Forward declare in nested namespace

Question

I'm writing a class (in a header file) that requires the following method:

static const foo::bar::clz* getSomething(void);

As I don't want to pollute the header file with an #include I choose to forward declare clz:

namespace foo
{
    namespace bar
    {
        class clz;
    }
}

But that's rather clumsy too. Is there a cuter way of doing this in C++11? Something along the lines of

class foo::bar::clz;

It would be nicer still if you didn't have to anticipate whether or not it's implemented as a class, struct or union. Have the C++11 grammarians covered that one too? (typename auto could be a candidate but I'm not an expert in C++ grammar).

Answer 1

The nested namespaces can't be avoided.

As for class vs. struct vs. union, partially: class and struct can be used interchangeably. If it's a union, it must be declared as such.