Thread: I have a Question about memory usage for C.

To oomakoo I gave up trying to explain because I felt like a broken record and didn't want to plague people with a spam war.

What have you explained? The only place I could find any sort of explaination was (I assume you were unregistered) -

In addition, omitting the cast does, as Quzah said, allow the compiler to be more accurate in what errors/warnings it provides you.

Exactly what errors/warnings is the compiler going to give (with no cast) when assigning from a void pointer? The only way to enable the compiler to do any sort of checking would be to cast.

Leave out the needed header, and your program will compile without error if you've typecast everything.

Quzah.

I get the same warning messages with or without the cast (implicit declaration).

I get the same warning messages with or without the cast (implicit declaration).

Hm... You may be right. I'm not at a compiler now. Shrug. Oh well. I can't recall the error, or how to do it, (maybe it's just a warning?) but I know there's one you can get with casts. I've done it in the past--i think. It's been a long time. I generally never cast malloc except on accident. Just the way I do it.

Quzah.

Testing on a few different compilers produces different results, so this may be the warning you are thinking of. However, the only compliant C99 compiler that I know of gives errors if stdlib.h isn't included regardless of whether you cast or not. I suppose it's up to the compiler writers what warnings to include on a pre-C99 compiler.

You could argue that assigning the result of malloc to a pointer that you thought was of a different type could result in a harder to find bug than forgetting to include stdlib.h. If you're careful though, neither would be a problem.