Reference
C Library
IOstream Library
Strings library
STL Containers
STL Algorithms
Miscellaneous
IOstream Library
manipulators
classes:
filebuf
fstream
ifstream
ios
iostream
ios_base
istream
istringstream
ofstream
ostream
ostringstream
streambuf
stringbuf
stringstream
objects:
cerr
cin
clog
cout
types:
fpos
streamoff
streampos
streamsize
streambuf
streambuf::streambuf
streambuf::~streambuf
public members:
streambuf::getloc
streambuf::in_avail
streambuf::pubimbue
streambuf::pubseekoff
streambuf::pubseekpos
streambuf::pubsetbuf
streambuf::pubsync
streambuf::sbumpc
streambuf::sgetc
streambuf::sgetn
streambuf::snextc
streambuf::sputbackc
streambuf::sputc
streambuf::sputn
streambuf::sungetc
protected members:
streambuf::eback
streambuf::egptr
streambuf::epptr
streambuf::gbump
streambuf::gptr
streambuf::pbase
streambuf::pbump
streambuf::pptr
streambuf::setg
streambuf::setp
virtual prot. members:
streambuf::imbue
streambuf::overflow
streambuf::pbackfail
streambuf::seekoff
streambuf::seekpos
streambuf::setbuf
streambuf::showmanyc
streambuf::sync
streambuf::uflow
streambuf::underflow
streambuf::xsgetn
streambuf::xsputn


streambuf::seekpos

virtual protected member function
streampos seekpos ( streampos sp, ios_base::openmode which = ios_base::in | ios_base::out );

Set internal position pointer to absolute position

This member is called to set a new value for the position pointer in streambuf-derived objects. The public member function pubseekpos 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 the absolute position sp.

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::seekpos and stringbuf::seekpos).

Parameters

sp
New absolute position for the position pointer.
This is an object of class streampos (or traits::pos_type for other traits). streampos objects may be constructed from streamoff directly from integral values representing a relative position from the beginning of the stream.
which
Determines which of the internal position pointers shall be modified: the input pointer, the output pointer, 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:
valueposition pointer affected
ios_base::ininput position pointer
ios_base::outoutput position pointer

Return Value

The new position value of the modified position pointer.
In case of error, the value returned shall be an invalid position, like -1.

Basic template member declaration

( basic_streambuf<charT,traits> )
1
2
 
typedef traits::pos_type pos_type;
pos_type seekpos (pos_type sp, ios_base which = ios_base::in | ios_base::out );


See also

streambuf::pubseekpos Set internal position pointer to absolute position (public member function)
streambuf::seekoff Set internal position pointer to relative position (virtual protected member function)