Extend array types using where clause in Swift

Question

I\'d like to use the Accelerate framework to extend [Float] and [Double] but each of these requires a different implementation.

I tried the obvious:

Answer 1

How about

extension CollectionType where Generator.Element == Double {

}

Or If you want a little bit more:

protocol ArithmeticType {
    func +(lhs: Self, rhs: Self) -> Self
    func -(lhs: Self, rhs: Self) -> Self
    func *(lhs: Self, rhs: Self) -> Self
    func /(lhs: Self, rhs: Self) -> Self
}

extension Double : ArithmeticType {}
extension Float : ArithmeticType {}

extension SequenceType where Generator.Element : protocol {
    var sum : Generator.Element {
        return reduce(0.0, combine: +)
    }

    var product : Generator.Element {
        return reduce(1.0, combine: *)
    }
}


stride(from: 1.0, through: 10.0, by: 1.0).sum   // 55
[1.5, 2.0, 3.5, 4.0, 5.5].product               // 231

Works with Double and Float or any other type that you conform to the protocols ArithmeticType and FloatLiteralConvertible. If you need to access specific indices of your array, change SequenceType to CollectionType as you cannot do this with a sequence.