DIP71: 'noscope' and 'out!param' attributes

[Meta via Digitalmars-d]

On Sunday, 18 January 2015 at 18:12:57 UTC, Zach the Mystic wrote:
> http://wiki.dlang.org/DIP71
>
> I want to keep this simple. There are three ways for a 
> reference passed to a function to escape that function.
>
> static T* s;
>
> T* fun(T* p1, T** p2) {
>   // escape by global
>   s = p1;
>
>   // escape by return
>   return p1;
>
>   // escape by mutable argument
>   *p2 = p1;
> }
>
> Because escape by return is by far the most common, adding 
> 'return' parameters as in DIP25 clearly makes a lot of sense. 
> It just bugs me that the other two types of escape are still 
> possible. I think they shouldn't be. DIP71 introduces two new 
> attributes, "out!param" and "noscope" to address this.
>
> I have a lot of other thoughts about this issue, but I want to 
> save them for a different thread.

If your function is marked as pure, then escape by global is 
impossible.