Pattern matching (switch expression) for Tuples (.Case)

[StefanBertels]

Does anybody know how pattern matchin can be done with tuples?

It worked using Case and SomeCase/ RightCase/LeftCase but this changed with https://github.com/louthy/language-ext/releases/tag/v3.5.24-beta

Not compiling (4.0.3):

[Fact]
void CaseTest()
{
    var set = Map((DateTimeOffset.MinValue, 42));

    Assert.True(set.FindExactOrSuccessor(DateTimeOffset.MinValue).Case is { Key: DateTimeOffset, Value: int } x1 && x1.Value == 42);
    Assert.True(set.FindExactOrSuccessor(DateTimeOffset.MinValue).Case is {} x2 && x2.Value == 42);
    Assert.True(set.FindExactOrSuccessor(DateTimeOffset.MinValue).Case is { Value: 42 });
    Assert.True(set.FindExactOrSuccessor(DateTimeOffset.MinValue).Case is (DateTimeOffset, int) x3 && x3.Value == 42 );
    Assert.True(set.FindExactOrSuccessor(DateTimeOffset.MinValue).Case is (var _, var _) x4 && x4.Value == 42 );
}

Workaround (for Option only, does not work for Either etc.):

[Fact]
void CaseTest()
{
    var set = Map((DateTimeOffset.MinValue, 42));

    Assert.True(set.FindExactOrSuccessor(DateTimeOffset.MinValue).ToNullable() is { Key: DateTimeOffset, Value: int } x1 && x1.Value == 42);
    Assert.True(set.FindExactOrSuccessor(DateTimeOffset.MinValue).ToNullable() is {} x2 && x2.Value == 42);
    Assert.True(set.FindExactOrSuccessor(DateTimeOffset.MinValue).ToNullable() is { Value: 42 });
    Assert.True(set.FindExactOrSuccessor(DateTimeOffset.MinValue).ToNullable() is (DateTimeOffset, int) x3 && x3.Value == 42 );
    Assert.True(set.FindExactOrSuccessor(DateTimeOffset.MinValue).ToNullable() is (var _, var _) x4 && x4.Value == 42 );
}

[StefanBertels]

Ok, after fiddling with ToNullable() and with refactoring tipps by Rider (ReSharper) I found a working solution:

Assert.True(set.FindExactOrSuccessor(DateTimeOffset.MinValue).Case is (DateTimeOffset a1, int b1) && b1 == 42);
Assert.True(set.FindExactOrSuccessor(DateTimeOffset.MinValue).Case is (DateTimeOffset a2, int b2 and 42));