Read up to the specified numBytes characters from this object to the specified buffer and return the number of characters successfully read. A return value of 0 means that either a UTF-8 error or end of file has been encountered (errorStatus must be called to distinguish between the two), but a non-zero return value less than numBytes will usually be returned when neither end of file nor a UTF-8 error has been encountered. The behavior is undefined unless 4 <= numBytes. Note that this function is forwarded to by the public method sgetn in the base class.
Declared in <bdlde_utf8checkinginstreambufwrapper.h>
virtual
std::streamsize
xsgetn(
char* buffer,
std::streamsize numBytes) override;