[tcbawo]

I agree that it's consistent, I find it easier to read when the branching condition is front and center. In 99% of cases I've encountered, the scope of the branching condition variable doesn't matter. When it does, an extra set of {} defines a scope clearly.

[leni536]

An extra set of {} seems to be clutter to me.

[lomnakkus]

That plus extra indentation. It also obscures the intent since it's not necessarily unambiguous why those braces are there? Is it just to group logically related code (without putting it in a separate method/function) or is it because you're relying on RAII -- it's only possible to tell by searching for destructors on all the classes you're instantiating.