protected virtual member function
<streambuf> <iostream>
pos_type seekpos (pos_type pos, ios_base::openmode which = ios_base::in | ios_base::out);
Set internal position pointer to absolute position
Virtual function called by the public member function pubseekpos to alter the stream positions of one or more of the controlled sequences in a specific way for each derived class.
Its default behavior in basic_streambuf is to do nothing and return -1, but derived classes shall override this behavior to alter the internal pointers appropriately: both basic_filebuf and basic_stringbuf override this virtual member function to set the internal pointer specified by which to the absolute position pos.
Parameters
- pos
- New absolute position for the position pointer.
Member type pos_type is determined by the character traits: generally, it is an fpos type (such as streampos) that can be converted to/from integral types.
- which
- Generally used to determine the position on which of the controlled sequences shall be modified: the input sequence, the output sequence, or both. It is an object of type ios_base::openmode that, for this function, may take any combination of the following significant constant values:
| value | position pointer affected |
|---|
| ios_base::in | Modify current position in controlled input sequence |
| ios_base::out | Modify current position in controlled output sequence |
Return Value
Returns pos_type(off_type(-1)).
Member type pos_type is determined by the character traits: generally, it is an fpos type (such as streampos) that can be converted to/from integral types.
Data races
Introduces no data races, but overriden versions in derived classes may.
Exception safety
No-throw guarantee: this default definition never throws exceptions.