Feedback on Átila's Vision for D

[John Colvin]

On Wednesday, 16 October 2019 at 11:08:18 UTC, Atila Neves wrote:
> On Wednesday, 16 October 2019 at 07:09:38 UTC, JN wrote:
>> On Tuesday, 15 October 2019 at 16:17:57 UTC, Atila Neves wrote:
>>>
>>> Meh:
>>>
>>> //C++20 concepts
>>> concept isAddable = requires (T x) { x + x; };
>>>
>>> // D
>>> enum isAddable(T) = is(typeof((T x) => x + x));
>>>
>>>
>>> We lose by one character ;)
>>
>> I disagree. It's not just one character. C++ example is much 
>> cleaner. Imagine not being experienced with C++ and D and 
>> seeing these two examples.
>
> Ok:
>
> enum requires(alias F) = is(typeof(F));
> enum isAddable(T) = requires!((T x) => x + x);
> static assert(isAddable!int);

static assert(!isAddable!string); doesn't work so nicely