator<_CharT> >::__type
__copy_move_a2(_CharT* __first, _CharT* __last,
ostreambuf_iterator<_CharT> __result)
{
const streamsize __num = __last - __first;
if (__num > 0)
__result._M_put(__first, __num);
return __result;
}
template<bool _IsMove, typename _CharT>
typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
ostreambuf_iterator<_CharT> >::__type
__copy_move_a2(const _CharT* __first, const _CharT* __last,
ostreambuf_iterator<_CharT> __result)
{
const streamsize __num = __last - __first;
if (__num > 0)
__result._M_put(__first, __num);
return __result;
}
template<bool _IsMove, typename _CharT>
typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
_CharT*>::__type
__copy_move_a2(istreambuf_iterator<_CharT> __first,
istreambuf_iterator<_CharT> __last, _CharT* __result)
{
typedef istreambuf_iterator<_CharT> __is_iterator_type;
typedef typename __is_iterator_type::traits_type traits_type;
typedef typename __is_iterator_type::streambuf_type streambuf_type;
typedef typename traits_type::int_type int_type;
if (__first._M_sbuf && !__last._M_sbuf)
{
streambuf_type* __sb = __first._M_sbuf;
int_type __c = __sb->sgetc();
while (!traits_type::eq_int_type(__c, traits_type::eof()))
{
const streamsize __n = __sb->egptr() - __sb->gptr();
if (__n > 1)
{
traits_type::copy(__result, __sb->gptr(), __n);
__sb->__safe_gbump(__n);
__result += __n;
__c = __sb->underflow();
}
else
{
*__result++ = traits_type::to_char_type(__c);
__c = __sb->snextc();
}
}
}
return __result;
}
template<typename _CharT>
typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
istreambuf_iterator<_CharT> >::__type
find(istreambuf_iterator<_CharT> __first,
istreambuf_iterator<_CharT> __last, const _CharT& __val)
{
typedef istreambuf_iterator<_CharT> __is_iterator_type;
typedef typename __is_iterator_type::traits_type traits_type;
typedef typename __is_iterator_type::streambuf_type streambuf_type;
typedef typename traits_type::int_type int_type;
const int_type __eof = traits_type::eof();
if (__first._M_sbuf && !__last._M_sbuf)
{
const int_type __ival = traits_type::to_int_type(__val);
streambuf_type* __sb = __first._M_sbuf;
int_type __c = __sb->sgetc();
while (!traits_type::eq_int_type(__c, __eof)
&& !traits_type::eq_int_type(__c, __ival))
{
streamsize __n = __sb->egptr() - __sb->gptr();
if (__n > 1)
{
const _CharT* __p = traits_type::find(__sb->gptr(),
__n, __val);
if (__p)
__n = __p - __sb->gptr();
__sb->__safe_gbump(__n);
__c = __sb->sgetc();
}
else
__c = __sb->snextc();
}
__first._M_c = __eof;
}
return __first;
}
template<typename _CharT, typename _Distance>
typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
void>::__type
advance(istreambuf_iterator<_CharT>& __i, _Distance __n)
{
if (__n == 0)
return;
__glibcxx_assert(__n > 0);
__glibcxx_requires_cond(!__i._M_at_eof(),
_M_message(__gnu_debug::__msg_inc_istreambuf)
._M_iterator(__i));
typedef istreambuf_iterator<_CharT> __is_iterator_type;
typedef typename __is_iterator_type::traits_type traits_type;
typedef typename __is_iterator_type::streambuf_type streambuf_type;
typedef typename traits_type::int_type int_type;
const int_type __eof = traits_type::eof();
streambuf_type* __sb = __i._M_sbuf;
while (__n > 0)
{
streamsize __size = __sb->egptr() - __sb->gptr();
if (__size > __n)
{
__sb->__safe_gbump(__n);
break;
}
__sb->__safe_gbump(__size);
__n -= __size;
if (traits_type::eq_int_type(__sb->underflow(), __eof))
{
__glibcxx_requires_cond(__n == 0,
_M_message(__gnu_debug::__msg_inc_istreambuf)
._M_iterator(__i));
break;
}
}
__i._M_c = __eof;
}
/// @} group iterators
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#endif
streambuf
debug.h
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:98
std::advance
_GLIBCXX17_CONSTEXPR void advance(_InputIterator &__i, _Distance __n)
A generalization of pointer arithmetic.
Definition: stl_iterator_base_funcs.h:202
std::basic_streambuf
The actual work of input and output (interface).
Definition: streambuf:123
std::basic_streambuf::sputn
streamsize sputn(const char_type *__s, streamsize __n)
Entry point for all single-character output functions.
