cpp/io/basic filebuf/overflow

Writes some data from the put area to the associated character sequence (to the file).

Behaves like the base class std, except that to write the data, first uses std of the imbued locale to convert the characters into external (possibly multibyte) representation, stored in a temporary buffer (allocated as large as necessary), then uses file I/O to copy all fully-converted bytes into the file.

If std is true, the call to std may be skipped.

If the conversion fails with std, returns without attempting any output.

If the associated file is not open, returns before doing anything.

Parameters
(none)

Return value
to indicate success or to indicate failure.