Nicer code for toggling a bool member

No. That's the optimal way. Congratulations!

Even IF there would be an other way (as you commented - _isIt!!), I believe that it would be better not to use it because you'd be raising a lot of eyebrows anyway.

In fact there is another option to toggle a boolean value, this will work:

_isIt ^= true;

However this is not better than the way you did...