// Sort a slice of structs with first class functions.
    type Album struct {
    	Title string
    	Year int
    }
    albums := []Album{
    	{"Born to Run", 1975},
    	{"WIESS",       1973},
    	{"Darkness",    1978},
    	{"Greetings",   1973},
    }
    
    less := func(a, b Album) bool { return a.Year < b.Year },
    sorted := QuickSort(less, albums).([]Album)