strstream

C语言库函数的原型,有用的拿去

// strstream standard header
#pragma once
#ifndef _STRSTREAM_
#define _STRSTREAM_
#ifndef RC_INVOKED
#include <istream>

 #pragma pack(push,_CRT_PACKING)
 #pragma warning(push,3)

 #pragma push_macro("new")
 #undef new

_STD_BEGIN
		// CLASS strstreambuf
class strstreambuf
	: public streambuf
	{	// stream buffer associated with static or allocated character array
public:
	typedef strstreambuf _Myt;
	typedef streambuf _Mysb;
	enum
		{	// constants for bits in stream state
		_Allocated = 1,	// set if character array storage has been allocated
		_Constant = 2,	// set if character array nonmutable
		_Dynamic = 4,	// set if character array length grows on demand
		_Frozen = 8};	// set if character array ownership given away
	typedef int _Strstate;

	explicit __CLR_OR_THIS_CALL strstreambuf(streamsize _Count = 0)
		{	// construct with empty character array, suggested initial size
		_Init(_Count);
		}

	__CLR_OR_THIS_CALL strstreambuf(void *(__CLRCALL_OR_CDECL *_Allocfunc)(size_t),
		void (__CLRCALL_OR_CDECL *_Freefunc)(void *))
		{	// construct with empty character array, allocation functions
		_Init();
		_Palloc = _Allocfunc;
		_Pfree = _Freefunc;
		}

	__CLR_OR_THIS_CALL strstreambuf(_In_opt_z_ char *_Getptr,
		streamsize _Count,
		_In_opt_z_ char *_Putptr = 0)
		{	// construct with [_Getptr, _Getptr + _Count), possibly mutable
		_Init(_Count, _Getptr, _Putptr);
		}

	__CLR_OR_THIS_CALL strstreambuf(_In_z_ const char *_Getptr,
		streamsize _Count)
		{	// construct with [_Getptr, _Getptr + _Count), nonmutable
		_Init(_Count, (char *)_Getptr, 0, _Constant);
		}

  #pragma warning(push)
  #pragma warning(disable: 6054)

	__CLR_OR_THIS_CALL strstreambuf(_In_opt_z_ unsigned char *_Getptr,
		streamsize _Count,
		_In_opt_z_ unsigned char *_Putptr = 0)
		{	// construct with [_Getptr, _Getptr + _Count), possibly mutable
		_Init(_Count, (char *)_Getptr, (char *)_Putptr);
		}

	__CLR_OR_THIS_CALL strstreambuf(_In_opt_z_ const unsigned char *_Getptr,
		streamsize _Count)
		{	// construct with [_Getptr, _Getptr + _Count), nonmutable
		_Init(_Count, (char *)_Getptr, 0, _Constant);
		}

  #pragma warning(pop)

	__CLR_OR_THIS_CALL strstreambuf(_Myt&& _Right)
		{	// construct by moving _Right
		_Init();
		_Assign_rv(_STD forward<_Myt>(_Right));
		}

	_Myt& __CLR_OR_THIS_CALL operator=(_Myt&& _Right)
		{	// assign by moving _Right
		_Assign_rv(_STD forward<_Myt>(_Right));
		return (*this);
		}

	void __CLR_OR_THIS_CALL _Assign_rv(_Myt&& _Right)
		{	// assign by moving _Right
		if (this != &_Right)
			{	// different, worth moving
			_Tidy();
			this->swap(_Right);
			}
		}

	void __CLR_OR_THIS_CALL swap(_Myt& _Right)
		{	// swap with _Right
		if (this != &_Right)
			{	// different, worth swapping
			_Mysb::swap(_Right);
			_STD swap(_Minsize, _Right._Minsize);
			_STD swap(_Pendsave, _Right._Pendsave);
			_STD swap(_Seekhigh, _Right._Seekhigh);
			_STD swap(_Strmode, _Right._Strmode);
			_STD swap(_Palloc, _Right._Palloc);
			_STD swap(_Pfree, _Right._Pfree);
			}
		}

	void __CLR_OR_THIS_CALL swap(_Myt&& _Right)
		{	// swap with _Right
		_Assign_rv(_STD forward<_Myt>(_Right));
		}

	virtual __CLR_OR_THIS_CALL ~strstreambuf()
		{	// destroy a strstreambuf
		_Tidy();
		}

	void __CLR_OR_THIS_CALL freeze(bool _Freezeit = true)
		{	// freeze or unfreeze writing
		if (_Freezeit && !(_Strmode & _Frozen))
			{	// disable writing
			_Strmode |= _Frozen;
			_Pendsave = epptr();
			setp(pbase(), pptr(), eback());
			}
		else if (!_Freezeit && _Strmode & _Frozen)
			{	// re-enable writing
			_Strmode &= ~_Frozen;
			setp(pbase(), pptr(), _Pendsave);
			}
		}

	char *__CLR_OR_THIS_CALL str()
		{	// freeze and return pointer to character array
		freeze();
		return (gptr());
		}

	streamsize __CLR_OR_THIS_CALL pcount() const
		{	// return size of writable character array
		return (pptr() == 0 ? 0 : (streamsize)(pptr() - pbase()));
		}

