filebuf::overflow

int overflow ( int c = EOF );

Attempts to write c to the current position of the put pointer pptr, and advances that pointer one position forward.

Before proceeding, the function may reallocate and modify the internal output array (defined by pbase, pptr and epptr) to make more write positions available. Therefore the function may be successful even if the put pointer was at the end of the internal output array.

If c is EOF (or traits::eof() for other traits) no character is written and the put pointer is not advanced, but the function may still modify the internal output array to make more write positions available.

Parameters

c

Character to be written, or EOF (or traits::eof() if no character is to written).

Return Value

A value different than EOF (or traits::eof() for other traits) signals success.
If the function fails, EOF (or traits::eof() for other traits) is returned.

Basic template member declaration

( basic_filebuf<charT,traits> )