assume, assert, enforce, @safe

[via Digitalmars-d]

On Thursday, 31 July 2014 at 10:24:07 UTC, ponce wrote:
> If I write:
>
> ---
> switch(expr())
> {
> case 0: doIt();
> case 1: doThat();
> default:
>   assert(0);
> }
> ---
>
> Will the optimizer be able to remove the default: case?

Assuming fall-through (`goto case`), not only the default case. 
The entire switch could be removed, under the condition that the 
compiler can prove that neither `expr()`, `doIt()`, nor 
`doThat()` throws, even if they have side effects. And maybe even 
the entire function, and all functions that call it, depending on 
how exactly the control flow is.