How do I create a function pointer via reflection?

[mburbea]

I'm trying to write some code that wants to do some different handling depending on the T. Normally, I'd have used a delegate, but I was hoping to use func pointers for this indirection could not figure out if there was a way to do this.

static class C
{
    public static void A<T>(T val)
    {
    }
    public static void A<Ts>(Ts? val) where Ts:struct
    {
    }
}
static class NullableIndirection<T>
{
     public static delegate*<T, void> PtrForAForNullableT {get;}= ??
}

Now I can write this but it's completely horrible

PtrForAForNullableT {get;}= (delegate*<T, void>))(IntPtr)(typeof(Delegate)
            .GetField("_methodPtrAux", BindingFlags.NonPublic | BindingFlags.Instance)
            .GetValue(Delegate.CreateDelegate(typeof(Action<T>),
            Array.FindAll(typeof(C).GetMethods(), x => x.Name == "A" && x.IsGenericMethodDefinition && x.GetGenericArguments()[0].Name == "Ts")[0]
            .MakeGenericMethod(Nullable.GetUnderlyingType(typeof(T))))));

As this requires me to create a delegate and then use reflection on delegate to get the private field _methodPtrAux

Is there a better way to do this?

[danmoseley]

@steveharter is this possible..

[RevensofT]

MethodInfo mi = ...
var ptr = mi.MethodHandle.GetFunctionPointer();
// now call a delegate .ctor using that ptr

https://stackoverflow.com/questions/3915827/get-ldftn-function-pointer-in-c-sharp