In C, why do some people cast the pointer before freeing it?

Question

I'm working on an old code base and pretty much every invocation of free() uses a cast on its argument. For example, free((float *)velocity); free((float *)acceleration); free((char *)label);where each pointer is of the corresponding (and matching) type. I see no point in doing this at all. It's very old code, so I'm left wondering if it's a K&R thing. If so, I actually wish to support the old compilers that may have required this, so I don't want to remove them.Is there a technical reason to use these casts? I don't even see much of a pragmatic reason to use them. What's the point of reminding ourselves of the data type right before freeing it?EDIT: This question is *not* a duplicate of the other question. The other question is a special case of this question, which I think is obvious if the close voters would read all the answers.Colophon: I'm giving the "const answer" the checkmark because it is a bonafide real reason why this might need to be done; however, the answer about it being a pre-ANSI C custom (at least among some programmers) seems to be the reason it was used in my case. Lots of good points by many people here. Thank you for your contributions.

Answer 1

I've seen some of the older compilers complain when the pointer is not cast to void *

If it ain't broke, don't fix it