BloombergLP::bslx::GenericOutStream::putLength

If the specified length is less than 128, write to the stream supplied at construction the one‐byte integer comprised of the least‐significant one byte of the length; otherwise, write to the stream the four‐byte, two's complement integer (in network byte order) comprised of the least‐significant four bytes of the length (in host byte order) with the most‐significant bit set. Return a reference to this stream. If this stream is initially invalid, this operation has no effect. The behavior is undefined unless 0 <= length.