C++ pattern matching is coming

[ryuukk_]

On Monday, 24 October 2022 at 14:39:26 UTC, bachmeier wrote:
> On Monday, 24 October 2022 at 14:05:47 UTC, Quirin Schroll 
> wrote:
>
>>> A more modern one would be:
>>>
>>>     match (x)
>>>     {
>>>         0 => foo();
>>>         3 => bar();
>>>     }
>>>
>>> Note the lack of need for `break`.
>>
>> No. Java re-used the `swtich` keyword and IMO is correct in 
>> doing so. The rest is great as in Java.
>
> IMO `match` is a much better name than `switch`, which I didn't 
> find intuitive when I first encountered it, and it only made 
> sense because it was followed by a series of `case` statements. 
> I would like the above syntax plus
>
> ```
> match (x)
> {
>       0 => &foo;
>       3 => &bar;
> }
> ```
>
> where `foo` and `bar` are functions taking one argument, and
>
> ```
> match (x)
> {
>       case(0):
>          lines of code
>          break;
>       3 => &foo;
>       4 => bar();
> }
> ```
>
> No idea if this would be possible/sensible, but it's one of the 
> few things that would be a big improvement when I'm writing D 
> programs.


What about:

```D
auto result = switch (x)
{
    0,1,2 => aaa();
    3 => bbb();
    4 => ccc();
    5 => {
         int a = 1+1;
         return a;
    };
    else => 0;
}
```


If the symbol after switch is not "``case``" or "``default``", 
then the compiler can process it as "enhanced" switch