meta::input_range¶

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

template <typename T>
concept input_range =
  meta::range<T> && meta::input_iterator<meta::iterator_t<T>>;

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

Concept emulation¶

namespace mgs {
namespace meta {

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

template <typename T>
constexpr auto is_input_range_v = is_input_range<T>::value;

template <typename T,
          typename = std::enable_if_t<is_input_range_v<T>>>
using input_range = T;

} // namespace meta
} // namespace mgs

Example¶

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

using namespace mgs::meta;

struct output_range {
  std::back_insert_iterator<std::string> begin();
  std::back_insert_iterator<std::string> end();
};

static_assert(is_input_range_v<std::string>, "");
static_assert(is_input_range_v<char [2]>, "");
static_assert(!is_input_range_v<output_range>, "");

See also¶