	__CLR_OR_THIS_CALL strstreambuf(_In_opt_z_ signed char *_Getptr,
		streamsize _Count,
		_In_opt_z_ signed char *_Putptr = 0)
		{	// construct with [_Getptr, _Getptr + _Count), possibly mutable
		_Init(_Count, (char *)_Getptr, (char *)_Putptr);
		}

	__CLR_OR_THIS_CALL strstreambuf(const signed char *_Getptr,
		streamsize _Count)
		{	// construct with [_Getptr, _Getptr + _Count), nonmutable
		_Init(_Count, (char *)_Getptr, 0, _Constant);
		}

	void clear()
		{	// free any allocated storage
		_Tidy();
		}

protected:
	virtual int __CLR_OR_THIS_CALL overflow(int _Meta = EOF)
		{	// try to extend write area
		if (_Meta == EOF)
			return (0);	// nothing to write
		else if (pptr() != 0 && pptr() < epptr())
			return ((unsigned char)(*_Pninc() = (char)_Meta));
		else if (!(_Strmode & _Dynamic)
			|| _Strmode & (_Constant | _Frozen))
			return (EOF);	// can't extend
		else
			{	// okay to extend
			int _Oldsize = gptr() == 0 ? 0 : (int)(epptr() - eback());
			int _Newsize = _Oldsize;
			int _Inc = _Newsize / 2 < _Minsize
				? _Minsize : _Newsize / 2;	// grow by 50 per cent if possible
			_Minsize = _MINSIZE;	// back to default for future growth
			char *_Ptr = 0;

			while (0 < _Inc && INT_MAX - _Inc < _Newsize)
				_Inc /= 2;	// reduce growth increment if too big
			if (0 < _Inc)
				{	// room to grow, increase size
				_Newsize += _Inc;
				_Ptr = _Palloc != 0 ? (char *)(*_Palloc)(_Newsize)
					: _NEW_CRT char[_Newsize];
				}
			if (_Ptr == 0)
				return (EOF);	// couldn't grow, return failure

			if (0 < _Oldsize)
				_CSTD memcpy(_Ptr, eback(), _Oldsize);	// copy existing
			if (!(_Strmode & _Allocated))
				;	// no buffer to free
			else if (_Pfree != 0)
				(*_Pfree)(eback());	// free with function call
			else
				_DELETE_CRT_VEC(eback());	// free by deleting array

			_Strmode |= _Allocated;
			if (_Oldsize == 0)
				{	// set up new buffer
				_Seekhigh = _Ptr;
				setp(_Ptr, _Ptr + _Newsize);
				setg(_Ptr, _Ptr, _Ptr);
				}
			else
				{	// revise old pointers
				_Seekhigh = _Seekhigh - eback() + _Ptr;
				setp(pbase() - eback() + _Ptr, pptr() - eback() + _Ptr,
					_Ptr + _Newsize);
				setg(_Ptr, gptr() - eback() + _Ptr, pptr() + 1);
				}

			return ((unsigned char)(*_Pninc() = (char)_Meta));
			}
		}

	virtual int __CLR_OR_THIS_CALL pbackfail(int _Meta = EOF)
		{	// try to putback a character
		if (gptr() == 0 || gptr() <= eback() || _Meta != EOF
				&& (unsigned char)_Meta != (unsigned char)gptr()[-1]
				&& _Strmode & _Constant)
			return (EOF);	// can't put it back
		else
			{	// safe to back up
			gbump(-1);
			if (_Meta != EOF && *gptr() != (char)_Meta)
				*gptr() = (char)_Meta;
			return (_Meta == EOF ? 0 : (unsigned char)_Meta);
			}
		}

	virtual int __CLR_OR_THIS_CALL underflow()
		{	// read if read position available
		if (gptr() == 0)
			return (EOF);	// no read buffer
		else if (gptr() < egptr())
			return ((unsigned char)*gptr());	// char in buffer, read it
		else if (pptr() == 0 || pptr() <= gptr() && _Seekhigh <= gptr())
			return (EOF);	// no write buffer to read
		else
			{	// update _Seekhigh and expand read region
			if (_Seekhigh < pptr())
				_Seekhigh = pptr();
			setg(eback(), gptr(), _Seekhigh);
			return ((unsigned char)*gptr());
			}
		}

