272 lines
7.2 KiB
C++
272 lines
7.2 KiB
C++
// strstreambuf -- strstreambuf basic members
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#include <climits>
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#include <cstdlib>
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#include <cstring>
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#include <strstream>
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#include <xdebug>
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#pragma warning(disable:4244 4097)
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_STD_BEGIN
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_CRTIMP2 istrstream::~istrstream()
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{ // destroy an istrstream
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}
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_CRTIMP2 ostrstream::ostrstream(char *ptr, streamsize count,
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ios_base::openmode mode)
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: ostream(&_Mysb),
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_Mysb(ptr, count, ptr == 0 || (mode & app) == 0 ? ptr : ptr + strlen(ptr))
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{ // construct with [ptr, ptr + count)
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}
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_CRTIMP2 ostrstream::~ostrstream()
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{ // destroy an ostrstream
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}
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_CRTIMP2 strstream::strstream(char *ptr, streamsize count,
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ios_base::openmode mode)
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: iostream(&_Mysb),
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_Mysb(ptr, count, ptr == 0 || (mode & app) == 0 ? ptr : ptr + strlen(ptr))
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{ // construct with [ptr, ptr + count)
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}
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_CRTIMP2 strstream::~strstream()
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{ // destroy a strstream
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}
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_CRTIMP2 strstreambuf::~strstreambuf()
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{ // destroy a strstreambuf
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_Tidy();
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}
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_CRTIMP2 void strstreambuf::freeze(bool freezeit)
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{ // freeze or unfreeze writing
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if (freezeit && !(_Strmode & _Frozen))
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{ // disable writing
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_Strmode |= _Frozen;
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_Pendsave = epptr();
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setp(pbase(), pptr(), eback());
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}
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else if (!freezeit && _Strmode & _Frozen)
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{ // re-enable writing
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_Strmode &= ~_Frozen;
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setp(pbase(), pptr(), _Pendsave);
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}
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}
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_CRTIMP2 int strstreambuf::overflow(int meta)
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{ // try to extend write area
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if (meta == EOF)
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return (0); // nothing to write
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else if (pptr() != 0 && pptr() < epptr())
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return ((unsigned char)(*_Pninc() = meta)); // room in buffer
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else if (!(_Strmode & _Dynamic)
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|| _Strmode & (_Constant | _Frozen))
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return (EOF); // can't extend
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else
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{ // okay to extend
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int oldsize = gptr() == 0 ? 0 : epptr() - eback();
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int newsize = oldsize;
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int inc = newsize / 2 < _Minsize
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? _Minsize : newsize / 2; // grow by 50 per cent if possible
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_Minsize = _MINSIZE; // back to default for future growth
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char *ptr = 0;
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while (0 < inc && INT_MAX - inc < newsize)
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inc /= 2; // reduce growth increment if too big
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if (0 < inc)
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{ // room to grow, increase size
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newsize += inc;
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ptr = _Palloc != 0 ? (char *)(*_Palloc)(newsize)
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: _NEW_CRT char[newsize];
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}
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if (ptr == 0)
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return (EOF); // couldn't grow, return failure
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if (0 < oldsize)
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memcpy(ptr, eback(), oldsize); // copy existing buffer
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if (!(_Strmode & _Allocated))
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; // no buffer to free
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else if (_Pfree != 0)
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(*_Pfree)(eback()); // free with function call
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else
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_DELETE_CRT_VEC(eback()); // free by deleting array
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_Strmode |= _Allocated;
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if (oldsize == 0)
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{ // set up new buffer
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_Seekhigh = ptr;
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setp(ptr, ptr + newsize);
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setg(ptr, ptr, ptr);
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}
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else
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{ // revise old pointers
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_Seekhigh = _Seekhigh - eback() + ptr;
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setp(pbase() - eback() + ptr, pptr() - eback() + ptr,
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ptr + newsize);
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setg(ptr, gptr() - eback() + ptr, pptr() + 1);
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}
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return ((unsigned char)(*_Pninc() = meta));
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}
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}
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_CRTIMP2 int strstreambuf::pbackfail(int meta)
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{ // try to putback a character
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if (gptr() == 0 || gptr() <= eback() || meta != EOF
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&& (unsigned char)meta != (unsigned char)gptr()[-1]
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&& _Strmode & _Constant)
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return (EOF); // can't put it back
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else
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{ // safe to back up
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gbump(-1);
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return (meta == EOF ? 0 : (unsigned char)(*gptr() = meta));
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}
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}
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_CRTIMP2 int strstreambuf::underflow()
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{ // read if read position available
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if (gptr() == 0)
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return (EOF); // no read buffer
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else if (gptr() < egptr())
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return ((unsigned char)*gptr()); // char in buffer, read it
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else if (pptr() == 0 || pptr() <= gptr() && _Seekhigh <= gptr())
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return (EOF); // no write buffer to read
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else
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{ // update _Seekhigh and expand read region
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if (_Seekhigh < pptr())
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_Seekhigh = pptr();
