Property wrapper for storing any `Codable` data structure into a `UserDefaults` store.

DataStorage.swift

import SwiftUI

@propertyWrapper public struct DataStorage<Value: Codable>: DynamicProperty {

    // MARK: - Private Properties

    private var defaultValue: Value
    private var storageKey: String
    private var store: UserDefaults
    private var data: AppStorage<Data?>

    // MARK: - Internal Properties

    public var wrappedValue: Value {
        get {
            guard
                let data = data.wrappedValue,
                let value = try? JSONDecoder().decode(Value.self, from: data) as Value else {
                return defaultValue
            }

            return value
        }
        nonmutating set {
            guard let data = try? JSONEncoder().encode(newValue) else {
                return
            }

            self.store.set(data, forKey: self.storageKey)
            self.data.wrappedValue = data
        }
    }

    public var projectedValue: Binding<Value> {
        Binding<Value>(get: { self.wrappedValue },
                       set: { newValue in self.wrappedValue = newValue })
    }

    // MARK: - Lifecycle

    /// Property wrapper for storing any `Codable` data structure into a `UserDefaults` store.
    /// 
    /// Example usage:
    /// ```
    /// @DataStorage("todoList", store: .standard) private var todos: [String] = []
    /// ```
    public init(wrappedValue: Value, _ storageKey: String, store: UserDefaults = .standard) {
        defaultValue = wrappedValue
        self.storageKey = storageKey
        self.store = store
        data = AppStorage(storageKey, store: store)
    }
}