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Some bits on malloc(0) in C being allowed to return NULL

(utcc.utoronto.ca)
48 points ingve | 1 comments | 25 Jun 25 06:15 UTC | HN request time: 0.258s | source
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Lvl999Noob ◴[26 Jun 25 18:50 UTC] No.44390177[source]▶
Can 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.

replies(2): >>44390264 #>>44392169 #
1. hansvm ◴[26 Jun 25 18:59 UTC] No.44390264[source]▶
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.