forked from Green-Sky/tomato
Green Sky
5c7231b7a3
git-subtree-dir: external/entt/entt git-subtree-split: fef921132cae7588213d0f9bcd2fb9c8ffd8b7fc
896 lines
32 KiB
C++
896 lines
32 KiB
C++
#ifndef ENTT_CONTAINER_DENSE_SET_HPP
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#define ENTT_CONTAINER_DENSE_SET_HPP
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#include <cmath>
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#include <cstddef>
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#include <functional>
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#include <iterator>
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#include <limits>
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#include <memory>
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#include <tuple>
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#include <type_traits>
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#include <utility>
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#include <vector>
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#include "../config/config.h"
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#include "../core/compressed_pair.hpp"
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#include "../core/memory.hpp"
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#include "../core/type_traits.hpp"
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#include "fwd.hpp"
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namespace entt {
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/**
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* @cond TURN_OFF_DOXYGEN
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* Internal details not to be documented.
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*/
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namespace internal {
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template<typename It>
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class dense_set_iterator final {
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template<typename>
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friend class dense_set_iterator;
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public:
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using value_type = typename It::value_type::second_type;
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using pointer = const value_type *;
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using reference = const value_type &;
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using difference_type = std::ptrdiff_t;
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using iterator_category = std::random_access_iterator_tag;
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constexpr dense_set_iterator() noexcept
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: it{} {}
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constexpr dense_set_iterator(const It iter) noexcept
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: it{iter} {}
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template<typename Other, typename = std::enable_if_t<!std::is_same_v<It, Other> && std::is_constructible_v<It, Other>>>
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constexpr dense_set_iterator(const dense_set_iterator<Other> &other) noexcept
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: it{other.it} {}
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constexpr dense_set_iterator &operator++() noexcept {
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return ++it, *this;
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}
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constexpr dense_set_iterator operator++(int) noexcept {
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dense_set_iterator orig = *this;
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return ++(*this), orig;
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}
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constexpr dense_set_iterator &operator--() noexcept {
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return --it, *this;
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}
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constexpr dense_set_iterator operator--(int) noexcept {
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dense_set_iterator orig = *this;
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return operator--(), orig;
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}
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constexpr dense_set_iterator &operator+=(const difference_type value) noexcept {
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it += value;
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return *this;
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}
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constexpr dense_set_iterator operator+(const difference_type value) const noexcept {
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dense_set_iterator copy = *this;
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return (copy += value);
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}
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constexpr dense_set_iterator &operator-=(const difference_type value) noexcept {
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return (*this += -value);
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}
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constexpr dense_set_iterator operator-(const difference_type value) const noexcept {
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return (*this + -value);
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}
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[[nodiscard]] constexpr reference operator[](const difference_type value) const noexcept {
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return it[value].second;
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}
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[[nodiscard]] constexpr pointer operator->() const noexcept {
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return std::addressof(it->second);
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}
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[[nodiscard]] constexpr reference operator*() const noexcept {
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return *operator->();
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}
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template<typename ILhs, typename IRhs>
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friend constexpr std::ptrdiff_t operator-(const dense_set_iterator<ILhs> &, const dense_set_iterator<IRhs> &) noexcept;
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template<typename ILhs, typename IRhs>
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friend constexpr bool operator==(const dense_set_iterator<ILhs> &, const dense_set_iterator<IRhs> &) noexcept;
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template<typename ILhs, typename IRhs>
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friend constexpr bool operator<(const dense_set_iterator<ILhs> &, const dense_set_iterator<IRhs> &) noexcept;
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private:
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It it;
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};
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template<typename ILhs, typename IRhs>
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[[nodiscard]] constexpr std::ptrdiff_t operator-(const dense_set_iterator<ILhs> &lhs, const dense_set_iterator<IRhs> &rhs) noexcept {
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return lhs.it - rhs.it;
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}
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template<typename ILhs, typename IRhs>
