Re: (no subject)

> - What is the variable atomic in the parameters of Data()=3F

IIRC when atomic == true Data() is expected to contain a single
and complete MIDI message. With atomic == false you could in
theory send a MIDI message in segments perhaps (for a large
sysex dump), but in practice I think the message callback will
not be called for messages sent with atomic == false.

> - And what is the Key Word "mutable" before BLocker=3F none of the book I
> have about C++ talk about.

If a member is declared mutable it can be changed by a member
function declared const.

I recommend "The C++ programming language" by Stroustrup.

--martijn