streampos seekoff ( streamoff off, ios_base::seekdir way, ios_base::openmode which = ios_base::in | ios_base::out );

Set internal position pointer to relative position

This member is called to set a new value for the position pointer in streambuf-derived objects. The public member function pubseekoff calls this protected member function to perform this action.

This is a virtual member function that shall be redefined in derived classes to behave as expected by setting the internal pointer specified by which to a position offset off characters relative to the direction way.

Its default behavior in streambuf is to do nothing and return the invalid position -1, but it is redefined in both standard derived classes, filebuf and stringbuf, to behave as expected specifically for each type of buffer (see filebuf::seekoff and stringbuf::seekoff).

Parameters

off

Offset value. This is relative to the way parameter.
It is a value of type streamoff.

way

Object of type ios_base::seekdir. It may take any of the following constant values:

value	offset is relative to...
ios_base::beg	beginning of the stream buffer
ios_base::cur	current position in the stream buffer
ios_base::cur	end of the stream buffer

which

Determines which of the internal position pointers shall be modified, either the get pointer (input), the put pointer (output) or both. It is an object of type ios_base::openmode, that may take any combination of the following significant constant values:

value	position pointer affected
ios_base::in	Modify get pointer position
ios_base::out	Modify put pointer position

Return Value

Basic template member declaration

typedef traits::pos_type pos_type;
typedef traits::off_type off_type;
pos_type seekoff (off_type off, ios_base::seekdir way, ios_base which = ios_base::in | ios_base::out );

See also