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[[nodiscard]] constexpr bool operator==(const dense_set_iterator<ILhs> &lhs, const dense_set_iterator<IRhs> &rhs) noexcept {
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return lhs.it == rhs.it;
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}
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template<typename ILhs, typename IRhs>
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[[nodiscard]] constexpr bool operator!=(const dense_set_iterator<ILhs> &lhs, const dense_set_iterator<IRhs> &rhs) noexcept {
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return !(lhs == rhs);
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}
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template<typename ILhs, typename IRhs>
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[[nodiscard]] constexpr bool operator<(const dense_set_iterator<ILhs> &lhs, const dense_set_iterator<IRhs> &rhs) noexcept {
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return lhs.it < rhs.it;
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}
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template<typename ILhs, typename IRhs>
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[[nodiscard]] constexpr bool operator>(const dense_set_iterator<ILhs> &lhs, const dense_set_iterator<IRhs> &rhs) noexcept {
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return rhs < lhs;
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}
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template<typename ILhs, typename IRhs>
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[[nodiscard]] constexpr bool operator<=(const dense_set_iterator<ILhs> &lhs, const dense_set_iterator<IRhs> &rhs) noexcept {
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return !(lhs > rhs);
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}
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template<typename ILhs, typename IRhs>
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[[nodiscard]] constexpr bool operator>=(const dense_set_iterator<ILhs> &lhs, const dense_set_iterator<IRhs> &rhs) noexcept {
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return !(lhs < rhs);
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}
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template<typename It>
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class dense_set_local_iterator final {
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template<typename>
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friend class dense_set_local_iterator;
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public:
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using value_type = typename It::value_type::second_type;
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using pointer = const value_type *;
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using reference = const value_type &;
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using difference_type = std::ptrdiff_t;
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using iterator_category = std::forward_iterator_tag;
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constexpr dense_set_local_iterator() noexcept
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: it{},
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offset{} {}
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constexpr dense_set_local_iterator(It iter, const std::size_t pos) noexcept
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: it{iter},
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offset{pos} {}
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template<typename Other, typename = std::enable_if_t<!std::is_same_v<It, Other> && std::is_constructible_v<It, Other>>>
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constexpr dense_set_local_iterator(const dense_set_local_iterator<Other> &other) noexcept
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: it{other.it},
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offset{other.offset} {}
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constexpr dense_set_local_iterator &operator++() noexcept {
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return offset = it[offset].first, *this;
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}
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constexpr dense_set_local_iterator operator++(int) noexcept {
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dense_set_local_iterator orig = *this;
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return ++(*this), orig;
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}
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[[nodiscard]] constexpr pointer operator->() const noexcept {
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return std::addressof(it[offset].second);
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}
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[[nodiscard]] constexpr reference operator*() const noexcept {
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return *operator->();
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}
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[[nodiscard]] constexpr std::size_t index() const noexcept {
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return offset;
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}
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private:
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It it;
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std::size_t offset;
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};
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template<typename ILhs, typename IRhs>
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[[nodiscard]] constexpr bool operator==(const dense_set_local_iterator<ILhs> &lhs, const dense_set_local_iterator<IRhs> &rhs) noexcept {
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return lhs.index() == rhs.index();
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}
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template<typename ILhs, typename IRhs>
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[[nodiscard]] constexpr bool operator!=(const dense_set_local_iterator<ILhs> &lhs, const dense_set_local_iterator<IRhs> &rhs) noexcept {
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return !(lhs == rhs);
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}
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} // namespace internal
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/**
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* Internal details not to be documented.
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* @endcond
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*/
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/**
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* @brief Associative container for unique objects of a given type.
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*
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* Internally, elements are organized into buckets. Which bucket an element is
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* placed into depends entirely on its hash. Elements with the same hash code
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* appear in the same bucket.
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*
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* @tparam Type Value type of the associative container.
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* @tparam Hash Type of function to use to hash the values.
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* @tparam KeyEqual Type of function to use to compare the values for equality.
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* @tparam Allocator Type of allocator used to manage memory and elements.
