Any way to tell if an object is inside another class?

[Ruby The Roobster]

On Monday, 28 September 2020 at 11:40:40 UTC, k2aj wrote:
> pragma(msg, hasFieldOfType!(T, int));  //false
> pragma(msg, hasFieldOfType!(T, test)); //true

Not exactly what I meant. I more of meant is there a way to check 
if a test object is a member variable, not if it is in a 
particular class.