On Fri, 26 Aug 2022, 02:06 Patrick Palka via Libstdc++, <
libstdc++@gcc.gnu.org> wrote:

> Tested on x86_64-pc-linux-gnu, does this look OK for trunk?
>
> libstdc++-v3/ChangeLog:
>
>         * testsuite/20_util/logical_traits/requirements/base_classes.cc:
> New test.
> ---
>  .../requirements/base_classes.cc              | 37 +++++++++++++++++++
>  1 file changed, 37 insertions(+)
>  create mode 100644
> libstdc++-v3/testsuite/20_util/logical_traits/requirements/base_classes.cc
>
> diff --git
> a/libstdc++-v3/testsuite/20_util/logical_traits/requirements/base_classes.cc
> b/libstdc++-v3/testsuite/20_util/logical_traits/requirements/base_classes.cc
> new file mode 100644
> index 00000000000..6699037bb14
> --- /dev/null
> +++
> b/libstdc++-v3/testsuite/20_util/logical_traits/requirements/base_classes.cc
> @@ -0,0 +1,37 @@
> +// { dg-do compile { target c++17 } }
> +
> +#include <utility>
>

<type_traits> instead

OK with that change, thanks.


+
> +using std::true_type;
> +using std::false_type;
> +
> +template<int> struct T : std::true_type { };
> +template<int> struct F : std::false_type { };
> +
> +// [meta.logical]/5: The specialization conjunction<B_1, ..., B_n> has a
> +// public and unambiguous base that is either:
> +//   - the first type B_i in the list true_type, B_1, ..., B_n for which
> +//       bool(B_i::value) is false, or
> +//   - if there is no such Bi, the last type in the list.
> +
> +static_assert(std::is_base_of_v<true_type, std::conjunction<>>);
> +static_assert(std::is_base_of_v<T<0>, std::conjunction<T<0>>>);
> +static_assert(std::is_base_of_v<F<0>, std::conjunction<F<0>>>);
> +static_assert(std::is_base_of_v<T<1>, std::conjunction<T<0>, T<1>>>);
> +static_assert(std::is_base_of_v<F<0>, std::conjunction<F<0>, F<1>>>);
> +static_assert(std::is_base_of_v<F<0>, std::conjunction<T<0>, F<0>,
> F<1>>>);
> +static_assert(std::is_base_of_v<F<0>, std::conjunction<T<0>, F<0>, T<1>,
> F<1>>>);
> +
> +// [meta.logical]/10: The specialization disjunction<B_1, ..., B_n> has a
> +// public and unambiguous base that is either:
> +//   - the first type B_i in the list false_type, B_1, ..., B_n for which
> +//       bool(B_i::value) is true, or
> +//   - if there is no such Bi, the last type in the list.
> +
> +static_assert(std::is_base_of_v<false_type, std::disjunction<>>);
> +static_assert(std::is_base_of_v<T<0>, std::disjunction<T<0>>>);
> +static_assert(std::is_base_of_v<F<0>, std::disjunction<F<0>>>);
> +static_assert(std::is_base_of_v<T<0>, std::disjunction<T<0>, T<1>>>);
> +static_assert(std::is_base_of_v<F<1>, std::disjunction<F<0>, F<1>>>);
> +static_assert(std::is_base_of_v<T<0>, std::disjunction<T<0>, F<0>,
> F<1>>>);
> +static_assert(std::is_base_of_v<T<0>, std::disjunction<T<0>, F<0>, T<1>,
> F<1>>>);
> --
> 2.37.2.382.g795ea8776b
>
>