• d-bugmail puremagic.com (42/42) Jan 14 2023 https://issues.dlang.org/show_bug.cgi?id=23628

d-bugmail puremagic.com writes:

https://issues.dlang.org/show_bug.cgi?id=23628

          Issue ID: 23628
           Summary: ` safe` prohibits capture if lazy delegate
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Keywords: rejects-valid
          Severity: normal
          Priority: P3
         Component: dmd
          Assignee: nobody puremagic.com
          Reporter: destructionator gmail.com
        Depends on: 23627

```

struct W {
        string delegate() magic;
         safe
        void content(lazy string s) {
                magic = &s;
        }
        string test;
}

void main() {
        W w;

        w.content = w.test;
}

```

lzy.d(5): Error: cannot take address of lazy parameter `s` in ` safe` function
`content`



The spec explicitly permits the taking of this address and since it is lowered
to a delegate, the same rules should apply.

I suspect this was added as a hack because the implementation incorrectly fails
to generate a closure for lazy params:
https://issues.dlang.org/show_bug.cgi?id=23627

But the spec says nothing of the sort. If I wanted a `scope lazy`, I would have
written `scope lazy`.


Referenced Issues:

https://issues.dlang.org/show_bug.cgi?id=23627
[Issue 23627] lazy params don't allocateclosures
--