[Bug c++/102157] floating-integral conversions is not permitted in the user-defined conversion sequence in converted constant expression

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102157

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2021-09-01

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
There are two issues here really (both accepts invalid).
First is binding to a temp is invalid:
struct A{
    constexpr A(double const &rf){}
};
template<class T, T B>
struct C{};
int main() {
    C<A,0.> b;
}
----- CUT ----
Second is the conversion is also invalid:
struct A{
    constexpr A(double rf){}
};
template<class T, T B>
struct C{};
int main() {
    C<A,0> b;
}