Feature Request C# 9.0 Function Pointers

First off, I want to say I've been keeping an eye on the C# 9 function pointers, and I really appreciate the efforts the scripting team has made so far with its support. I was excited to use them in Burst with the hope that they can be used to overcome the generic delegate limitation when using

FunctionPointer

in non-bursted code.

Currently running Unity 2021.2.0a13 with Burst 1.6.0-pre.2, I am running into

Burst error BC1054: Unable to resolve type `method System.Int32 *(System.Int32). Reason: Unknown.`

Here's a snip of the failing Job:

Code (CSharp):

1. [BurstCompile]
2. public unsafe struct CallFuncJob : IJob
3. {
4.     [NativeDisableUnsafePtrRestriction]
5.     public IntPtr FuncPtr;
6.     public NativeArray<int> In;
7.     public NativeArray<int> Out;
8.  
9.     public void Execute()
10.     {
11.         Out[0] = ((delegate* unmanaged[Cdecl]<int, int>)FuncPtr)(In[0]);
12.     }
13. }

 

Ideally, I hope it can support something like this:

Code (CSharp):

1. public unsafe struct BurstFunc<T, TResult>
2.   where T : struct
3.   where TResult : struct
4. {
5.   readonly delegate* unmanaged[Cdecl]<T, TResult> _ptr;
6.  
7.   public BurstFunc(IntPtr ptr)
8.   {
9.     _ptr = ptr;
10.   }
11.  
12.   public TResult Invoke(T arg0) => _ptr(arg0);
13.  
14.   public static BurstFunc<T, TResult> Compile(Func<T, TResult> func)
15.   {
16.     var ptr = BurstCompiler.CompileFunctionPointer(func);
17.     return new BurstFunc<T, TResult>(ptr.Value);
18.   }
19. }

 

There's also this now that I am looking into after a tip from elsewhere on these here fora:
https://docs.unity3d.com/Packages/c...al/docs/AdvancedUsages.html#function-pointers