Re: [PATCH] c++: Instantiate less when evaluating __is_convertible

[Marek Polacek <polacek@redhat.com>]

On Mon, Sep 26, 2022 at 05:02:36PM +0100, Jonathan Wakely wrote:
> 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.

Ack.

> I can provide a less silly test case if you like, but I don't think it
> matters for the purposes of the testsuite.

I think no need to, I'm going to use Patrick's short test.

Thanks,

Marek