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setg(eback(), gptr(), _Seekhigh);
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return ((unsigned char)*gptr());
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}
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}
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_CRTIMP2 streampos strstreambuf::seekoff(streamoff off,
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ios_base::seekdir way, ios_base::openmode which)
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{ // seek by specified offset
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if (pptr() != 0 && _Seekhigh < pptr())
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_Seekhigh = pptr(); // update high water mark
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if (which & ios_base::in && gptr() != 0)
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{ // set input (and maybe output) pointer
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if (way == ios_base::end)
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off += _Seekhigh - eback(); // seek from end
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else if (way == ios_base::cur
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&& !(which & ios_base::out))
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off += gptr() - eback(); // seek from current position
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else if (way != ios_base::beg || off == _BADOFF)
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off = _BADOFF; // invalid seek
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if (0 <= off && off <= _Seekhigh - eback())
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{ // seek from beginning, set one or two pointers
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gbump(eback() - gptr() + off);
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if (which & ios_base::out && pptr() != 0)
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setp(pbase(), gptr(), epptr());
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}
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else
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off = _BADOFF; // invalid seek from beginning
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}
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else if (which & ios_base::out && pptr() != 0)
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{ // set only output pointer
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if (way == ios_base::end)
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off += _Seekhigh - eback(); // seek from end
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else if (way == ios_base::cur)
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off += pptr() - eback(); // seek from current position
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else if (way != ios_base::beg || off == _BADOFF)
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off = _BADOFF; // invalid seek
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if (0 <= off && off <= _Seekhigh - eback())
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pbump(eback() - pptr() + off); // seek from beginning
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else
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off = _BADOFF; // invalid seek from beginning
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}
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else // nothing to set
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off = _BADOFF;
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return (streampos(off));
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}
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_CRTIMP2 streampos strstreambuf::seekpos(streampos sp,
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ios_base::openmode which)
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{ // seek to memorized position
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streamoff off = (streamoff)sp;
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if (pptr() != 0 && _Seekhigh < pptr())
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_Seekhigh = pptr(); // update high water mark
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if (off == _BADOFF)
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; // invalid seek
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else if (which & ios_base::in && gptr() != 0)
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{ // set input (and maybe output) pointer
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if (0 <= off && off <= _Seekhigh - eback())
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{ // set valid offset
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gbump(eback() - gptr() + off);
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if (which & ios_base::out && pptr() != 0)
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setp(pbase(), gptr(), epptr());
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}
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else
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off = _BADOFF; // offset invalid, don't seek
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}
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else if (which & ios_base::out && pptr() != 0)
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{ // set output pointer
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if (0 <= off && off <= _Seekhigh - eback())
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pbump(eback() - pptr() + off);
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else
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off = _BADOFF; // offset invalid, don't seek
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}
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else // nothing to set
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off = _BADOFF;
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return (streampos(off));
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}
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_CRTIMP2 void strstreambuf::_Init(streamsize count, char *gp, char *pp,
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_Strstate mode)
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{ // initialize with possibly static buffer
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streambuf::_Init();
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_Minsize = _MINSIZE;
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_Pendsave = 0;
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_Seekhigh = 0;
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_Palloc = 0;
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_Pfree = 0;
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_Strmode = mode;
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if (gp == 0)
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{ // make dynamic
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_Strmode |= _Dynamic;
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if (_Minsize < count)
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_Minsize = count;
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}
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else
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{ // make static
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int size = count < 0 ? INT_MAX : count == 0 ? (int)strlen(gp) : count;
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_Seekhigh = gp + size;
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if (pp == 0)
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setg(gp, gp, gp + size); // set read pointers only
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else
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{ // make writable too
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if (pp < gp)
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pp = gp;
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else if (gp + size < pp)
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pp = gp + size;
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setp(pp, gp + size);
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setg(gp, gp, pp);
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}
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}
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}
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_CRTIMP2 void strstreambuf::_Tidy()
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{ // free any allocated storage
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if ((_Strmode & (_Allocated | _Frozen)) != _Allocated)
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; // no buffer to free
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else if (_Pfree != 0)
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(*_Pfree)(eback()); // free with function call
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else
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_DELETE_CRT_VEC(eback()); // free by deleting array
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_Seekhigh = 0;
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_Strmode &= ~(_Allocated | _Frozen);
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}
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_STD_END
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/*
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* Copyright (c) 1992-2001 by P.J. Plauger. ALL RIGHTS RESERVED.
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* Consult your license regarding permissions and restrictions.
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V3.10:0009 */
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