I didn't know the part where the standard lets you malloc a buffer, write it as int, read it as int, then write it as float, and read it as float, all without freeing, and how the compiler thus has to treat heap memory differently from other memory. The part where compilers are too aggressive to follow this rule actually makes sense (as it seems to greatly increase the chance of valid optimizations based on type-based alias analysis to actually happen; it's hard to prove that a given pointer wasn't malloced.)

I wonder if the story is different with C++'s operator new, which returns a typed result.