[Bug c++/87145] [7/8/9 Regression] Implicit conversion to scoped enum fails: "error: taking address of temporary/rvalue"

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87145

--- Comment #6 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Slightly different testcase:

struct S {
  int val;

  constexpr operator int() const {
    return static_cast<int>(val);
  }
};

template<int N>
struct F { };

template<unsigned N>
constexpr void foo() {
  F<S{N}> f;
}

int
main()
{
  foo<2>();
}