SwiftUI view to display normal text as monospaced (fixed width characters)

MonospacedText.swift

import SwiftUI

struct MonospacedText: View {
    let content: String
    let characterWidth: CGFloat

    init(_ content: String, characterWidth: CGFloat) {
        self.content = content
        self.characterWidth = characterWidth
    }

    var body: some View {
        HStack(spacing: 0) {
            ForEach(0..<self.content.count, id: \.self) { index in
                Text("\(self.content[self.content.index(self.content.startIndex, offsetBy: index)].description)")
                    .frame(width: self.characterWidth)
            }
        }
    }
}

struct MonospacedText_Previews: PreviewProvider {
    static var previews: some View {
        MonospacedText("12:34:56:78:90", characterWidth: 20)
            .font(.largeTitle)
            .foregroundColor(.purple)
    }
}

I'm using this view to display a count down that doesn't jump around every time a number changes. If you see any way to improve its implementation, especially to automatically calculate the maximum glyph size for the current font, I'd love to know!

Apparently Font in SwiftUI has a monospacedDigit modifier. That's better than this solution if it is only for digits.