Remove array duplicates with reduce()

remove_duplicates_reduce

let array = ["P","Q","R","S","T","P","R","A","T","B","C","P","P","P","P","P","C","P","P","J"]

let unique = array.reduce([String](), combine: { (array, value) -> [String] in
    var result = array
    if (!contains(array, value)) {
        result.append(value)
    }
    return result
})

println(unique) // [P, Q, R, S, T, A, B, C, J]

http://sketchytech.blogspot.co.uk/2014/08/pure-swift-little-deeper-into-generics.html