ThemeManager-TargetAction-Wrapper.swift

protocol TargetAction {
    associatedtype Theme: ThemeProtocol
    func applyTheme(_ theme: Theme)
}

struct AnyTargetActionWrapper<Theme: ThemeProtocol>: TargetAction {
    private let _applyTheme: (Theme) -> ()

    init<Target: AnyObject>(
        target: Target,
        action: @escaping (Target) -> (Theme) -> ()
    ) {
        self._applyTheme = { [weak target] theme in
            guard let target = target else { return; }
            action(target)(theme)
        }
    }

    func applyTheme(_ theme: Theme) -> () {
        _applyTheme(theme)
    }
}