How to implement filterMap

[Alexandru Ermicioi]

On Friday, 29 December 2023 at 23:10:47 UTC, Christian Köstlin 
wrote:
> Is there a way to implement filterMap (meaning do mapping of a 
> range, but if something happens during the map, leave this 
> element out of the resulting range).

Perhaps try map to null cases that exception is thrown then 
filter out those, and then unwrap from nullable type:
```d
myRange.map!(e => e.to!T.asNullForException).filter!(e => 
!e.isNull).map!(e => e.get).myOtherAlgorithm()
```

where asNullForException will return empty `Nullable` in case 
conversion fails.