You might be confusing types and traits (typeclasses) here; it's not about `YourType` but rather when you want to make a Vec of heterogenous types that share a

You might be confusing types and traits (typeclasses) here; it's not about `YourType` but rather when you want to make a Vec of heterogenous types that share a trait. That's when the question of object safety (and needing a vtable) arises.