Associative Arrays with elements having function type?

[Nicholas Wilson]

On Tuesday, 11 November 2025 at 17:58:33 UTC, Quirin Schroll 
wrote:
> On Monday, 3 November 2025 at 22:29:13 UTC, H. S. Teoh wrote:
>> On Mon, Nov 03, 2025 at 09:29:47PM +0000, kdevel via 
>> Digitalmars-d wrote:
>>> Yesterday I read
>>> 
>>>     3. Neither the KeyTypes nor the element types of an 
>>> associative array
>>>     can be function types or void.
>>> 
>>> in <https://dlang.org/spec/hash-map.html>. Does the program 
>>> below work only accidentally?
>> [...]
>>
>> I think this is a mistake in the spec. There is no reason why 
>> the value type of an AA can't be a function (pointer) or 
>> delegate.  I use this quite a lot.
>
> There’s a big difference between a function type and a function 
> pointer type. (I don’t know why D even has function types. 
> Borderline useless.)

For internal compiler organisation reasons, for mangling, and for 
C++ interoperability.
Very useful, just indirectly.