//set a new position
//if going too much back, restart the iterator
streampos StringIteratorStreamBuf::seekpos ( streampos sp, ios_base::openmode which )
{
if(!(which & ios_base::in))
return -1;
if(sp < begin_offset)
{
setg(eback(), eback(), egptr());
pbackfail(EOF);
if(sp < begin_offset)
{
//restart the iterator
if(!reset())
return -1;
buffer[0].resize(0);
buffer[1].resize(0);
current_buffer = last_buffer = 0;
begin_offset = 0;
is_eof = false;
setg(NULL, NULL, NULL);
}
}
while(sp >= (begin_offset+(streamoff)buffer[current_buffer].length()))
{
if(underflow() == EOF)
{
if(sp == (begin_offset+(streamoff)buffer[current_buffer].length()))
break;
return -1;
}
}
setg(eback(), eback() + (streamoff)(sp - begin_offset), egptr());
return sp;
}
int streambuf::sputbackc(char c)
{
if (_gptr > _eback && (unsigned char)_gptr[-1] == (unsigned char)c) {
_gptr--;
return (unsigned char)c;
}
return pbackfail(c);
}
int streambuf::sungetc()
{
if (_gptr > _eback) {
_gptr--;
return (unsigned char)*_gptr;
}
else
return pbackfail(EOF);
}
// Unput one character.
int_type sunputc()
{
if( (!pptr()) || (pptr() == pbase()) )
return pbackfail();
pbump(-1);
// This is safe because *epptr() always is '\0' and inside
// the backing buffer.
return traits_type::to_int_type(*(pptr()+1));
}
int
streambuf::sputbackc(char c)
{
#if defined(OS_INCLUDE_STREAMBUF_BUFFERS)
if (mgbeg == 0 || mgnext == mgbeg || !traits::eq(c, gptr()[-1]))
{
return pbackfail(traits::to_int(c));
}
gbump(-1);
return traits::to_int(*gptr());
#else
c = c;
return traits::eof();
#endif
}
/**
Move get pointer backwards and return bit at new position.
\param[out] value Bit before position prior to call.
\return Whether okay (eof has not been encountered).
*/
bool sungetb(bitfield &b)
{
bool unget_succeeded;
if (gptr() == std::streampos(-1) || gptr() == eback())
{
bitfield dummy;
unget_succeeded = pbackfail(dummy);
}
else
{
gbump(-1);
unget_succeeded = atgptrb(b);
}
return unget_succeeded;
}
/**
Put bit at get pointer.
\param[out] b Bit to be put back.
\return Whether okay (eof has not been encountered).
*/
bool sputbackb(bitfield b)
{
bool putback_succeeded;
if (gptr() == std::streampos(-1) || gptr() == eback() ||
b != atgptrb(-1))
{
putback_succeeded = pbackfail(b);
}
else
{
gbump(-1);
putback_succeeded = gptr() != std::streampos(-1);
}
return putback_succeeded;
}
