alt Hacker NewsCan someone tell me a usecase where you want multiple allocations of size 0, each one with a unique address, and each one unique from any other allocation (hence necessarily removing that pointer from being allocated to anything else) but can't use malloc(1) instead?
I think it would be much better if malloc(0) just returned 1 or -1 or something constant. If the programmer needs the allocation to have a unique address, they can call malloc(1) instead.
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Because zero-size types exist which you might want to take the address of. Possibly as a result of macro substitution or templating mechanism that only appears in certain build configurations.
It means you don't need a bunch of special-case handling if one out of 27 types ends up with zero size in some situation. It just all works the same way. Especially the unique address part because that would be an annoying source of difficult to track bugs.
It's occasionally useful to want multiple allocations of size 0, each one with a valid address -- generic containers parsing something as a some sort of sequence object and you want all code interacting with it to do something valid. I'd be hard-pressed to see where you'd need those to be unique though. Basically any integer should be fine.