Why MapIf and BindIf have T as return type?

[marcinjahn]

Normally, both Bind and Map can return different type (K) than the input type (T).
However, both BindIf and MapIf require both input and output to be T. Why is that? Is it a mistake?

[marcinjahn]

Alright, I can answer this myself. It's due to the fact that the MapIf and BindIf might return either the result of provided func, or (if condition is false), the original result. Therefore, both func and provided result must be of the same type.