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*/
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template<typename Type, typename Hash, typename KeyEqual, typename Allocator>
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class dense_set {
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static constexpr float default_threshold = 0.875f;
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static constexpr std::size_t minimum_capacity = 8u;
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using node_type = std::pair<std::size_t, Type>;
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using alloc_traits = std::allocator_traits<Allocator>;
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static_assert(std::is_same_v<typename alloc_traits::value_type, Type>, "Invalid value type");
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using sparse_container_type = std::vector<std::size_t, typename alloc_traits::template rebind_alloc<std::size_t>>;
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using packed_container_type = std::vector<node_type, typename alloc_traits::template rebind_alloc<node_type>>;
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template<typename Other>
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[[nodiscard]] std::size_t value_to_bucket(const Other &value) const noexcept {
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return fast_mod(static_cast<size_type>(sparse.second()(value)), bucket_count());
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}
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template<typename Other>
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[[nodiscard]] auto constrained_find(const Other &value, std::size_t bucket) {
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for(auto it = begin(bucket), last = end(bucket); it != last; ++it) {
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if(packed.second()(*it, value)) {
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return begin() + static_cast<typename iterator::difference_type>(it.index());
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}
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}
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return end();
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}
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template<typename Other>
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[[nodiscard]] auto constrained_find(const Other &value, std::size_t bucket) const {
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for(auto it = cbegin(bucket), last = cend(bucket); it != last; ++it) {
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if(packed.second()(*it, value)) {
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return cbegin() + static_cast<typename iterator::difference_type>(it.index());
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}
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}
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return cend();
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}
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template<typename Other>
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[[nodiscard]] auto insert_or_do_nothing(Other &&value) {
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const auto index = value_to_bucket(value);
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if(auto it = constrained_find(value, index); it != end()) {
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return std::make_pair(it, false);
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}
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packed.first().emplace_back(sparse.first()[index], std::forward<Other>(value));
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sparse.first()[index] = packed.first().size() - 1u;
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rehash_if_required();
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return std::make_pair(--end(), true);
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}
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void move_and_pop(const std::size_t pos) {
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if(const auto last = size() - 1u; pos != last) {
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size_type *curr = sparse.first().data() + value_to_bucket(packed.first().back().second);
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packed.first()[pos] = std::move(packed.first().back());
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for(; *curr != last; curr = &packed.first()[*curr].first) {}
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*curr = pos;
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}
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packed.first().pop_back();
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}
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void rehash_if_required() {
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if(size() > (bucket_count() * max_load_factor())) {
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rehash(bucket_count() * 2u);
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}
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}
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public:
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/*! @brief Key type of the container. */
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using key_type = Type;
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/*! @brief Value type of the container. */
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using value_type = Type;
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/*! @brief Unsigned integer type. */
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using size_type = std::size_t;
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/*! @brief Type of function to use to hash the elements. */
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using hasher = Hash;
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/*! @brief Type of function to use to compare the elements for equality. */
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using key_equal = KeyEqual;
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/*! @brief Allocator type. */
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using allocator_type = Allocator;
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/*! @brief Random access iterator type. */
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using iterator = internal::dense_set_iterator<typename packed_container_type::iterator>;
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/*! @brief Constant random access iterator type. */
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using const_iterator = internal::dense_set_iterator<typename packed_container_type::const_iterator>;
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/*! @brief Forward iterator type. */
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using local_iterator = internal::dense_set_local_iterator<typename packed_container_type::iterator>;
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/*! @brief Constant forward iterator type. */
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using const_local_iterator = internal::dense_set_local_iterator<typename packed_container_type::const_iterator>;
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/*! @brief Default constructor. */
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dense_set()
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: dense_set{minimum_capacity} {}
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/**
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* @brief Constructs an empty container with a given allocator.
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* @param allocator The allocator to use.
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*/
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explicit dense_set(const allocator_type &allocator)
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: dense_set{minimum_capacity, hasher{}, key_equal{}, allocator} {}
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/**
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* @brief Constructs an empty container with a given allocator and user
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* supplied minimal number of buckets.
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* @param cnt Minimal number of buckets.
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* @param allocator The allocator to use.
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*/
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dense_set(const size_type cnt, const allocator_type &allocator)
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: dense_set{cnt, hasher{}, key_equal{}, allocator} {}
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/**
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* @brief Constructs an empty container with a given allocator, hash
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* function and user supplied minimal number of buckets.
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* @param cnt Minimal number of buckets.
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* @param hash Hash function to use.
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* @param allocator The allocator to use.
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*/
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dense_set(const size_type cnt, const hasher &hash, const allocator_type &allocator)
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: dense_set{cnt, hash, key_equal{}, allocator} {}
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/**
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* @brief Constructs an empty container with a given allocator, hash
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* function, compare function and user supplied minimal number of buckets.
