wil::unique_variant could automatically set its vt member when assigning a value. I have 2 ways to approach this:

1. Overload operator= directly in wil::unique_variant, so assigning a value automatically sets vt

wil::unique_variant value;
value = 42;

2. Make all union member a setter function, eg.

wil::unique_variant value;
value.lVal(42);