swift: modifying arrays inside dictionaries

Question

How can I easily add elements to an array inside a dictionary? It\'s always complaining with could not find member \'append\' or could not find an overloa

Answer 1

Here is what I was telling Nate Cook, in the comments for his quality answer. This is what I consider "easily [adding] elements to an array inside a dictionary":

dict["key"] = dict["key"]! + 4
dict["key"] = dict["key"] ? dict["key"]! + 4 : [4]

For now, we need to define the + operator ourselves.

@infix func +(array: T[], element: T) -> T[] {
    var copy = array
    copy += element
    return copy
}

I think this version removes too much safety; maybe define it with a compound operator?

@infix func +(array: T[]?, element: T) -> T[] {
    return array ? array! + element : [element]
}

dict["key"] = dict["key"] + 4

Finally, this is the cleanest I can get it, but I'm confused about how array values/references work in this example.

@assignment func +=(inout array: T[]?, element: T) {
    array = array + element
}

dict["key"] += 5