istream

C语言库函数的原型,有用的拿去

		return (*this);
		}

	_Myt& __CLR_OR_THIS_CALL operator>>(long double& _Val)
		{	// extract a long double
		ios_base::iostate _State = ios_base::goodbit;
		const sentry _Ok(*this);

		if (_Ok)
			{	// state okay, use facet to extract
			const _Nget& _Nget_fac = _USE(ios_base::getloc(), _Nget);
			_TRY_IO_BEGIN
			_Nget_fac.get(_Iter(_Myios::rdbuf()), _Iter(0),
				*this, _State, _Val);
			_CATCH_IO_END
			}

		_Myios::setstate(_State);
		return (*this);
		}

	_Myt& __CLR_OR_THIS_CALL operator>>(void *& _Val)
		{	// extract a void pointer
		ios_base::iostate _State = ios_base::goodbit;
		const sentry _Ok(*this);

		if (_Ok)
			{	// state okay, use facet to extract
			const _Nget& _Nget_fac = _USE(ios_base::getloc(), _Nget);

			_TRY_IO_BEGIN
			_Nget_fac.get(_Iter(_Myios::rdbuf()), _Iter(0),
				*this, _State, _Val);
			_CATCH_IO_END
			}

		_Myios::setstate(_State);
		return (*this);
		}

	_Myt& __CLR_OR_THIS_CALL operator>>(_Mysb *_Strbuf)
		{	// extract until end-of-file into a stream buffer
		ios_base::iostate _State = ios_base::goodbit;
		bool _Copied = false;
		const sentry _Ok(*this);

		if (_Ok && _Strbuf != 0)
			{	// state okay, extract characters
			_TRY_IO_BEGIN
			int_type _Meta = _Myios::rdbuf()->sgetc();

			for (; ; _Meta = _Myios::rdbuf()->snextc())
				if (_Traits::eq_int_type(_Traits::eof(), _Meta))
					{	// end of file, quit
					_State |= ios_base::eofbit;
					break;
					}
				else
					{	// got a character, insert it into buffer
					_TRY_BEGIN
						if (_Traits::eq_int_type(_Traits::eof(),
							_Strbuf->sputc(_Traits::to_char_type(_Meta))))
							break;
					_CATCH_ALL
						break;
					_CATCH_END
					_Copied = true;
					}
			_CATCH_IO_END
			}

		_Myios::setstate(!_Copied ? _State | ios_base::failbit : _State);
		return (*this);
		}

	int_type __CLR_OR_THIS_CALL get()
		{	// extract a metacharacter
		int_type _Meta = 0;
		ios_base::iostate _State = ios_base::goodbit;
		_Chcount = 0;
		const sentry _Ok(*this, true);

		if (!_Ok)
			_Meta = _Traits::eof();	// state not okay, return EOF
		else
			{	// state okay, extract a character
			_TRY_IO_BEGIN
			_Meta = _Myios::rdbuf()->sgetc();

			if (_Traits::eq_int_type(_Traits::eof(), _Meta))
				_State |= ios_base::eofbit | ios_base::failbit;	// end of file
			else
				{	// got a character, count it
				_Myios::rdbuf()->sbumpc();
				++_Chcount;
				}
			_CATCH_IO_END
			}

		_Myios::setstate(_State);
		return (_Meta);
		}

	_Myt& __CLR_OR_THIS_CALL get(_Elem *_Str, streamsize _Count)
		{	// get up to _Count characters into NTCS
		return (get(_Str, _Count, _Myios::widen('\n')));
		}

	_Myt& __CLR_OR_THIS_CALL get(_Elem *_Str,
		streamsize _Count, _Elem _Delim)
		{	// get up to _Count characters into NTCS, stop before _Delim
		_DEBUG_POINTER(_Str);
		ios_base::iostate _State = ios_base::goodbit;
		_Chcount = 0;
		const sentry _Ok(*this, true);

		if (_Ok && 0 < _Count)
			{	// state okay, extract characters
			_TRY_IO_BEGIN
			int_type _Meta = _Myios::rdbuf()->sgetc();

			for (; 0 < --_Count; _Meta = _Myios::rdbuf()->snextc())
				if (_Traits::eq_int_type(_Traits::eof(), _Meta))
					{	// end of file, quit
					_State |= ios_base::eofbit;
					break;
					}
				else if (_Traits::to_char_type(_Meta) == _Delim)
					break;	// got a delimiter, quit
				else
					{	// got a character, add it to string
					*_Str++ = _Traits::to_char_type(_Meta);
					++_Chcount;
					}
			_CATCH_IO_END
			}

		_Myios::setstate(_Chcount == 0
			? _State | ios_base::failbit : _State);
		*_Str = _Elem();	// add terminating null character
		return (*this);
		}