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* @param cnt Minimal number of buckets.
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* @param hash Hash function to use.
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* @param equal Compare function to use.
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* @param allocator The allocator to use.
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*/
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explicit dense_set(const size_type cnt, const hasher &hash = hasher{}, const key_equal &equal = key_equal{}, const allocator_type &allocator = allocator_type{})
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: sparse{allocator, hash},
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packed{allocator, equal},
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threshold{default_threshold} {
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rehash(cnt);
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}
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/*! @brief Default copy constructor. */
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dense_set(const dense_set &) = default;
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/**
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* @brief Allocator-extended copy constructor.
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* @param other The instance to copy from.
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* @param allocator The allocator to use.
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*/
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dense_set(const dense_set &other, const allocator_type &allocator)
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: sparse{std::piecewise_construct, std::forward_as_tuple(other.sparse.first(), allocator), std::forward_as_tuple(other.sparse.second())},
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packed{std::piecewise_construct, std::forward_as_tuple(other.packed.first(), allocator), std::forward_as_tuple(other.packed.second())},
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threshold{other.threshold} {}
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/*! @brief Default move constructor. */
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dense_set(dense_set &&) noexcept(std::is_nothrow_move_constructible_v<compressed_pair<sparse_container_type, hasher>> &&std::is_nothrow_move_constructible_v<compressed_pair<packed_container_type, key_equal>>) = default;
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/**
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* @brief Allocator-extended move constructor.
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* @param other The instance to move from.
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* @param allocator The allocator to use.
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*/
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dense_set(dense_set &&other, const allocator_type &allocator)
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: sparse{std::piecewise_construct, std::forward_as_tuple(std::move(other.sparse.first()), allocator), std::forward_as_tuple(std::move(other.sparse.second()))},
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packed{std::piecewise_construct, std::forward_as_tuple(std::move(other.packed.first()), allocator), std::forward_as_tuple(std::move(other.packed.second()))},
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threshold{other.threshold} {}
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/**
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* @brief Default copy assignment operator.
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* @return This container.
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*/
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dense_set &operator=(const dense_set &) = default;
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/**
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* @brief Default move assignment operator.
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* @return This container.
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*/
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dense_set &operator=(dense_set &&) noexcept(std::is_nothrow_move_assignable_v<compressed_pair<sparse_container_type, hasher>> &&std::is_nothrow_move_assignable_v<compressed_pair<packed_container_type, key_equal>>) = default;
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/**
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* @brief Returns the associated allocator.
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* @return The associated allocator.
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*/
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[[nodiscard]] constexpr allocator_type get_allocator() const noexcept {
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return sparse.first().get_allocator();
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}
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/**
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* @brief Returns an iterator to the beginning.
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*
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* The returned iterator points to the first instance of the internal array.
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* If the array is empty, the returned iterator will be equal to `end()`.
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*
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* @return An iterator to the first instance of the internal array.
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*/
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[[nodiscard]] const_iterator cbegin() const noexcept {
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return packed.first().begin();
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}
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/*! @copydoc cbegin */
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[[nodiscard]] const_iterator begin() const noexcept {
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return cbegin();
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}
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/*! @copydoc begin */
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[[nodiscard]] iterator begin() noexcept {
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return packed.first().begin();
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}
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/**
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* @brief Returns an iterator to the end.
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*
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* The returned iterator points to the element following the last instance
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* of the internal array. Attempting to dereference the returned iterator
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* results in undefined behavior.
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*
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* @return An iterator to the element following the last instance of the
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* internal array.
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*/
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[[nodiscard]] const_iterator cend() const noexcept {
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return packed.first().end();
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}
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/*! @copydoc cend */
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[[nodiscard]] const_iterator end() const noexcept {
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return cend();
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}
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/*! @copydoc end */
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[[nodiscard]] iterator end() noexcept {
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return packed.first().end();
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}
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/**
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* @brief Checks whether a container is empty.
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* @return True if the container is empty, false otherwise.
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*/
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[[nodiscard]] bool empty() const noexcept {
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return packed.first().empty();
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}
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/**
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* @brief Returns the number of elements in a container.
