Array tricks

Removes all duplicates of Type A

protocol X{}
struct A:X{}
struct B:X{}

var arr:[X] = [A(),B(),B(),A(),A()]

func removeDups<T>(_ arr:[T], _ condition:(_ a:T, _ b:T)->Bool)->[T]{
    var result:[T] = []
    arr.forEach{ item in
        if result.first(where:{condition(item,$0)}) == nil {result.append(item)}//append if doesn't exists
    }
    return result
}

let result = removeDups(arr,  {type(of: $0) == type(of: $1) && $1 is A})
Swift.print("result:  \(result)")//A,B,B