This might be a stupid question, but what are you meant to do if not cast malloc's return?
My C is a bit rusty, but how else are you meant to allocate data of different types on the heap?
My C is a bit rusty, but how else are you meant to allocate data of different types on the heap?
First, as someone else already pointed out, it can lead to an LP64 bug if you miss the declaration for malloc(), since int and caddr_t are not necessarily the same thing.
But the bigger problem is that casting to void* basically tells the compiler "stop all further type checking". That's not a big deal if the token "malloc" on that line never changes, but, in real codebases, allocators get changed all the time. If you change from foo_alloc() to bar_alloc(), the compiler will rightly freak out when you try to assign a foo* to a bar. But that (void) construction explicitly prevents that check from occurring, thus turning what should be a compile-time error into a runtime error.
C++, however, does not allow this. So, if for some reason you're calling malloc rather than new in C++, you need to cast.