type_of

universe feature to determine the compile-time type of an expression.

This is to be called without an actual type passed to `T`, but `T` should be
inferred from the actual value argument `_`.

The value argument is evaluated and ignored.

The result is the type of the value argument boxed into a ref value and returned
as a value of type `Type`.

examples:

`type_of "bla"` is `String`
`type_of (panic "***")` will terminate