[Bug c++/109136] initializer_list constructor constraint and explicit conversion operator

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109136

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[concepts] initializer_list |initializer_list
                   |constructor constraint      |constructor constraint and
                   |should require static_cast  |explicit conversion
                   |for explicit conversion     |operator
                   |operator                    |

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This has nothing to do with concepts really:
```

#include <initializer_list>

struct foo {
explicit operator int();
};

template <class From, class To>
void f(From x)
{
  std::initializer_list<To>{ x };
}
void g()
{
  f<foo, int>(foo{});
}
```
GCC accepts the above example but clang rejects it.