meta::totally_ordered_with¶

Defined in header <mgs/meta/concepts/totally_ordered_with.hpp>.

template <typename T, typename U>
concept totally_ordered_with =
  meta::totally_ordered<T> &&
  meta::totally_ordered<U> &&
  meta::common_reference_with<
    std::remove_reference_t<T> const&,
    std::remove_reference_t<U> const&> &&
  meta::totally_ordered<
    meta::common_reference_t<
      std::remove_reference_t<T> const&,
      std::remove_reference_t<U> const&>> &&
  meta::equality_comparable_with<T, U> &&
  requires(std::remove_reference_t<T> const& t,
           std::remove_reference_t<U> const& u) {
    { t <  u } -> meta::boolean;
    { t >  u } -> meta::boolean;
    { t <= u } -> meta::boolean;
    { t >= u } -> meta::boolean;
    { u <  t } -> meta::boolean;
    { u >  t } -> meta::boolean;
    { u <= t } -> meta::boolean;
    { u >= t } -> meta::boolean;
  };

Pre-C++20 implementation of the std::totally_ordered_with concept.

Concept emulation¶

namespace mgs {
namespace meta {

template <typename T, typename U>
struct is_totally_ordered_with { /* ... */ };

template <typename T, typename U>
constexpr auto is_totally_ordered_with_v =
                  is_totally_ordered_with<T, U>::value;

template <typename T, typename U,
          typename = std::enable_if_t<is_totally_ordered_with_v<T, U>>>
using totally_ordered_with = T;

} // namespace meta
} // namespace mgs

Example¶

#include <mgs/meta/concepts/totally_ordered_with.hpp>

using namespace mgs::meta;

static_assert(is_totally_ordered_with_v<int, float>, "");
static_assert(!is_totally_ordered_with_v<int, std::vector<int>>, "");

See also¶