C# switch pattern matching one default.

[Terry1511512]

I would like to see the pattern matching on a switch statement extended to the default case.
IE:
switch( SomeValue )
{
case Value1 when ( something == 0)
break;

case Value2 when ( something == 1)
break;

default when ( something == 1)
break;

default when ( something == 3)
break;

default:
break;
}

[RikkiGibson]

Consider using case var _ when (something == 1), for example.

I feel like there might be a simpler way to do this, such as case _ when ..., but it doesn't seem to be accepted.

[Terry1511512]

Only did it the long way for clarity.

[alrz]

case _ when ..., but it doesn't seem to be accepted.

IIRC that is by design. but I don't know why.

[PathogenDavid]

@alrz I could only find it mentioned in the LDM notes for 2017-11-29 and 2019-03-13. In both cases though the subject at hand is switch expressions rather than pattern matching as an alternative syntax to what we ended up with.

[Terry1511512]

To me it seems like a glaring hole in the switch statement if a "case" can have a "with" expression but a "default" cannot.

[CyrusNajmabadi]

I moved this to csharplang, as this is a discussion about a proposed change to the language.

[HaloFour]

Has this discussion been narrowed down to the desired syntax? Supporting a when clause with the default case, or supporting _ as a case? Or both? Technically case _ is already legal if _ is a constant in scope, although the compiler seems to warn in that case now.