Struct should be invalid after move

[John Colvin]

On Wednesday, 28 November 2018 at 09:30:21 UTC, Sebastiaan Koppe 
wrote:
> On Wednesday, 28 November 2018 at 09:11:48 UTC, Stefan Koch 
> wrote:
>> So ... what you want is this:
>>
>> "Compiler, ensure that there is no possible execution-flow 
>> path in which this variable is ever set to 0."
>
> Almost. I want to prevent usage *after* it is set to 0. Similar 
> to how the compiler already recognises this error:
>
> ---
> void main() {
>   int* p = null;
>   (*p) = 5;  // <- Error: null dereference in function _Dmain
> }
> ---
>
> Which more and more languages already provide. Swift, Kotlin 
> etc.

Sure, catching some simple cases is definitely doable, if someone 
has the compiler chops (or is prepared to learn) and some time to 
dedicate to it.

I suspect if it was a small code change and had a zero 
false-positive rate (I.e. only caught things that *definitely* 
were wrong) then it would be accepted. Large code change -> 
uncertain. Any false positives that forbid valid programs -> 
unlikely to be accepted.

That's just my feeling though, who knows....