Sample implementation of a lazy value wrapper

Lazy.swift

public struct Lazy<T> {
    private let initialization: () -> T
    
    public private(set) lazy var: T = self.initialization()
    
    public init(initialization: () -> T) {
        self.initialization = initialization
    }
    
    public init(other: Lazy<T>) {
        self.init(initialization: other.initialization)
    }
    
    public mutating func reset() {
        self = Lazy(other: self)
    }
}