semi-final switch?

[Steven Schveighoffer]

On 6/18/21 6:35 AM, Johan wrote:
> On Thursday, 17 June 2021 at 21:41:28 UTC, Steven Schveighoffer wrote:
>>
>> However, sometimes the data I'm switching on is coming from elsewhere 
>> (i.e. a user), and while I want to enforce that the data is valid 
>> (it's one of the enum values), I don't want to crash the program if 
>> the incoming value is not correct. But final switch doesn't let me 
>> declare a default case (to throw an exception instead).
>>
>> If I use a non-final switch, then my code might forget to handle one 
>> of the cases.
>>
>> Any ideas on better ways to handle this?
> 
> Perhaps just a non-final switch, with a static assert comparing the 
> number of cases handled to the number of enum members? (managable if the 
> number of cases is small and easily countable)

Hm... interesting idea! I don't know how to count the number of cases, 
but possibly a CTFE validation would be possible (basically use CTFE to 
try all the switch cases, and if any throws an exception, then you found 
one that's not handled).

-Steve