If required, throw a TestInStreamException (see throwExceptionIfInputLimitExhausted); otherwise, consume the 8-bit unsigned integer type code, verify the type of the next value in this stream, consume that 8-bit unsigned integer or 32-bit signed integer value representing a length (see the bslx package-level documentation) into the specified variable if its type is appropriate, update the cursor location, and return a reference to this stream. Consume an 8-bit unsigned integer if the most significant bit of this byte is 0, otherwise consume a 32-bit signed integer and set the most significant bit to zero in the resultant variable. If the type is incorrect, then this stream is marked invalid and the value of variable is unchanged. If this stream is initially invalid, this operation has no effect. If this function otherwise fails to extract a valid value, this stream is marked invalid and the value of variable is undefined.