First: Lose the cast. It's not needed in C, clutters the code, and can hide real problems (like implicit declarations of the functions -- this can cause crashes

First: Lose the cast. It's not needed in C, clutters the code, and can hide real problems (like implicit declarations of the functions -- this can cause crashes on 64-bit architectures). A void* exists solely so it can be assigned to any type* without casts. It's useless for any other purpose. Yes, they are effectively the same. I'd suspect that on most systems (glibc, certainly) calloc more or less does: mem = malloc(nelem * size); memset(mem, 0, nelem * size); return mem;