DIP 1021--Argument Ownership and Function Calls--Formal Assessment

[Ola Fosheim Grøstad]

On Monday, 28 October 2019 at 21:53:50 UTC, Walter Bright wrote:
> I've always known it was a bad idea (not just me, it was common 
> knowledge). People have a hard time understanding restrict, and 
> are guaranteed to use it wrong. Let alone errors using it from 
> people who do understand it.
>
> Compiler enforcement is the only way to make it go.

It isn't possible to prove it for a compiler in many cases.  Not 
without full verification, and even then it is hard.

So yeah, having it is good, but requiring it isn't competitive 
(vs C restrict).