Type safety could prevent nuclear war

[tsbockman via Digitalmars-d]

On Friday, 5 February 2016 at 00:12:07 UTC, Ola Fosheim Grøstad 
wrote:
> It makes perfect sense for one compilation unit to type a 
> parameter pointer to float  and another unit to type the same 
> parameter as a simd-array of floats. The underlying code could 
> be machine language. And in machine language there are no types 
> (on current CPUs), only bit patterns. So you can have multiple 
> reasonable interpretations of the same machine language entry.
>
> A type is a constraint, but it isn't a property of the actual 
> bits, it is a language specific interpretation.

Aliasing types like that can be useful sometimes, but only within 
certain limits. In particular, the size (with alignment padding) 
of the types in question must match, otherwise you will corrupt 
the stack.

It is often useful to cast from one pointer type to another, but 
that is why C has void* and explicit casts - so that one may 
document that the reinterpretation is intentional.