What are the prominent downsides of the D programming language?

[mw]

On Monday, 21 September 2020 at 10:42:55 UTC, Walter Bright wrote:
> On 9/21/2020 2:35 AM, Ruby The Roobster wrote:
>> One downside is that classes can't inherit from multiple 
>> classes.
>
> That's a feature, not a downside. I'm not joking.

As you admitted some time earlier, the other mechanisms such as 
sub-typing, mixin has effectively introduced multiple inheritance 
into D already.

> Multiple inheritance is a horrible abstraction, all it does is 
> confuse people.

Well, if it's designed or implemented poorly in the language.


https://forum.dlang.org/post/iajvjzaskzwlhcuztiiz@forum.dlang.org

I think this deserved to be more widely known:

The diamond problem is a *solved* problem by Eiffel language, 
which won the 2006 ACM Software System Award:

https://en.wikipedia.org/wiki/ACM_Software_System_Award

And I showed the concrete example here:

https://forum.dlang.org/thread/obqthozmxwzhvrafothw@forum.dlang.org