Write up to the specified numBytes characters from the specified buffer and return the number of characters successfully written. Note that this method does not necessarily modify the file: this method may simply write the characters to a buffer to be flushed to the file at a later time. Also note that on a Windows text file, a ` ` will be written to the file as `\r ` (counted as a single character).
Declared in <bdls_fdstreambuf.h>
virtual
std::streamsize
xsputn(
char const* buffer,
std::streamsize numBytes) override;