Are C ++ or 64-bit C object exceptions safely propagated through Swift code?

I know that C ++ exceptions and Swift exceptions (which are essentially syntactic sugar for NSError **) are completely different.

My question is that I can expect safe / normal behavior when the objective-c ++ code calls the Swift callback, which in turn calls the objective-c ++ code that throws the exception, and the original one throws the exception. Is this documented somewhere?

In my case, the writer of the Swift part will be aware of the situation, so please avoid suggestions on why this should be avoided from an architectural point of view. My question is more similar: Will Swift objects be emitted ARC- (auto), and will any other runlevel cleanup be done.