The C standard library `fflush` is used to synchronize the stream on which it is invoked with the actual content of the corresponding file. It can be used only on output streams. A similar function is defined in C++ as `std::fflush`.
The C standard library function fflush function is defined in the <stdio.h> header and its documentation can be found here.
The corresponding C++ standard library function std::fflush is defined in <cstdio> header and documented here.