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* @return Number of elements in a container.
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*/
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[[nodiscard]] size_type size() const noexcept {
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return packed.first().size();
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}
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/**
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* @brief Returns the maximum possible number of elements.
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* @return Maximum possible number of elements.
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*/
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[[nodiscard]] size_type max_size() const noexcept {
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return packed.first().max_size();
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}
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/*! @brief Clears the container. */
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void clear() noexcept {
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sparse.first().clear();
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packed.first().clear();
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rehash(0u);
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}
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/**
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* @brief Inserts an element into the container, if it does not exist.
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* @param value An element to insert into the container.
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* @return A pair consisting of an iterator to the inserted element (or to
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* the element that prevented the insertion) and a bool denoting whether the
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* insertion took place.
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*/
|
|
std::pair<iterator, bool> insert(const value_type &value) {
|
|
return insert_or_do_nothing(value);
|
|
}
|
|
|
|
/*! @copydoc insert */
|
|
std::pair<iterator, bool> insert(value_type &&value) {
|
|
return insert_or_do_nothing(std::move(value));
|
|
}
|
|
|
|
/**
|
|
* @brief Inserts elements into the container, if they do not exist.
|
|
* @tparam It Type of input iterator.
|
|
* @param first An iterator to the first element of the range of elements.
|
|
* @param last An iterator past the last element of the range of elements.
|
|
*/
|
|
template<typename It>
|
|
void insert(It first, It last) {
|
|
for(; first != last; ++first) {
|
|
insert(*first);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @brief Constructs an element in-place, if it does not exist.
|
|
*
|
|
* The element is also constructed when the container already has the key,
|
|
* in which case the newly constructed object is destroyed immediately.
|
|
*
|
|
* @tparam Args Types of arguments to forward to the constructor of the
|
|
* element.
|
|
* @param args Arguments to forward to the constructor of the element.
|
|
* @return A pair consisting of an iterator to the inserted element (or to
|
|
* the element that prevented the insertion) and a bool denoting whether the
|
|
* insertion took place.
|
|
*/
|
|
template<typename... Args>
|
|
std::pair<iterator, bool> emplace(Args &&...args) {
|
|
if constexpr(((sizeof...(Args) == 1u) && ... && std::is_same_v<std::decay_t<Args>, value_type>)) {
|
|
return insert_or_do_nothing(std::forward<Args>(args)...);
|
|
} else {
|
|
auto &node = packed.first().emplace_back(std::piecewise_construct, std::make_tuple(packed.first().size()), std::forward_as_tuple(std::forward<Args>(args)...));
|
|
const auto index = value_to_bucket(node.second);
|
|
|
|
if(auto it = constrained_find(node.second, index); it != end()) {
|
|
packed.first().pop_back();
|
|
return std::make_pair(it, false);
|
|
}
|
|
|
|
std::swap(node.first, sparse.first()[index]);
|
|
rehash_if_required();
|
|
|
|
return std::make_pair(--end(), true);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @brief Removes an element from a given position.
|
|
* @param pos An iterator to the element to remove.
|
|
* @return An iterator following the removed element.
|
|
*/
|
|
iterator erase(const_iterator pos) {
|
|
const auto diff = pos - cbegin();
|
|
erase(*pos);
|
|
return begin() + diff;
|
|
}
|
|
|
|
/**
|
|
* @brief Removes the given elements from a container.
|
|
* @param first An iterator to the first element of the range of elements.
|
|
* @param last An iterator past the last element of the range of elements.
|
|
* @return An iterator following the last removed element.
|
|
*/
|
|
iterator erase(const_iterator first, const_iterator last) {
|
|
const auto dist = first - cbegin();
|
|
|
|
for(auto from = last - cbegin(); from != dist; --from) {
|
|
erase(packed.first()[from - 1u].second);
|
|
}
|
|
|
|
return (begin() + dist);
|
|
}
|
|
|
|
/**
|
|
* @brief Removes the element associated with a given value.
|
|
* @param value Value of an element to remove.
|
|
* @return Number of elements removed (either 0 or 1).
