Casting an object with events defined to an interface type causes an internal compiler error - windows

Question

I've got an interface with a simple signature:
namespace Serial {
public interface struct ISerial
{
uint16_t func1();
uint16_t func2();
};
}
and then a class type which implements the interface
namespace Serial {
public delegate void MyEventClass();
public ref class MySerial sealed : public ISerial {
public:
event MyEventClass MyEvent;
MySerial();
...
};
}
but elsewhere, as a default parameter to a function, I try to store a reference to a type MySerial as an ISerial ^
void
begin(
Serial::ISerial ^s = ref new Serial::MySerial
);
causes: error C1001: An internal error has occurred in the compiler.
when I remove the event from the class definition, everything compiles fine. I'm finding little information on this error.

Answer 1

I verified this on VS 2013 and it works with a few minor changes (all generated based on normal compiler errors, not an ICE). I don't have VS 2015 available right now, but will log a bug if it still repros.
First the struct (should be unchanged)
namespace Serial
{
public interface struct ISerial
{
uint16_t func1();
uint16_t func2();
};
}
Then the class (couple of changes noted below):
namespace Serial
{
public delegate void MyEventClass();
public ref class MySerial sealed : public ISerial{
public:
event MyEventClass^ MyEvent;
MySerial(){}
virtual uint16_t func1() { return 42; }
virtual uint16_t func2() { return 42; }
};
}
And the usage:
void foo()
{
using namespace Serial;
ISerial^ foo = ref new MySerial();
}
Basically you need to add the hat (^) to the event type, and you need to add virtual to the methods (but do not add override).
See more here on MSDN