[Bug c++/63452] Cross class calling (pure virtual)

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63452

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |INVALID

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
You have two different definitions of foo::Impl, which violates the One
Definition Rule.

The linker only keeps one version of the symbol

You need to rename one of the Impl base classes, or put them in different
namespaces (e.g. two different anonymous namespaces)