strstreambuf::seekpos

A protected virtual member function that tries to alter the current positions for the controlled streams.

virtual streampos seekpos(
   streampos _Sp,
   ios_base::openmode _Which = ios_base::in | ios_base::out
);

Parameters

  • _Sp
    The position to seek for.

  • _Which
    Specifies the mode for the pointer position. The default is to allow you to modify the read and write positions.

Return Value

If the function succeeds in altering either or both stream positions, it returns the resultant stream position. Otherwise, it fails and returns an invalid stream position. To determine if the stream position is invalid, compare the return value with pos_type(off_type(-1)).

Remarks

The protected virtual member function endeavors to alter the current positions for the controlled streams. For an object of class strstreambuf, a stream position consists purely of a stream offset. Offset zero designates the first element of the controlled sequence. The new position is determined by _Sp.

If _Which & ios_base::in is nonzero and the input buffer exists, the function alters the next position to read in the input buffer. If _Which & ios_base::out is nonzero and the output buffer exists, the function also sets the next position to write to match the next position to read. Otherwise, if _Which & ios_base::out is nonzero and the output buffer exists, the function alters the next position to write in the output buffer. Otherwise, the positioning operation fails. For a positioning operation to succeed, the resulting stream position must lie within the controlled sequence.

Requirements

Header: <strstream>

Namespace: std

See Also

Reference

strstreambuf Class

iostream Programming

iostreams Conventions

Other Resources

strstreambuf Members