Create struct by string literal

ColorHex.swift

import UIKit

struct ColorHex: ExpressibleByStringLiteral {

    // MARK: - Type Alias.

    typealias StringLiteralType = String

    // MARK: - Private Property(ies).

    private var _value: String

    // MARK: - Public Property(ies).

    private(set) var red: CGFloat = 0
    private(set) var blue: CGFloat = 0
    private(set) var green: CGFloat = 0
    private(set) var alpha: CGFloat = 0

    var hex: String {
        _value
    }

    var uiColor: UIColor {
        .init(red: red, green: green, blue: blue, alpha: alpha)
    }

    var cgColor: CGColor {
        .init(red: red, green: green, blue: blue, alpha: alpha)
    }

    var ciColor: CIColor {
        .init(red: red, green: green, blue: blue, alpha: alpha)
    }

    // MARK: - Constructor(s).

    init(stringLiteral value: String) {
        _value = value

        if hex.hasPrefix("#") && value.count == 7 {
            let start = hex.index(hex.startIndex, offsetBy: 1)
            let hexColor = String(hex[start...])

            let scanner = Scanner(string: hexColor)
            var hexNumber: UInt64 = 0

            if scanner.scanHexInt64(&hexNumber) {
                red = CGFloat((hexNumber & 0xff0000) >> 16) / 255
                green = CGFloat((hexNumber & 0x00ff00) >> 8) / 255
                blue = CGFloat(hexNumber & 0x0000ff) / 255
            }
        } else {
            fatalError("Invalid value!")
        }
    }
}

extension ColorHex: CustomDebugStringConvertible {
    var debugDescription: String { _value }
}