Needless pointer-casts in C

Question

I got a comment to my answer on this thread:

Malloc inside a function call appears to be getting freed on return?

In short I had code like this:

Answer 1

One possible error it can introduce is if you are compiling on a 64-bit system using C (not C++).

Basically, if you forget to include stdlib.h, the default int rule will apply. Thus the compiler will happily assume that malloc has the prototype of int malloc(); On Many 64-bit systems an int is 32-bits and a pointer is 64-bits.

Uh oh, the value gets truncated and you only get the lower 32-bits of the pointer! Now if you cast the return value of malloc, this error is hidden by the cast. But if you don't you will get an error (something to the nature of "cannot convert int to T *").

This does not apply to C++ of course for 2 reasons. Firstly, it has no default int rule, secondly it requires the cast.

All in all though, you should just new in c++ code anyway :-P.