Contracts, Undefined Behavior, and Defensive,Programming

[Dukc]

On Saturday, 13 June 2020 at 08:52:18 UTC, Johannes Pfau wrote:
> [snip]

A very good point, has not occured to me before. But I think I 
can give a more specific example of what you're trying to convey:

```
@safe auto readIndex(int[] arr, size_t i)
in (i < arr.length)
{	return arr[i];
}
```

Because the compiler is free to assume that the contract holds, 
it can elide the array bounds check. If it does that, it results 
in memory violation from `@safe` code.

This is something that should only be possible if 
`-boundscheck=off`. Not otherwise.