private Func <TypeDefinition[]> DefineClrHandleStructInternal(ClangStructInfo structInfo, int?bits = null)
        {
            if (structInfo.Size > 0)
            {
                throw new NotImplementedException();
            }

            var structName = structInfo.Name;

            if (TypeRedirects.TryGetValue(structName, out var rename))
            {
                structName = rename;
            }
            if (Module.GetType(structName)?.Resolve() != null)
            {
                return(null);
            }

            // handle type
            var handleDef = Module.DefineType(structName,
                                              PublicSealedStructTypeAttributes, size: 0);

            handleDef.SetCustomAttribute(() => new BinderGeneratedAttribute());

            //handleDef.SetCustomAttribute(StructLayoutSequentialAttributeInfo);
            var handleInterface = IHandleGtd.MakeGenericInstanceType(handleDef);

            handleDef.AddInterfaceImplementation(handleInterface);
            var handlePointerType = handleDef.MakePointerType();
            var inputTypes        = bits == null
                                ? TypeArrayOfSingularVoidPointer
                                : bits == 64
                                        ? TypeArrayOfSingularULong
                                        : TypeArrayOfSingularUInt;
            var castMethod = handleDef.DefineMethod("Cast", PublicStaticMethodAttributes,
                                                    handlePointerType, inputTypes);

            SetMethodInliningAttributes(castMethod);
            castMethod.GenerateIL(il => {
                il.Emit(OpCodes.Ldarg_0);
                il.Emit(OpCodes.Ret);
            });
            var handleType = handleDef.CreateType();

            return(() => new[] { handleType });
        }
        private bool IsHandleType(TypeReference t)
        {
            TypeReference interfaceType;

            if (t.IsPrimitive() || t.IsIndirect())
            {
                return(false);
            }

            try {
                interfaceType = IHandleGtd.MakeGenericInstanceType(t);
            }
            catch {
                return(false);
            }

            var result = t.GetInterfaces().Contains(interfaceType);             //.Any( i => i.Is(interfaceType));

            return(result);
        }