static inline T* error does not work @compile time

[vulptex]

Expected Behavior

See "detailed" not_bound errors

Actual Behavior

See nothing, only a linker error

gcc 12.2
clang 15

similar to:
#458

Question

I wonder myself why we have the following code (and why its so magic :-D)

template <class T>
struct abstract_type {
  struct is_not_bound {
    operator T*() const {
      using constraint_not_satisfied = is_not_bound;
      return constraint_not_satisfied{}.error();
    }
    // clang-format off
    static inline T*
 error(_ = "type is not bound, did you forget to add: 'di::bind<interface>.to<implementation>()'?");
    // clang-format on
  };
  template <class TName>
  struct named {
    struct is_not_bound {
      operator T*() const {
        using constraint_not_satisfied = is_not_bound;
        return constraint_not_satisfied{}.error();
      }
      // clang-format off
      static inline T*
   error(_ = "type is not bound, did you forget to add: 'di::bind<interface>.named(name).to<implementation>()'?");
      // clang-format on
    };
  };
};

How about replacing with a static_assert?

template <class T>
struct abstract_type {
  struct is_not_bound {
    static_assert(T::_,  "type is not bound, did you forget to add: 'di::bind<interface>.to<implementation>()'?");
  };
  template <class TName>
  struct named {
    struct is_not_bound {
     static_assert(T::_ || TName::_, "type is not bound, did you forget to add: 'di::bind<interface>.named(name).to<implementation>()'?"));
    };
  };
};