Even in C, setjmp/longjmp leave all non-volatile automatic storage duration variables on the current stack frame in an indeterminate state if they are modified

Even in C, setjmp/longjmp leave all non-volatile automatic storage duration variables on the current stack frame in an indeterminate state if they are modified between the two calls. To get defined behaviour with regards to destructors, you simply have to make sure that the function calling setjmp doesn't internally use RAII. Call a wrapper function to do the setjmp and you're safe. Of course it's a whole other question whether using setjmp/longjmp to implement "exception handling in C" is a good idea in the first place.