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by tom_ 2804 days ago
Realloc's behaviour is well-defined: https://port70.net/~nsz/c/c11/n1570.html#7.22.3.5p3

If the size of the space requested is zero, the behavior is implementation-defined: https://port70.net/~nsz/c/c11/n1570.html#7.22.3
1 comments
richardwhiuk 2804 days ago
Being implementation defined is hardly well defined.
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apankrat 2804 days ago
Well, it's the return value in realloc(ptr, 0) case that is implementation-specific, but its behavior _is_ well-defined - it is expected to "deallocate the old object".

My point was that in reality the behavior varies. "Undefined" in a common tongue sense, not in the terms of the C standard.

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tom_ 2804 days ago
No... maybe? It's probably arguable, even if it's not an interesting argument.

Either way, realloc's behaviour is well-defined when the pointer is null.

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