[Bug c++/101698] [9/10/11/12 Regression] Template type conversion operator from base class preferred over matching overload

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101698

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
The overriding behaviour changed with r255605, it's just that the assertion
caused an ICE until it was removed.