Move characters from the output sequence to the input sequence.
void commit( std::size_t n);
Appends n
characters from the start of the output sequence
to the input sequence. The beginning of the output sequence is advanced
by n
characters.
Requires a preceding call prepare(x)
where x >= n
,
and no intervening operations that modify the input or output sequence.
If n
is greater than the size of the output sequence, the
entire output sequence is moved to the input sequence and no error is issued.