Definition: streambuf:457
std::basic_streambuf::sbumpc
int_type sbumpc()
Getting the next character.
Definition: streambuf:323
std::basic_streambuf::sgetc
int_type sgetc()
Getting the next character.
Definition: streambuf:345
std::basic_streambuf::sputc
int_type sputc(char_type __c)
Entry point for all single-character output functions.
Definition: streambuf:431
std::basic_istream
Template class basic_istream.
Definition: istream:59
std::basic_ostream
Template class basic_ostream.
Definition: ostream:59
std::istreambuf_iterator
Provides input iterator semantics for streambufs.
Definition: streambuf_iterator.h:59
std::istreambuf_iterator::streambuf_type
basic_streambuf< _CharT, _Traits > streambuf_type
Public typedefs.
Definition: streambuf_iterator.h:67
std::istreambuf_iterator::operator++
istreambuf_iterator & operator++()
Advance the iterator. Calls streambuf.sbumpc().
Definition: streambuf_iterator.h:149
std::istreambuf_iterator::istreambuf_iterator
constexpr istreambuf_iterator() noexcept
Construct end of input stream iterator.
Definition: streambuf_iterator.h:107
std::istreambuf_iterator::istream_type
basic_istream< _CharT, _Traits > istream_type
Public typedefs.
Definition: streambuf_iterator.h:68
std::istreambuf_iterator::operator*
char_type operator*() const
Return the current character pointed to by iterator. This returns streambuf.sgetc()....
Definition: streambuf_iterator.h:133
std::istreambuf_iterator::equal
bool equal(const istreambuf_iterator &__b) const
Return true both iterators are end or both are not end.
Definition: streambuf_iterator.h:181
std::istreambuf_iterator::traits_type
_Traits traits_type
Public typedefs.
Definition: streambuf_iterator.h:65
std::istreambuf_iterator::istreambuf_iterator
istreambuf_iterator(istream_type &__s) noexcept
Construct start of input stream iterator.
Definition: streambuf_iterator.h:117
std::istreambuf_iterator::operator++
istreambuf_iterator operator++(int)
Advance the iterator. Calls streambuf.sbumpc().
Definition: streambuf_iterator.h:163
std::istreambuf_iterator::char_type
_CharT char_type
Public typedefs.
Definition: streambuf_iterator.h:64
std::istreambuf_iterator::istreambuf_iterator
istreambuf_iterator(streambuf_type *__s) noexcept
Construct start of streambuf iterator.
Definition: streambuf_iterator.h:121
std::istreambuf_iterator::int_type
_Traits::int_type int_type
Public typedefs.
Definition: streambuf_iterator.h:66
std::ostreambuf_iterator
Provides output iterator semantics for streambufs.
Definition: streambuf_iterator.h:222
std::ostreambuf_iterator::operator++
ostreambuf_iterator & operator++()
Return *this.
Definition: streambuf_iterator.h:274
std::ostreambuf_iterator::operator*
ostreambuf_iterator & operator*()
Return *this.
Definition: streambuf_iterator.h:264
std::ostreambuf_iterator::failed
bool failed() const noexcept
Return true if previous operator=() failed.
Definition: streambuf_iterator.h:279
std::ostreambuf_iterator::traits_type
_Traits traits_type
Public typedefs.
Definition: streambuf_iterator.h:228
std::ostreambuf_iterator::ostream_type
basic_ostream< _CharT, _Traits > ostream_type
Public typedefs.
Definition: streambuf_iterator.h:230
std::ostreambuf_iterator::streambuf_type
basic_streambuf< _CharT, _Traits > streambuf_type
Public typedefs.
Definition: streambuf_iterator.h:229
std::ostreambuf_iterator::operator=
ostreambuf_iterator & operator=(_CharT __c)
Write character to streambuf. Calls streambuf.sputc().
Definition: streambuf_iterator.h:254
std::ostreambuf_iterator::ostreambuf_iterator
ostreambuf_iterator(ostream_type &__s) noexcept
Construct output iterator from ostream.
Definition: streambuf_iterator.h:245
std::ostreambuf_iterator::operator++
ostreambuf_iterator & operator++(int)
Return *this.
Definition: streambuf_iterator.h:269
std::ostreambuf_iterator::char_type
_CharT char_type
Public typedefs.
Definition: streambuf_iterator.h:227
std::ostreambuf_iterator::ostreambuf_iterator
ostreambuf_iterator(streambuf_type *__s) noexcept
Construct output iterator from streambuf.
Definition: streambuf_iterator.h:249
std::iterator
Common iterator class.
Definition: stl_iterator_base_types.h:119