• HuskyNator (14/14) Jan 06 2022 I can't figure out why this code works:
• Paul Backus (6/20) Jan 06 2022 This is a known bug in the compiler's inference of the `@safe`

HuskyNator <HuskyNator protonmail.ch> writes:

I can't figure out why this code works:
```d
union A {
	int* b;
	float c;
}

int fun(A a)  safe {
	return *(()=>a.b)();
	// return *a.b; //Complains about pointer type overlap
}
```

I tried to find out how ` safe` should be handled in this 
scenario, and found [lambda's could be denoted as 
 trusted](https://dlang.org/blog/2016/09/28/how-to-write-trusted-code-in-d/#:~:text=is%20used%20instead.-,%40trusted%20escapes,-A%20%
0trusted%20escape), but this even works without a ` trusted` denotation. Am I
missing something?

Paul Backus <snarwin gmail.com> writes:

On Thursday, 6 January 2022 at 16:12:10 UTC, HuskyNator wrote:
 I can't figure out why this code works:
 ```d
 union A {
 	int* b;
 	float c;
 }

 int fun(A a)  safe {
 	return *(()=>a.b)();
 	// return *a.b; //Complains about pointer type overlap
 }
 ```

 I tried to find out how ` safe` should be handled in this 
 scenario, and found [lambda's could be denoted as 
  trusted](https://dlang.org/blog/2016/09/28/how-to-write-trusted-code-in-d/#:~:text=is%20used%20instead.-,%40trusted%20escapes,-A%20%
0trusted%20escape), but this even works without a ` trusted` denotation. Am I
missing something?

This is a known bug in the compiler's inference of the ` safe` 
attribute.

* Bug report: https://issues.dlang.org/show_bug.cgi?id=20655
* Fix PR: https://github.com/dlang/dmd/pull/10884

Looks like the fix is currently blocked due to other issues.