map_cursor.hpp

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#ifndef KAGOME_STORAGE_MAP_CURSOR_HPP
#define KAGOME_STORAGE_MAP_CURSOR_HPP

#include <optional>

#include "outcome/outcome.hpp"

namespace kagome::storage::face {

  template <typename K, typename V, typename KView = K>
  struct MapCursor {
    virtual ~MapCursor() = default;

    virtual outcome::result<bool> seekFirst() = 0;

    virtual outcome::result<bool> seek(const KView &key) = 0;

    virtual outcome::result<bool> seekLast() = 0;

    virtual bool isValid() const = 0;

    virtual outcome::result<void> next() = 0;

    virtual std::optional<K> key() const = 0;

    virtual std::optional<V> value() const = 0;
  };

}  // namespace kagome::storage::face

#endif  // KAGOME_STORAGE_MAP_CURSOR_HPP