IDynamicInterfaceCastable and reflection #37787
Description
Some reflection problems are unsolvable for IDynamicInterfaceCastable (e.g. having GetInterfaces return the dynamic list of interfaces), but reflection APIs that deal with castability should be solvable:
using System;
using System.Runtime.InteropServices;
interface IFoo
{
void Frob();
}
[DynamicInterfaceCastableImplementation]
interface IFooImpl : IFoo
{
void IFoo.Frob() => Internal.Console.WriteLine("Hello");
}
class Program : IDynamicInterfaceCastable
{
public bool IsInterfaceImplemented(RuntimeTypeHandle interfaceType, bool throwIfNotImplemented)
{
return true;
}
public RuntimeTypeHandle GetInterfaceImplementation(RuntimeTypeHandle interfaceType)
{
return typeof(IFooImpl).TypeHandle;
}
public static void Greet(IFoo f) => f.Frob();
static void Main()
{
// Returns false
Internal.Console.WriteLine(typeof(IFoo).IsAssignableFrom(typeof(Program)).ToString());
// Throws that the interface is not implemented
var m = typeof(Program).GetInterfaceMap(typeof(IFoo));
for (int i = 0; i <= m.InterfaceMethods.Length; i++)
Internal.Console.WriteLine($"{m.InterfaceMethods[i]}: {m.TargetMethods[i]}");
}
}