Class meta_range

Synopsis

#include <src/entt/meta/range.hpp>

template<typename Type, typename Node = typename Type::node_type>
class meta_range

Description

Iterable range to use to iterate all types of meta objects.

Template Parameters

Type - Type of meta objects returned.

Node - Type of meta nodes iterated.

Methods

	meta_range overload	Default constructor.
	meta_range overload	Constructs a meta range from a given node.
	begin	Returns an iterator to the beginning.
	cbegin	Returns an iterator to the beginning.
	cend	Returns an iterator to the end.
	end	Returns an iterator to the end.

Source

Lines 17-106 in src/entt/meta/range.hpp.

template<typename Type, typename Node = typename Type::node_type>
class meta_range {
    struct range_iterator {
        using difference_type = std::ptrdiff_t;
        using value_type = Type;
        using pointer = void;
        using reference = value_type;
        using iterator_category = std::input_iterator_tag;
        using node_type = Node;

        range_iterator() ENTT_NOEXCEPT = default;

        range_iterator(node_type *head) ENTT_NOEXCEPT
            : it{head}
        {}

        range_iterator & operator++() ENTT_NOEXCEPT {
            return (it = it->next), *this;
        }

        range_iterator operator++(int) ENTT_NOEXCEPT {
            range_iterator orig = *this;
            return ++(*this), orig;
        }

        [[nodiscard]] reference operator*() const ENTT_NOEXCEPT {
            return it;
        }

        [[nodiscard]] bool operator==(const range_iterator &other) const ENTT_NOEXCEPT {
            return other.it == it;
        }

        [[nodiscard]] bool operator!=(const range_iterator &other) const ENTT_NOEXCEPT {
            return !(*this == other);
        }

    private:
        node_type *it{};
    };

public:
    /*! @brief Node type. */
    using node_type = Node;
    /*! @brief Input iterator type. */
    using iterator = range_iterator;
    /*! @brief Constant input iterator type. */
    using const_iterator = iterator;

    /*! @brief Default constructor. */
    meta_range() ENTT_NOEXCEPT = default;

    /**
     * @brief Constructs a meta range from a given node.
     * @param head The underlying node with which to construct the range.
     */
    meta_range(node_type *head)
        : node{head}
    {}

    /**
     * @brief Returns an iterator to the beginning.
     * @return An iterator to the first meta object of the range.
     */
    [[nodiscard]] const_iterator cbegin() const ENTT_NOEXCEPT {
        return iterator{node};
    }

    /*! @copydoc cbegin */
    [[nodiscard]] iterator begin() const ENTT_NOEXCEPT {
        return cbegin();
    }

    /**
     * @brief Returns an iterator to the end.
     * @return An iterator to the element following the last meta object of the
     * range.
     */
    [[nodiscard]] const_iterator cend() const ENTT_NOEXCEPT {
        return iterator{};
    }

    /*! @copydoc cend */
    [[nodiscard]] iterator end() const ENTT_NOEXCEPT {
        return cend();
    }

private:
    node_type *node{nullptr};
};

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