What are the unused but useful feature you know in D?

[Atila Neves]

On Sunday, 5 November 2017 at 03:02:52 UTC, rikki cattermole 
wrote:
> On 04/11/2017 6:13 PM, bauss wrote:
>> On Saturday, 4 November 2017 at 13:27:29 UTC, rikki cattermole 
>> wrote:
>>> [...]
>> 
>> It reminds a lot of traits in Rust.
>> 
>> https://doc.rust-lang.org/1.8.0/book/traits.html
>
> Rust traits are a variant of ML's signature. Only they decided 
> to add a whole new concept which is 'impl' to it.
>
> While it is a nice idea, it would be a pain to use in real life 
> and defeat the purpose of a signature. Which is to act as more 
> of a 'concept' abstraction to other items.
>
> Because we have such powerful meta-programming features I see 
> no reason to separate out the two. We can do it all in one 
> which makes it nice and consistent between all the different 
> implementations for a signature type. So far its starting to 
> feel right at home against our structs and class support, I 
> think.

I like Rust's traits more than our way of ad-hoc specification of 
compile-time interfaces with is(typeof({...})) or 
__traits(compiles, ...). Given how most idiomatic D code is 
written, to me that's the biggest deficiency of the language. 
Reasonable people may, of course, disagree.

Atila