On 07/09/2017 07:34 PM, Meta wrote:
On Sunday, 9 July 2017 at 22:28:50 UTC, Andrei Alexandrescu wrote:
On 07/09/2017 03:12 PM, Walter Bright wrote:
On 7/9/2017 6:13 AM, Andrei Alexandrescu wrote:
We should use typeof(assert(0)) for Bottom. There is precedent -
there is no name for typeof(null).
I had forgotten about the typeof(null) thing. You're right. But there
are some issues. What do we do with:
typeof(assert(0))* p;
? What does that mean?
That would be a pointer that may only be null - a consequence of the
typeof(assert(0)) being uninstantiable.
Generally I'm not too worried about constructs like
typeof(assert(0))[], typeof(assert(0))*, use in templates etc - we
don't need to "design" these cases, their behavior flows from the
properties of typeof(assert(0)) itself.
Similarly, I don't recall ever there being a problem with
typeof(null)*, typeof(null)[], people complaining they passed
typeof(null) to a template where it did bad things, etc.
Andrei
`typeof(null)` actually has one valid value and doesn't crash the
program when when you try to create an instance of it. We should not
treat this the same as `typeof(null)`.
Agreed (with the mention it's not in contradiction with the above). --
Andrei