	_Myt& __CLR_OR_THIS_CALL get(_Elem& _Ch)
		{	// get a character
		int_type _Meta = get();
		if (!_Traits::eq_int_type(_Traits::eof(), _Meta))
			_Ch = _Traits::to_char_type(_Meta);
		return (*this);
		}

	_Myt& __CLR_OR_THIS_CALL get(_Mysb& _Strbuf)
		{	// extract up to newline and insert into stream buffer
		return (get(_Strbuf, _Myios::widen('\n')));
		}

	_Myt& __CLR_OR_THIS_CALL get(_Mysb& _Strbuf, _Elem _Delim)
		{	// extract up to delimiter and insert into stream buffer
		ios_base::iostate _State = ios_base::goodbit;
		_Chcount = 0;
		const sentry _Ok(*this, true);

		if (_Ok)
			{	// state okay, use facet to extract
			_TRY_IO_BEGIN
			int_type _Meta = _Myios::rdbuf()->sgetc();

			for (; ; _Meta = _Myios::rdbuf()->snextc())
				if (_Traits::eq_int_type(_Traits::eof(), _Meta))
					{	// end of file, quit
					_State |= ios_base::eofbit;
					break;
					}
				else
					{	// got a character, insert it into stream buffer
					_TRY_BEGIN
						_Elem _Ch = _Traits::to_char_type(_Meta);
						if (_Ch == _Delim
							|| _Traits::eq_int_type(_Traits::eof(),
								_Strbuf.sputc(_Ch)))
							break;
					_CATCH_ALL
						break;
					_CATCH_END
					++_Chcount;
					}
			_CATCH_IO_END
			}

		if (_Chcount == 0)
			_State |= ios_base::failbit;
		_Myios::setstate(_State);
		return (*this);
		}

	_Myt& __CLR_OR_THIS_CALL getline(_Elem *_Str, streamsize _Count)
		{	// get up to _Count characters into NTCS, discard newline
		return (getline(_Str, _Count, _Myios::widen('\n')));
		}

	_Myt& __CLR_OR_THIS_CALL getline(_Elem *_Str,
		streamsize _Count, _Elem _Delim)
		{	// get up to _Count characters into NTCS, discard _Delim
		_DEBUG_POINTER(_Str);
		ios_base::iostate _State = ios_base::goodbit;
		_Chcount = 0;
		const sentry _Ok(*this, true);

		if (_Ok && 0 < _Count)
			{	// state okay, use facet to extract
			int_type _Metadelim = _Traits::to_int_type(_Delim);

			_TRY_IO_BEGIN
			int_type _Meta = _Myios::rdbuf()->sgetc();

			for (; ; _Meta = _Myios::rdbuf()->snextc())
				if (_Traits::eq_int_type(_Traits::eof(), _Meta))
					{	// end of file, quit
					_State |= ios_base::eofbit;
					break;
					}
				else if (_Meta == _Metadelim)
					{	// got a delimiter, discard it and quit
					++_Chcount;
					_Myios::rdbuf()->sbumpc();
					break;
					}
				else if (--_Count <= 0)
					{	// buffer full, quit
					_State |= ios_base::failbit;
					break;
					}
				else
					{	// got a character, add it to string
					++_Chcount;
					*_Str++ = _Traits::to_char_type(_Meta);
					}
			_CATCH_IO_END
			}

		*_Str = _Elem();	// add terminating null character
		_Myios::setstate(_Chcount == 0 ? _State | ios_base::failbit : _State);
		return (*this);
		}

	_Myt& __CLR_OR_THIS_CALL ignore(streamsize _Count = 1,
		int_type _Metadelim = _Traits::eof())
		{	// ignore up to _Count characters, discarding delimiter
		ios_base::iostate _State = ios_base::goodbit;
		_Chcount = 0;
		const sentry _Ok(*this, true);

		if (_Ok && 0 < _Count)
			{	// state okay, use facet to extract
			_TRY_IO_BEGIN
			for (; ; )
				{	// get a metacharacter if more room in buffer
				int_type _Meta;
				if (_Count != INT_MAX && --_Count < 0)
					break;	// buffer full, quit
				else if (_Traits::eq_int_type(_Traits::eof(),
					_Meta = _Myios::rdbuf()->sbumpc()))
					{	// end of file, quit
					_State |= ios_base::eofbit;
					break;
					}
				else
					{	// got a character, count it
					++_Chcount;
					if (_Meta == _Metadelim)
						break;	// got a delimiter, quit
					}
				}
			_CATCH_IO_END
			}

		_Myios::setstate(_State);
		return (*this);
		}

	_Myt& __CLR_OR_THIS_CALL read(_Elem *_Str, streamsize _Count)
		{	// read up to _Count characters into buffer
		_DEBUG_POINTER(_Str);
		ios_base::iostate _State = ios_base::goodbit;
		_Chcount = 0;
		const sentry _Ok(*this, true);

		if (_Ok)
			{	// state okay, use facet to extract
			_TRY_IO_BEGIN
			const streamsize _Num = _Myios::rdbuf()->sgetn(_Str, _Count);
			_Chcount += _Num;
			if (_Num != _Count)
				_State |= ios_base::eofbit | ios_base::failbit;	// short read
			_CATCH_IO_END
			}

