Pattern matching in C++ and D

[Francesco Mecca]

On Tuesday, 7 January 2020 at 17:06:30 UTC, IGotD- wrote:
> On Tuesday, 7 January 2020 at 14:00:01 UTC, Francesco Mecca 
> wrote:
>> I found a paper regarding a proposal for pattern matching in 
>> C++ on HN a few days ago:
>> http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1371r1.pdf
>>
>> ```
>> let function_with_side_effects x = ...
>> let match x = match x with
>>     | p1 -> e1
>>     | p2 when function_with_side_effects x -> e2
>>     | _ -> e3
>> ```
>
> Doesn't the real benefit first kick in when the statement is an 
> expression always returning a value like in your example?
>
> Neither C++ or D has that.

Yes, but that should be possibile in D, isn't it?