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)
