stream_iterator.h
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// Stream iterators
// Copyright (C) 2001-2013 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/stream_iterator.h
* This is an internal header file, included by other library headers.
* Do not attempt to use it directly. @headername{iterator}
*/
#ifndef _STREAM_ITERATOR_H
#define _STREAM_ITERATOR_H 1
#pragma GCC system_header
#include <debug/debug.h>
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
/**
* @addtogroup iterators
* @{
*/
/// Provides input iterator semantics for streams.
template<typename _Tp, typename _CharT = char,
typename _Traits = char_traits<_CharT>, typename _Dist = ptrdiff_t>
class istream_iterator
: public iterator<input_iterator_tag, _Tp, _Dist, const _Tp*, const _Tp&>
{
public:
typedef _CharT char_type;
typedef _Traits traits_type;
typedef basic_istream<_CharT, _Traits> istream_type;
private:
istream_type* _M_stream;
_Tp _M_value;
bool _M_ok;
public:
/// Construct end of input stream iterator.
_GLIBCXX_CONSTEXPR istream_iterator()
: _M_stream(0), _M_value(), _M_ok(false) {}
/// Construct start of input stream iterator.
istream_iterator(istream_type& __s)
: _M_stream(&__s)
{ _M_read(); }
istream_iterator(const istream_iterator& __obj)
: _M_stream(__obj._M_stream), _M_value(__obj._M_value),
_M_ok(__obj._M_ok)
{ }
const _Tp&
operator*() const
{
__glibcxx_requires_cond(_M_ok,
_M_message(__gnu_debug::__msg_deref_istream)
._M_iterator(*this));
return _M_value;
}
const _Tp*
operator->() const { return &(operator*()); }
istream_iterator&
operator++()
{
__glibcxx_requires_cond(_M_ok,
_M_message(__gnu_debug::__msg_inc_istream)
._M_iterator(*this));
_M_read();
return *this;
}
istream_iterator
operator++(int)
{
__glibcxx_requires_cond(_M_ok,
_M_message(__gnu_debug::__msg_inc_istream)
._M_iterator(*this));
istream_iterator __tmp = *this;
_M_read();
return __tmp;
}
bool
_M_equal(const istream_iterator& __x) const
{ return (_M_ok == __x._M_ok) && (!_M_ok || _M_stream == __x._M_stream); }
private:
void
_M_read()
{
_M_ok = (_M_stream && *_M_stream) ? true : false;
if (_M_ok)
{
*_M_stream >> _M_value;
_M_ok = *_M_stream ? true : false;
}
}
};
/// Return true if x and y are both end or not end, or x and y are the same.
template<typename _Tp, typename _CharT, typename _Traits, typename _Dist>
inline bool
operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __y)
{ return __x._M_equal(__y); }
/// Return false if x and y are both end or not end, or x and y are the same.
template <class _Tp, class _CharT, class _Traits, class _Dist>
inline bool
operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __y)
{ return !__x._M_equal(__y); }
/**
* @brief Provides output iterator semantics for streams.
*
* This class provides an iterator to write to an ostream. The type Tp is
* the only type written by this iterator and there must be an
* operator<<(Tp) defined.
*
* @tparam _Tp The type to write to the ostream.
* @tparam _CharT The ostream char_type.
* @tparam _Traits The ostream char_traits.
*/
template<typename _Tp, typename _CharT = char,
typename _Traits = char_traits<_CharT> >
class ostream_iterator
: public iterator<output_iterator_tag, void, void, void, void>
{
public:
//@{
/// Public typedef
typedef _CharT char_type;
typedef _Traits traits_type;
typedef basic_ostream<_CharT, _Traits> ostream_type;
//@}
private:
ostream_type* _M_stream;
const _CharT* _M_string;
public:
/// Construct from an ostream.
ostream_iterator(ostream_type& __s) : _M_stream(&__s), _M_string(0) {}
/**
* Construct from an ostream.
*
* The delimiter string @a c is written to the stream after every Tp
* written to the stream. The delimiter is not copied, and thus must
* not be destroyed while this iterator is in use.
*
* @param __s Underlying ostream to write to.
* @param __c CharT delimiter string to insert.
*/
ostream_iterator(ostream_type& __s, const _CharT* __c)
: _M_stream(&__s), _M_string(__c) { }
/// Copy constructor.
ostream_iterator(const ostream_iterator& __obj)
: _M_stream(__obj._M_stream), _M_string(__obj._M_string) { }
/// Writes @a value to underlying ostream using operator<<. If
/// constructed with delimiter string, writes delimiter to ostream.
ostream_iterator&
operator=(const _Tp& __value)
{
__glibcxx_requires_cond(_M_stream != 0,
_M_message(__gnu_debug::__msg_output_ostream)
._M_iterator(*this));
*_M_stream << __value;
if (_M_string) *_M_stream << _M_string;
return *this;
}
ostream_iterator&
operator*()
{ return *this; }
ostream_iterator&
operator++()
{ return *this; }
ostream_iterator&
operator++(int)
{ return *this; }
};
// @} group iterators
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#endif