	virtual streampos __CLR_OR_THIS_CALL seekoff(streamoff _Off_arg,
		ios_base::seekdir _Way,
		ios_base::openmode _Which =
			ios_base::in | ios_base::out)
		{	// seek by specified offset
		int _Off = (int)_Off_arg;

		if (pptr() != 0 && (int)(_Seekhigh - pptr()) < 0)	// sic
			_Seekhigh = pptr();	// update high water mark

		if (_Which & ios_base::in && gptr() != 0)
			{	// set input (and maybe output) pointer
			if (_Way == ios_base::end)
				_Off += (int)(_Seekhigh - eback());	// seek from end
			else if (_Way == ios_base::cur
				&& !(_Which & ios_base::out))
				_Off += (int)(gptr() - eback());	// seek from current
			else if (_Way != ios_base::beg || _Off == (int)_BADOFF)
				_Off = (int)_BADOFF;	// invalid seek
			if (0 <= _Off && _Off <= (int)(_Seekhigh - eback()))
				{	// seek from beginning, set one or two pointers
				gbump(_Off - (int)(gptr() - eback()));
				if (_Which & ios_base::out && pptr() != 0)
					setp(pbase(), gptr(), epptr());
				}
			else
				_Off = (int)_BADOFF;	// invalid seek from beginning
			}
		else if (_Which & ios_base::out && pptr() != 0)
			{	// set only output pointer
			if (_Way == ios_base::end)
				_Off += (int)(_Seekhigh - eback());	// seek from end
			else if (_Way == ios_base::cur)
				_Off += (int)(pptr() - eback());	// seek from current
			else if (_Way != ios_base::beg || _Off == (int)_BADOFF)
				_Off = (int)_BADOFF;	// invalid seek
			if (0 <= _Off && _Off <= (int)(_Seekhigh - eback()))
				pbump(_Off - (int)(pptr() - eback()));	// seek from beginning
			else
				_Off = (int)_BADOFF;	// invalid seek from beginning
			}
		else
			_Off = (int)_BADOFF;	// nothing to set
		return (streampos((streamoff)_Off));
		}

	virtual streampos __CLR_OR_THIS_CALL seekpos(streampos _Sp,
		ios_base::openmode _Which=
			ios_base::in | ios_base::out)
		{	// seek to memorized position
		int _Off = (int)(streamoff)_Sp;

		if (pptr() != 0 && (int)(_Seekhigh - pptr()) < 0)	// sic
			_Seekhigh = pptr();	// update high water mark

		if (_Off == (int)_BADOFF)
			;	// invalid seek
		else if (_Which & ios_base::in && gptr() != 0)
			{	// set input (and maybe output) pointer
			if (0 <= _Off && _Off <= (int)(_Seekhigh - eback()))
				{	// set valid offset
				gbump(_Off - (int)(gptr() - eback()));
				if (_Which & ios_base::out && pptr() != 0)
					setp(pbase(), gptr(), epptr());
				}
			else
				_Off = (int)_BADOFF;	// offset invalid, don't seek
			}
		else if (_Which & ios_base::out && pptr() != 0)
			{	// set output pointer
			if (0 <= _Off && _Off <= (int)(_Seekhigh - eback()))
				pbump(_Off - (int)(pptr() - eback()));	// seek from beginning
			else
				_Off = (int)_BADOFF;	// offset invalid, don't seek
			}
		else
			_Off = (int)_BADOFF;	// nothing to set
		return (streampos((streamoff)_Off));
		}

	void __CLR_OR_THIS_CALL _Init(streamsize _Count = 0,
		char *_Gp = 0,
		char *_Pp = 0,
		_Strstate _Mode = (_Strstate)0)
		{	// initialize with possibly static buffer
		streambuf::_Init();
		_Minsize = _MINSIZE;
		_Pendsave = 0;
		_Seekhigh = 0;
		_Palloc = 0;
		_Pfree = 0;
		_Strmode = _Mode;

		if (_Gp == 0)
			{	// make dynamic
			_Strmode |= _Dynamic;
			if (_Minsize < _Count)
				_Minsize = (int)_Count;
			}
		else
			{	// make static
			size_t _Size = _Count < 0 ? INT_MAX
				: _Count == 0 ? _CSTD strlen(_Gp)
				: (size_t)_Count;
			_Seekhigh = _Gp + _Size;

			if (_Pp == 0)
				setg(_Gp, _Gp, _Gp + _Size);	// set read pointers only
			else
				{	// make writable too
				if (_Pp < _Gp)
					_Pp = _Gp;
				else if (_Gp + _Size < _Pp)
					_Pp = _Gp + _Size;
				setp(_Pp, _Gp + _Size);
				setg(_Gp, _Gp, _Pp);
				}
			}
		}

	void __CLR_OR_THIS_CALL _Tidy()
		{	// free any allocated storage
		if ((_Strmode & (_Allocated | _Frozen)) != _Allocated)