You mention C++, but surely these shenanigans (fascinating in their twistedness though they may be) belong entirely in the land of C?
In the first place, C++ entirely solves the problem of tidying away resources that go out of scope in a rather more thorough way. And, for that matter, iterators allow non-standard behaviours to be packaged in a for-loop-friendly way. (Even more friendly for C++11's range-based for loops.)
In the second, the combination of exceptions and C++'s somewhat necessary prohibition on jumping past a non-trivial constructor or destructor invocation make the idiom unusable in some cases and dangerous in others.
I mention C++ mostly because there exists at least one compiler which hasn't yet got round to supporting C99 – but that compiler does support C++. So if you're prepared to write code in the common subset of C99 and C++ (which mostly just means adding a few explicit casts from void *), then you can do this sort of thing even when one of the compilers you have to support is that one.
It's true, of course, that if you're writing a program that's actually allowed to use C++ features then you probably want to be doing an entirely different set of horrifying language abuses :-)
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In the first place, C++ entirely solves the problem of tidying away resources that go out of scope in a rather more thorough way. And, for that matter, iterators allow non-standard behaviours to be packaged in a for-loop-friendly way. (Even more friendly for C++11's range-based for loops.)
In the second, the combination of exceptions and C++'s somewhat necessary prohibition on jumping past a non-trivial constructor or destructor invocation make the idiom unusable in some cases and dangerous in others.
It's true, of course, that if you're writing a program that's actually allowed to use C++ features then you probably want to be doing an entirely different set of horrifying language abuses :-)