Error C2621 when union contains array of template class in VS2013 - c++

Question

I have some C++ code I'm trying to compile in Visual Studio 2013, but I'm running into an error. Here's a simplified testcase that demonstrates the problem:
template <typename SomeEnum>
struct Inner {
SomeEnum variant;
int innerVal;
};
template <typename SomeEnum>
struct Outer {
int outerVal;
union {
Inner<SomeEnum> inners[10];
unsigned char data[20];
};
};
enum MyEnum {
VAR1,
VAR2
};
int main() {
Outer<MyEnum> outer;
return 0;
}
This gives me the error main.cpp(11): error C2621: 'Outer<MyEnum>::inners' : illegal union member; type 'Inner<SomeEnum>' has a copy constructor. It seems like Inner<SomeEnum> should be as POD as they come. Is this a known problem, or is the code invalid for a reason of which I'm not aware? Some Googling yielded no results on the issue.
The example compiles if I either Inner not a template class or if inners is not an array, but unfortunately neither of those is an option for my actual code. Are there any other ways I could accomplish the same thing?

Answer 1

It works on ideone.com, leading me to think it may be a VS2013 bug. You could try VS2015 if you can.
A possible workaround is to explicitly specialize for each enum you want to use.
Adding this after the MyEnum definition:
template <>
struct Inner<MyEnum> {
MyEnum variant;
int innerVal;
}
Makes the error go away for some reason. Obviously that will lead to a ton of duplicated code, which is what templates are trying to stop. You could possibly write a macro (ugh) to make this template specialization for you.