|
|
*/
|
|
size_type erase(const value_type &value) {
|
|
for(size_type *curr = sparse.first().data() + value_to_bucket(value); *curr != (std::numeric_limits<size_type>::max)(); curr = &packed.first()[*curr].first) {
|
|
if(packed.second()(packed.first()[*curr].second, value)) {
|
|
const auto index = *curr;
|
|
*curr = packed.first()[*curr].first;
|
|
move_and_pop(index);
|
|
return 1u;
|
|
}
|
|
}
|
|
|
|
return 0u;
|
|
}
|
|
|
|
/**
|
|
* @brief Exchanges the contents with those of a given container.
|
|
* @param other Container to exchange the content with.
|
|
*/
|
|
void swap(dense_set &other) {
|
|
using std::swap;
|
|
swap(sparse, other.sparse);
|
|
swap(packed, other.packed);
|
|
swap(threshold, other.threshold);
|
|
}
|
|
|
|
/**
|
|
* @brief Returns the number of elements matching a value (either 1 or 0).
|
|
* @param key Key value of an element to search for.
|
|
* @return Number of elements matching the key (either 1 or 0).
|
|
*/
|
|
[[nodiscard]] size_type count(const value_type &key) const {
|
|
return find(key) != end();
|
|
}
|
|
|
|
/**
|
|
* @brief Returns the number of elements matching a key (either 1 or 0).
|
|
* @tparam Other Type of the key value of an element to search for.
|
|
* @param key Key value of an element to search for.
|
|
* @return Number of elements matching the key (either 1 or 0).
|
|
*/
|
|
template<typename Other>
|
|
[[nodiscard]] std::enable_if_t<is_transparent_v<hasher> && is_transparent_v<key_equal>, std::conditional_t<false, Other, size_type>>
|
|
count(const Other &key) const {
|
|
return find(key) != end();
|
|
}
|
|
|
|
/**
|
|
* @brief Finds an element with a given value.
|
|
* @param value Value of an element to search for.
|
|
* @return An iterator to an element with the given value. If no such
|
|
* element is found, a past-the-end iterator is returned.
|
|
*/
|
|
[[nodiscard]] iterator find(const value_type &value) {
|
|
return constrained_find(value, value_to_bucket(value));
|
|
}
|
|
|
|
/*! @copydoc find */
|
|
[[nodiscard]] const_iterator find(const value_type &value) const {
|
|
return constrained_find(value, value_to_bucket(value));
|
|
}
|
|
|
|
/**
|
|
* @brief Finds an element that compares _equivalent_ to a given value.
|
|
* @tparam Other Type of an element to search for.
|
|
* @param value Value of an element to search for.
|
|
* @return An iterator to an element with the given value. If no such
|
|
* element is found, a past-the-end iterator is returned.
|
|
*/
|
|
template<typename Other>
|
|
[[nodiscard]] std::enable_if_t<is_transparent_v<hasher> && is_transparent_v<key_equal>, std::conditional_t<false, Other, iterator>>
|
|
find(const Other &value) {
|
|
return constrained_find(value, value_to_bucket(value));
|
|
}
|
|
|
|
/*! @copydoc find */
|
|
template<typename Other>
|
|
[[nodiscard]] std::enable_if_t<is_transparent_v<hasher> && is_transparent_v<key_equal>, std::conditional_t<false, Other, const_iterator>>
|
|
find(const Other &value) const {
|
|
return constrained_find(value, value_to_bucket(value));
|
|
}
|
|
|
|
/**
|
|
* @brief Returns a range containing all elements with a given value.
|
|
* @param value Value of an element to search for.
|
|
* @return A pair of iterators pointing to the first element and past the
|
|
* last element of the range.
|
|
*/
|
|
[[nodiscard]] std::pair<iterator, iterator> equal_range(const value_type &value) {
|
|
const auto it = find(value);
|
|
return {it, it + !(it == end())};
|
|
}
|
|
|
|
/*! @copydoc equal_range */
|
|
[[nodiscard]] std::pair<const_iterator, const_iterator> equal_range(const value_type &value) const {
|
|
const auto it = find(value);
|
|
return {it, it + !(it == cend())};
|
|
}
|
|
|
|
/**
|
|
* @brief Returns a range containing all elements that compare _equivalent_
|
|
* to a given value.
|
|
* @tparam Other Type of an element to search for.
