meta::regular¶

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

template <typename T>
concept regular = meta::semiregular<T> && meta::equality_comparable<T>;

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

Concept emulation¶

namespace mgs {
namespace meta {

template <typename T>
struct is_regular { /* ... */ };

template <typename T>
constexpr auto is_regular_v = is_regular<T>::value;

template <typename T,
          typename = std::enable_if_t<is_regular_v<T>>>
using regular = T;

} // namespace meta
} // namespace mgs

Example¶

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

using namespace mgs::meta;

// no equality operator
struct semiregular {};

static_assert(is_regular_v<std::vector<int>>, "");
static_assert(is_regular_v<int>, "");
static_assert(!is_regular_v<semiregular>, "");

See also¶