Useful swift extensions for `Sequence` and `Optional` with `Collection` wrapper

Extensions.swift

public extension Sequence {
    func all(_ predicate: (Element) throws -> Bool) rethrows -> Bool {
        try allSatisfy(predicate)
    }

    func any(_ predicate: (Element) throws -> Bool) rethrows -> Bool {
        try contains(where: predicate)
    }
}

public extension Sequence where Element: AdditiveArithmetic {
    func sum() -> Element {
        reduce(Element.zero, +)
    }
}

public extension Optional where Wrapped: Collection {
    var isEmpty: Bool {
        guard case let .some(val) = self else {
            return true
        }

        return val.isEmpty
    }
}

Now you can use:

let a = [1, 2, 3, 4, 5]
a.sum() // 15
a.any { $0 >= 3 } // true
a.all { $0 >= 3 } // false

let s: String? = nil
s.isEmpty // true

let a2: [Int]? = nil
a2.isEmpty // true

let a3: [Int]? = [1, 2, 3]
a3.isEmpty // false