|
|
* @param value Value of an element to search for.
|
|
* @return A pair of iterators pointing to the first element and past the
|
|
* last element of the range.
|
|
*/
|
|
template<typename Other>
|
|
[[nodiscard]] std::enable_if_t<is_transparent_v<hasher> && is_transparent_v<key_equal>, std::conditional_t<false, Other, std::pair<iterator, iterator>>>
|
|
equal_range(const Other &value) {
|
|
const auto it = find(value);
|
|
return {it, it + !(it == end())};
|
|
}
|
|
|
|
/*! @copydoc equal_range */
|
|
template<class Other>
|
|
[[nodiscard]] std::enable_if_t<is_transparent_v<hasher> && is_transparent_v<key_equal>, std::conditional_t<false, Other, std::pair<const_iterator, const_iterator>>>
|
|
equal_range(const Other &value) const {
|
|
const auto it = find(value);
|
|
return {it, it + !(it == cend())};
|
|
}
|
|
|
|
/**
|
|
* @brief Checks if the container contains an element with a given value.
|
|
* @param value Value of an element to search for.
|
|
* @return True if there is such an element, false otherwise.
|
|
*/
|
|
[[nodiscard]] bool contains(const value_type &value) const {
|
|
return (find(value) != cend());
|
|
}
|
|
|
|
/**
|
|
* @brief Checks if the container contains an element that compares
|
|
* _equivalent_ to a given value.
|
|
* @tparam Other Type of an element to search for.
|
|
* @param value Value of an element to search for.
|
|
* @return True if there is such an element, false otherwise.
|
|
*/
|
|
template<typename Other>
|
|
[[nodiscard]] std::enable_if_t<is_transparent_v<hasher> && is_transparent_v<key_equal>, std::conditional_t<false, Other, bool>>
|
|
contains(const Other &value) const {
|
|
return (find(value) != cend());
|
|
}
|
|
|
|
/**
|
|
* @brief Returns an iterator to the beginning of a given bucket.
|
|
* @param index An index of a bucket to access.
|
|
* @return An iterator to the beginning of the given bucket.
|
|
*/
|
|
[[nodiscard]] const_local_iterator cbegin(const size_type index) const {
|
|
return {packed.first().begin(), sparse.first()[index]};
|
|
}
|
|
|
|
/**
|
|
* @brief Returns an iterator to the beginning of a given bucket.
|
|
* @param index An index of a bucket to access.
|
|
* @return An iterator to the beginning of the given bucket.
|
|
*/
|
|
[[nodiscard]] const_local_iterator begin(const size_type index) const {
|
|
return cbegin(index);
|
|
}
|
|
|
|
/**
|
|
* @brief Returns an iterator to the beginning of a given bucket.
|
|
* @param index An index of a bucket to access.
|
|
* @return An iterator to the beginning of the given bucket.
|
|
*/
|
|
[[nodiscard]] local_iterator begin(const size_type index) {
|
|
return {packed.first().begin(), sparse.first()[index]};
|
|
}
|
|
|
|
/**
|
|
* @brief Returns an iterator to the end of a given bucket.
|
|
* @param index An index of a bucket to access.
|
|
* @return An iterator to the end of the given bucket.
|
|
*/
|
|
[[nodiscard]] const_local_iterator cend([[maybe_unused]] const size_type index) const {
|
|
return {packed.first().begin(), (std::numeric_limits<size_type>::max)()};
|
|
}
|
|
|
|
/**
|
|
* @brief Returns an iterator to the end of a given bucket.
|
|
* @param index An index of a bucket to access.
|
|
* @return An iterator to the end of the given bucket.
|
|
*/
|
|
[[nodiscard]] const_local_iterator end(const size_type index) const {
|
|
return cend(index);
|
|
}
|
|
|
|
/**
|
|
* @brief Returns an iterator to the end of a given bucket.
|
|
* @param index An index of a bucket to access.
|
|
* @return An iterator to the end of the given bucket.
|
|
*/
|
|
[[nodiscard]] local_iterator end([[maybe_unused]] const size_type index) {
|
|
return {packed.first().begin(), (std::numeric_limits<size_type>::max)()};
|
|
}
|
|
|
|
/**
|
|
* @brief Returns the number of buckets.
