DIP1000: Walter's proposal to resolve ambiguity of ref-return-scope parameters

[zjh]

On Friday, 26 November 2021 at 02:17:18 UTC, zjh wrote:

`Return ref` replace with `@`,and `return scope` replace with `%`
Why not?
```d
struct S {
     ref int opIndex() return ref scope {
     }
}
//VS
struct S {
     int&opIndex()@%{

     }
}
```