[Issue 15542] pure function with no argument returning different values (with void-initialized static array)

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=15542

Steven Schveighoffer <schveiguy at yahoo.com> changed:

           What    |Removed                     |Added
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             Status|NEW                         |RESOLVED
                 CC|                            |schveiguy at yahoo.com
         Resolution|---                         |INVALID

--- Comment #6 from Steven Schveighoffer <schveiguy at yahoo.com> ---
(In reply to Jonathan M Davis from comment #5)
> (In reply to ag0aep6g from comment #4)
> > Note that the test code still compiles even when you add `@safe`. Void
> > initialization of value types is considered `@safe`.
> 
> Hmmm. I'm inclined to think that that's a bug, but I suppose that it depends
> on what types it lets you void initialize. I guess that if it's just ints
> and floats and whatnot in the struct, then that doesn't actually pose a
> memory safety problem and wouldn't need to be marked @system, but it still
> seems wrong.

That particular case is not a bug. It's perfectly memory safe to look at/use
your own stack frame without initialization, as long as data doesn't contain a
reference.

> Either way, I think that it's pretty clear that you're dealing with
> undefined behavior if you use a void-initialized object before giving it a
> proper value, and I don't see any reason to treat pure as special in that
> regard.

Agree. This is not a bug, just bad code.

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