It's rare that there is no chance of exceptions being thrown anywhere in a function, especially in the futurer as the code changes.. But even if you're really sure, it's so idiomatic to do cleanup in a destructor in C++ that it looks wrong to leave some cleanup code at the end of a function. Plus, it means you can think about cleanup at the same time you're thinking about creation, then forget about it later; one less thing to think about during the lifetime of the function.
I think life is simpler if you just adopt a blanket rule: all cleanup is done in destructors/scoped guards. Occasionally code might be slightly longer than it needs to be, but your life is simpler overall. Plus you can forget the old C rule of only one return from a function that you mentioned. (If you use exceptions anywhere then you already stopped using that rule anyway.)
I think life is simpler if you just adopt a blanket rule: all cleanup is done in destructors/scoped guards. Occasionally code might be slightly longer than it needs to be, but your life is simpler overall. Plus you can forget the old C rule of only one return from a function that you mentioned. (If you use exceptions anywhere then you already stopped using that rule anyway.)