Strictly typed JSON representation

Question

I would like to be specific in parameter types or write something like this:

Test test = (Json<Test>)"{\"age\": 46}";

Where:

public class Test 
{
    public int Age { get; set; }
}

My helper is:

public struct Json<T> 
{
    public static implicit operator string(Json<T> json) => json.JObject.ToString();
    public static explicit operator Json<T>(string json) => new Json<T>(json);

    public static implicit operator T(Json<T> json) => json.JObject.ToObject<T>();
    public static implicit operator Json<T>(T obj) => new Json<T>(JObject.FromObject(obj));

    static readonly JObject Default = JObject.FromObject(new { });

    Json(string json) : this(JObject.Parse(json)) { } 
    Json(JObject jObject) : this() => _jObject = jObject ?? 
        throw new ArgumentNullException(nameof(jObject));

    JObject JObject => _jObject ?? Default;
    readonly JObject _jObject;
}

Answer 1

The missing part is a JsonConverter:

[JsonConverter(typeof(JsonTConverter))]
public struct Json<T> 
{

And:

public class JsonTConverter : JsonConverter
{
    public override bool CanConvert(Type objectType) =>
        objectType.IsConstructedGenericType &&
        objectType.GetGenericTypeDefinition() == typeof(Json<>);

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer) =>
        Activator.CreateInstance(objectType, reader.Value);

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer) =>
        writer.WriteValue(value.ToString());
}