[Bug c++/67018] [c++-concepts] Failure to partially order function templates by constraints

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67018

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2015-07-28
           Assignee|unassigned at gcc dot gnu.org      |jason at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #1 from Jason Merrill <jason at gcc dot gnu.org> ---
Reduced:

template <typename T>
constexpr bool Val = true;

template <class I>
concept bool InputIterator() {
  return requires (I i) {
    requires Val <decltype(i++)>;
  };
}

template <class I>
concept bool ForwardIterator() {
  return InputIterator<I>() && true;
}

template<InputIterator>
constexpr bool f() { return false; }
template<ForwardIterator>
constexpr bool f() { return true; }

static_assert(f<int*>());