Getting the Generic T type of a class as a String

Hi,

I have this base script, which should handle generic attributes changes when the Age within the game changes ( a game with a time switching mechanic)

I know I shouldn't be able to Serialize the fields that it contains - I should be able to serialize them in the subclasses.

BUT

What I don't know is how to return the T.ToString() value out of T just for debugging purposes. (Look at the Debug.LogWarning line: I don't know how to complete it)

T should be a simple value type like string, bool, int, float, etc. (possibly also something more complex but I don't need it for now)

Could you please help me? Shoud I declare T as a specific class? Which one?

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3. using AdvancedInspector;
4.  
5. public class AgeSpecificAttribute<T> : MonoBehaviour {
6.     public T valuePresent;
7.     public T valueAlternate;
8.  
9.     [ReadOnly]
10.     public T value;
11.  
12.     protected virtual IEnumerator Start()
13.     {
14.         // 1 frame later
15.         yield return null;
16.      
17.         SetAgeAppropriateAttribute();
18.     }
19.  
20.     public virtual T SetAgeAppropriateAttribute(Ages age)
21.     {
22.         if (AgeManager.IsPresent(age))
23.             value = valuePresent;
24.         else
25.             value = valueAlternate;
26.      
27.         //Rest is defined in subclasses
28.         if (!ApplyAgeAttribute())
29.         {
30.             Debug.LogWarning("Impossible to set " + GetType().ToString() + " to " + T)
31.         }
32.      
33.         return value;
34.     }
35.  
36.     public virtual T SetAgeAppropriateAttribute()
37.     {
38.         return SetAgeAppropriateAttribute(AgeManager.Age);
39.     }
40.  
41.     public virtual bool ApplyAgeAttribute(T ageValue)
42.     {
43.         // Implemented in subclasses
44.     }
45. }
46.  

 

Debug.Log(typeof(T).ToString());

 

Thanks, but it didn't work:
"Assets/z_Scripts/AgeSpecificAttributes/AgeSpecificAttribute.cs(30,97): error CS0119: Expression denotes a `type parameter', where a `variable', `value' or `type' was expected"

I actually needed just "value.ToString()" (value is of T type) and it's working fine.

I'm still curious about how to actually get the type of T in string. The autocompletion of ScriptInspector 3 isn't offering me any useful methods.

 

Would it be possible to define T as Nullable?

 

Sorry, you saw my post just before the edit. See the slightly modified answer.
To constrain T to nullable types, you do "where T : class" after what you want constrained, the class definition or method definition.

 

Thanks! That should definitely work

I still haven't tried but... since I mostly need T to be a value type (int, string, enum, bool, etc.), would defining T as a class still allow me to use such types?
I mean, I should be able to get a bool that can also be null. I'm not sure which language I remember this "Nullable" type to be from. Maybe Java? I can't remember. Probably it's not in Unity C# tho.

 

C# primitives are not nullable types. A string is nullable, but think of that more like an array of characters.

 

If you put a restriction on T to be a reference type, you will not be able to use this generic class with value types.

C# has a type Nullable<T> which allows value types to take a null value. By default a bool cannot be null but a Nullable<bool> can. C# provides a shorthand for this framework feature, so Nullable<bool> can be written as bool?

Making generics work with Nullable<T> is a bit weird since Nullable<T> is itself a value type. If you can provide more information about what you are trying to do we might have other ideas.