About the in expression, Why can't use with array.

[Paul Backus]

On Friday, 25 October 2019 at 09:25:21 UTC, Dennis wrote:
> I can overload the 'in' operator on my types to something that 
> takes exponential time if I want, just like "+" can also be 
> overloaded to a linear time operation on e.g. BigInt.

Worth noting that `opIn` is a D1 operator overload, and thus 
deprecated as of 2.088.0.