RFC: scope and borrowing

[via Digitalmars-d]

On Monday, 25 August 2014 at 10:27:53 UTC, Kagamin wrote:
> Can't scope(int*) on return type be equivalent to 
> scope!(a,b)(int*)? How often this is not desired?

You mean as a default?

It would be desired in `chooseStringAtRandom`, but not in the 
`findSubstring`, whose returned string shouldn't be limited by 
the scope of the needle. If it is made the default, there would 
need to be a way to opt out, such as removing an owner.

But note that in the `chooseStringAtRandom` example, it would be 
sufficient to declare it as:

     scope chooseStringAtRandom(scope(string) a, scope(string) b) {
         return random() % 2 == 0 ? a : b;
     }

Type deduction would then automatically add `a` and `b` as the 
owners, by the rules under "Owner tracking".