On Mon, 26 Sept 2022 at 16:23, Marek Polacek wrote: > > Jon reported that evaluating __is_convertible in this test leads to > instantiating char_traits<char>::eq, which is invalid (because we > are trying to call a member function on a char)
N.B. in the original code wasn't trying to do something dumb like call a member function on a char, but it was using basic_string_view<X> where X is a class type without an operator== and so char_traits<X>::eq was invalid. I changed it to just use basic_string_view<char> and changed char_traits::eq to do something different, that was invalid for char. I can provide a less silly test case if you like, but I don't think it matters for the purposes of the testsuite.
