...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Returns true
if the latest
message data indicates binary.
bool got_binary() const;
This function informs the caller of whether the last received message frame represents a message with the binary opcode. If there is no last message frame, the return value is undefined.