2 // { dg-do compile { target c++20 } }
6 static constexpr bool value = B;
7 constexpr operator bool() const { return value; }
10 using true_type = bool_constant<true>;
11 using false_type = bool_constant<false>;
20 explicit(b) X(bool_constant<b>) -> X<b>;
22 X false_ = false_type{}; // OK
23 X true_ = true_type{}; // { dg-error "explicit deduction guide" }