AMDG Dominique Devienne wrote:
In client code including the header for MyDerived, I'm using a MyPtr<MyDerived>, but the static assert below was failing. It took me a little while to figure out that in myderived.h, the MyDerived::nested_type typedef is using a forward-declared MyNestedDerived type declared in my_nested_derived.h, that the client code was not including, which was the reason is_base_of was failing with the error below (Boost 1.41, VC9). Adding a #include
fixed it. boost\type_traits\is_base_and_derived.hpp(228) : error C2139: 'MyNestedDerived' : an undefined class is not allowed as an argument to compiler intrinsic type trait '__is_base_of'
But is there a way to get a more obvious error message stating that MyNestedDerived is an incomplete type or something? In retrospect the message is not that bad, but I'm hoping there's a better way.
It seems to me that it's the compiler's job to provide a good error message in this case. I don't see that there's very much we can do inside Boost to improve it. In Christ, Steven Watanabe