protected member function
Increase put pointer
Adds n to the put pointer.
The put pointer (pptr) is the internal pointer that points to the current location in the array with the buffered portion of the controlled output sequence.
- Value by which to increase the put pointer.
This shall be a value such that
pptr()+n is in the range between pbase and epptr.
Modifies the stream buffer object.
Concurrent access to the same stream buffer object may cause data races.
Basic guarantee: if an exception is thrown, the stream buffer is in a valid state.
Invalid arguments cause undefined behavior.