		_Myios::setstate(_State);
		return (*this);
		}

	streamsize __CLR_OR_THIS_CALL readsome(_Elem *_Str,
		streamsize _Count)
		{	// read up to _Count characters into buffer, without blocking
		_DEBUG_POINTER(_Str);
		ios_base::iostate _State = ios_base::goodbit;
		_Chcount = 0;
		const sentry _Ok(*this, true);
		streamsize _Num;

		if (!_Ok)
			_State |= ios_base::failbit;	// no buffer, fail
		else if ((_Num = _Myios::rdbuf()->in_avail()) < 0)
			_State |= ios_base::eofbit;	// no characters available
		else if (0 < _Num)
			read(_Str, _Num < _Count ? _Num : _Count);	// read available

		_Myios::setstate(_State);
		return (gcount());
		}

	int_type __CLR_OR_THIS_CALL peek()
		{	// return next character, unconsumed
		ios_base::iostate _State = ios_base::goodbit;
		_Chcount = 0;
		int_type _Meta = 0;
		const sentry _Ok(*this, true);

		if (!_Ok)
			_Meta = _Traits::eof();	// state not okay, return EOF
		else
			{	// state okay, read a character
			_TRY_IO_BEGIN
			if (_Traits::eq_int_type(_Traits::eof(),
				_Meta = _Myios::rdbuf()->sgetc()))
				_State |= ios_base::eofbit;
			_CATCH_IO_END
			}

		_Myios::setstate(_State);
		return (_Meta);
		}

	_Myt& __CLR_OR_THIS_CALL putback(_Elem _Ch)
		{	// put back a character
		ios_base::iostate _State = ios_base::goodbit;
		_Chcount = 0;
		const sentry _Ok(*this, true);

		if (_Ok)
			{	// state okay, put character back
			_TRY_IO_BEGIN
			if (_Traits::eq_int_type(_Traits::eof(),
				_Myios::rdbuf()->sputbackc(_Ch)))
				_State |= ios_base::badbit;
			_CATCH_IO_END
			}

		_Myios::setstate(_State);
		return (*this);
		}

	_Myt& __CLR_OR_THIS_CALL unget()
		{	// put back last read character
		ios_base::iostate _State = ios_base::goodbit;
		_Chcount = 0;
		const sentry _Ok(*this, true);

		if (_Ok)
			{	// state okay, use facet to extract
			_TRY_IO_BEGIN
			if (_Traits::eq_int_type(_Traits::eof(),
				_Myios::rdbuf()->sungetc()))
				_State |= ios_base::badbit;
			_CATCH_IO_END
			}

		_Myios::setstate(_State);
		return (*this);
		}

	streamsize __CLR_OR_THIS_CALL gcount() const
		{	// get count from last extraction
		return (_Chcount);
		}

	int __CLR_OR_THIS_CALL sync()
		{	// synchronize with input source
		ios_base::iostate _State = ios_base::goodbit;
		int _Ans;

		if (_Myios::rdbuf() == 0)
			_Ans = -1;	// no buffer, fail
		else if (_Myios::rdbuf()->pubsync() == -1)
			{	// stream buffer sync failed, fail
			_State |= ios_base::badbit;
			_Ans = -1;
			}
		else
			_Ans = 0;	// success

		_Myios::setstate(_State);
		return (_Ans);
		}

	_Myt& __CLR_OR_THIS_CALL seekg(pos_type _Pos)
		{	// set input stream position to _Pos
		if (!ios_base::fail()
			&& (off_type)_Myios::rdbuf()->pubseekpos(_Pos,
				ios_base::in) == _BADOFF)
			_Myios::setstate(ios_base::failbit);
		return (*this);
		}

	_Myt& __CLR_OR_THIS_CALL seekg(off_type _Off, ios_base::seekdir _Way)
		{	// change input stream position by _Off, according to _Way
		if (!ios_base::fail()
			&& (off_type)_Myios::rdbuf()->pubseekoff(_Off, _Way,
				ios_base::in) == _BADOFF)
			_Myios::setstate(ios_base::failbit);
		return (*this);
		}

	pos_type __CLR_OR_THIS_CALL tellg()
		{	// return input stream position
		if (!ios_base::fail())
			return (_Myios::rdbuf()->pubseekoff(0,
				ios_base::cur, ios_base::in));
		else
			return (pos_type(_BADOFF));
		}

private:
	streamsize _Chcount;	// the character count
	};

	// basic_istream TEMPLATE OPERATORS
template<class _Elem,