Binary operator '+' cannot be applied to two 'T' operands

Question

I am using Generics to add different types like Int, Double, Float, etc. I used the code below but I\'m getting error \"Binary operator \'+\' cannot be applied to two \'T\'

Answer 1

Swift doesn't know that the generic type T has a '+' operator. You can't use + on any type: e.g. on two view controllers + doesn't make too much sense

You can use protocol conformance to let swift know some things about your type!

I had a go in a playground and this is probably what you are looking for :)

protocol Addable {
    func +(lhs: Self, rhs: Self) -> Self
}

func add(num1: T, _ num2: T) -> T {
    return num1 + num2
}

extension Int: Addable {}
extension Double: Addable {}
extension Float: Addable {}

add(3, 0.2)

Let me know if you need any of the concepts demonstrated here explained