let items: [Item] = ...

// Create Sorter for each attribute
let sorterForNum = Sorter<Item>(asc: false) { $0.num }
let sorterForText = Sorter<Item>(asc: true) { $0.text }

// Create Sorter with multiple conditions
let sorter = Sorter([sorterForNum, sorterForText])

// Get sorted result
let result = items.sorted(by: sorter)

/*
result: [
    Item(num: 2, text: "a"),
    Item(num: 2, text: "b"),
    Item(num: 2, text: "c"),
    Item(num: 1, text: "a"),
    Item(num: 1, text: "b"),
    Item(num: 1, text: "c")
]
*/

Sorter<Item>(asc: false) { $0.num } // Pattern 1
Sorter<Item>(asc: true) { $0.num } // Pattern 2
Sorter<Item> { $0.num } // Pattern 3

Sorter<Item> { $0.0.text < $0.1.text }

Sorter([sorter1, sorter2])
Sorter([sorter1, sorter2, sorter3])
...

let result = items.sort(by: sorter)