Compiler error for code that should be *valid*

[jayrulez]

class MyClass1
{
    private enum ResourceType { }
    private struct Buffer { }
    private struct Texture { }
    private struct Sampler { }

    private struct Resource
    {
        public ResourceType type;
        public struct
        {
            public Buffer buffer;
            public Texture texture;
            public Sampler sampler;
        };
    }
}

The code above produces a compiler error, though it is expected to compile successfully.