|
|
* @return The number of buckets.
|
|
*/
|
|
[[nodiscard]] size_type bucket_count() const {
|
|
return sparse.first().size();
|
|
}
|
|
|
|
/**
|
|
* @brief Returns the maximum number of buckets.
|
|
* @return The maximum number of buckets.
|
|
*/
|
|
[[nodiscard]] size_type max_bucket_count() const {
|
|
return sparse.first().max_size();
|
|
}
|
|
|
|
/**
|
|
* @brief Returns the number of elements in a given bucket.
|
|
* @param index The index of the bucket to examine.
|
|
* @return The number of elements in the given bucket.
|
|
*/
|
|
[[nodiscard]] size_type bucket_size(const size_type index) const {
|
|
return static_cast<size_type>(std::distance(begin(index), end(index)));
|
|
}
|
|
|
|
/**
|
|
* @brief Returns the bucket for a given element.
|
|
* @param value The value of the element to examine.
|
|
* @return The bucket for the given element.
|
|
*/
|
|
[[nodiscard]] size_type bucket(const value_type &value) const {
|
|
return value_to_bucket(value);
|
|
}
|
|
|
|
/**
|
|
* @brief Returns the average number of elements per bucket.
|
|
* @return The average number of elements per bucket.
|
|
*/
|
|
[[nodiscard]] float load_factor() const {
|
|
return size() / static_cast<float>(bucket_count());
|
|
}
|
|
|
|
/**
|
|
* @brief Returns the maximum average number of elements per bucket.
|
|
* @return The maximum average number of elements per bucket.
|
|
*/
|
|
[[nodiscard]] float max_load_factor() const {
|
|
return threshold;
|
|
}
|
|
|
|
/**
|
|
* @brief Sets the desired maximum average number of elements per bucket.
|
|
* @param value A desired maximum average number of elements per bucket.
|
|
*/
|
|
void max_load_factor(const float value) {
|
|
ENTT_ASSERT(value > 0.f, "Invalid load factor");
|
|
threshold = value;
|
|
rehash(0u);
|
|
}
|
|
|
|
/**
|
|
* @brief Reserves at least the specified number of buckets and regenerates
|
|
* the hash table.
|
|
* @param cnt New number of buckets.
|
|
*/
|
|
void rehash(const size_type cnt) {
|
|
auto value = cnt > minimum_capacity ? cnt : minimum_capacity;
|
|
const auto cap = static_cast<size_type>(size() / max_load_factor());
|
|
value = value > cap ? value : cap;
|
|
|
|
if(const auto sz = next_power_of_two(value); sz != bucket_count()) {
|
|
sparse.first().resize(sz);
|
|
|
|
for(auto &&elem: sparse.first()) {
|
|
elem = std::numeric_limits<size_type>::max();
|
|
}
|
|
|
|
for(size_type pos{}, last = size(); pos < last; ++pos) {
|
|
const auto index = value_to_bucket(packed.first()[pos].second);
|
|
packed.first()[pos].first = std::exchange(sparse.first()[index], pos);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @brief Reserves space for at least the specified number of elements and
|
|
* regenerates the hash table.
|
|
* @param cnt New number of elements.
|
|
*/
|
|
void reserve(const size_type cnt) {
|
|
packed.first().reserve(cnt);
|
|
rehash(static_cast<size_type>(std::ceil(cnt / max_load_factor())));
|
|
}
|
|
|
|
/**
|
|
* @brief Returns the function used to hash the elements.
|
|
* @return The function used to hash the elements.
|
|
*/
|
|
[[nodiscard]] hasher hash_function() const {
|
|
return sparse.second();
|
|
}
|
|
|
|
/**
|
|
* @brief Returns the function used to compare elements for equality.
|
|
* @return The function used to compare elements for equality.
|
|
*/
|
|
[[nodiscard]] key_equal key_eq() const {
|
|
return packed.second();
|
|
}
|
|
|
|
private:
|
|
compressed_pair<sparse_container_type, hasher> sparse;
|
|
compressed_pair<packed_container_type, key_equal> packed;
|
|
float threshold;
|
|
};
|
|
|
|
} // namespace entt
|
|
|
|
#endif
|