DIP 1021--Argument Ownership and Function Calls--Community Review Round 1

[Paul Backus]

On Monday, 15 July 2019 at 15:23:32 UTC, Mike Parker wrote:
> This is the feedback thread for the first round of Community 
> Review for DIP 1021, "Argument Ownership and Function Calls":
>
> https://github.com/dlang/DIPs/blob/793f83911fdc8c88c6ef34e6a36b5e11e3e574e5/DIPs/DIP1021.md

Do these new checks also handle the case where one of the 
references is passed implicitly to a delegate or nested function 
via their context? In other words, if we re-write the example 
from the DIP to use a nested function, like so:

struct S {
     byte* ptr;
     ref byte get() { return *ptr; }
}

void test() {
     S s;
     s.ptr = cast(byte*) malloc(1);

     void foo(ref byte b) {
         free(s.ptr);
         b = 4;
     }

     foo(s.ptr);
}

Will the call to `foo` here be correctly flagged as taking 
multiple mutable references to `s`?