hopscotch_set.h

#ifndef TSL_HOPSCOTCH_SET_H
#define TSL_HOPSCOTCH_SET_H


#include <algorithm>
#include <cstddef>
#include <functional>
#include <initializer_list>
#include <list>
#include <memory>
#include <type_traits>
#include <utility>
#include "hopscotch_hash.h"


namespace tsl {

template<class Key, 
         class Hash = std::hash<Key>,
         class KeyEqual = std::equal_to<Key>,
         class Allocator = std::allocator<Key>,
         unsigned int NeighborhoodSize = 62,
         bool StoreHash = false,
         class GrowthPolicy = tsl::power_of_two_growth_policy>
class hopscotch_set {
private:    
    template<typename U>
    using has_is_transparent = tsl::detail_hopscotch_hash::has_is_transparent<U>;
    
    class KeySelect {
    public:
        using key_type = Key;
        
        const key_type& operator()(const Key& key) const {
            return key;
        }
        
        key_type& operator()(Key& key) {
            return key;
        }
    };
    
    
    using overflow_container_type = std::list<Key, Allocator>;
    using ht = detail_hopscotch_hash::hopscotch_hash<Key, KeySelect, void,
                                                     Hash, KeyEqual, 
                                                     Allocator, NeighborhoodSize, 
                                                     StoreHash, GrowthPolicy,
                                                     overflow_container_type>;
            
public:
    using key_type = typename ht::key_type;
    using value_type = typename ht::value_type;
    using size_type = typename ht::size_type;
    using difference_type = typename ht::difference_type;
    using hasher = typename ht::hasher;
    using key_equal = typename ht::key_equal;
    using allocator_type = typename ht::allocator_type;
    using reference = typename ht::reference;
    using const_reference = typename ht::const_reference;
    using pointer = typename ht::pointer;
    using const_pointer = typename ht::const_pointer;
    using iterator = typename ht::iterator;
    using const_iterator = typename ht::const_iterator;

    
    /*
     * Constructors
     */
    hopscotch_set() : hopscotch_set(ht::DEFAULT_INIT_BUCKETS_SIZE) {
    }
    
    explicit hopscotch_set(size_type bucket_count, 
                        const Hash& hash = Hash(),
                        const KeyEqual& equal = KeyEqual(),
                        const Allocator& alloc = Allocator()) : 
                        m_ht(bucket_count, hash, equal, alloc, ht::DEFAULT_MAX_LOAD_FACTOR)
    {
    }
    
    hopscotch_set(size_type bucket_count,
                  const Allocator& alloc) : hopscotch_set(bucket_count, Hash(), KeyEqual(), alloc)
    {
    }
    
    hopscotch_set(size_type bucket_count,
                  const Hash& hash,
                  const Allocator& alloc) : hopscotch_set(bucket_count, hash, KeyEqual(), alloc)
    {
    }
    
    explicit hopscotch_set(const Allocator& alloc) : hopscotch_set(ht::DEFAULT_INIT_BUCKETS_SIZE, alloc) {
    }
    
    template<class InputIt>
    hopscotch_set(InputIt first, InputIt last,
                size_type bucket_count = ht::DEFAULT_INIT_BUCKETS_SIZE,
                const Hash& hash = Hash(),
                const KeyEqual& equal = KeyEqual(),
                const Allocator& alloc = Allocator()) : hopscotch_set(bucket_count, hash, equal, alloc)
    {
        insert(first, last);
    }
    
    template<class InputIt>
    hopscotch_set(InputIt first, InputIt last,
                size_type bucket_count,
                const Allocator& alloc) : hopscotch_set(first, last, bucket_count, Hash(), KeyEqual(), alloc)
    {
    }
    
    template<class InputIt>
    hopscotch_set(InputIt first, InputIt last,
                size_type bucket_count,
                const Hash& hash,
                const Allocator& alloc) : hopscotch_set(first, last, bucket_count, hash, KeyEqual(), alloc)
    {
    }

    hopscotch_set(std::initializer_list<value_type> init,
                    size_type bucket_count = ht::DEFAULT_INIT_BUCKETS_SIZE,
                    const Hash& hash = Hash(),
                    const KeyEqual& equal = KeyEqual(),
                    const Allocator& alloc = Allocator()) : 
                    hopscotch_set(init.begin(), init.end(), bucket_count, hash, equal, alloc)
    {
    }

    hopscotch_set(std::initializer_list<value_type> init,
                    size_type bucket_count,
                    const Allocator& alloc) : 
                    hopscotch_set(init.begin(), init.end(), bucket_count, Hash(), KeyEqual(), alloc)
    {
    }

    hopscotch_set(std::initializer_list<value_type> init,
                    size_type bucket_count,
                    const Hash& hash,
                    const Allocator& alloc) : 
                    hopscotch_set(init.begin(), init.end(), bucket_count, hash, KeyEqual(), alloc)
    {
    }

    
    hopscotch_set& operator=(std::initializer_list<value_type> ilist) {
        m_ht.clear();
        
        m_ht.reserve(ilist.size());
        m_ht.insert(ilist.begin(), ilist.end());
        
        return *this;
    }
    
    allocator_type get_allocator() const { return m_ht.get_allocator(); }
    
    
    /*
     * Iterators
     */
    iterator begin() noexcept { return m_ht.begin(); }
    const_iterator begin() const noexcept { return m_ht.begin(); }
    const_iterator cbegin() const noexcept { return m_ht.cbegin(); }
    
    iterator end() noexcept { return m_ht.end(); }
    const_iterator end() const noexcept { return m_ht.end(); }
    const_iterator cend() const noexcept { return m_ht.cend(); }
    
    
    /*
     * Capacity
     */
    bool empty() const noexcept { return m_ht.empty(); }
    size_type size() const noexcept { return m_ht.size(); }
    size_type max_size() const noexcept { return m_ht.max_size(); }
    
    /*
     * Modifiers
     */
    void clear() noexcept { m_ht.clear(); }
    
    
    
    
    std::pair<iterator, bool> insert(const value_type& value) { return m_ht.insert(value); }
    std::pair<iterator, bool> insert(value_type&& value) { return m_ht.insert(std::move(value)); }
    
    iterator insert(const_iterator hint, const value_type& value) { return m_ht.insert(hint, value); }
    iterator insert(const_iterator hint, value_type&& value) { return m_ht.insert(hint, std::move(value)); }
    
    template<class InputIt>
    void insert(InputIt first, InputIt last) { m_ht.insert(first, last); }
    void insert(std::initializer_list<value_type> ilist) { m_ht.insert(ilist.begin(), ilist.end()); }

    
    
    
    template<class... Args>
    std::pair<iterator, bool> emplace(Args&&... args) { return m_ht.emplace(std::forward<Args>(args)...); }
    
    
    
    
    template<class... Args>
    iterator emplace_hint(const_iterator hint, Args&&... args) {
        return m_ht.emplace_hint(hint, std::forward<Args>(args)...);
    }

    
    
    
    iterator erase(iterator pos) { return m_ht.erase(pos); }
    iterator erase(const_iterator pos) { return m_ht.erase(pos); }
    iterator erase(const_iterator first, const_iterator last) { return m_ht.erase(first, last); }
    size_type erase(const key_type& key) { return m_ht.erase(key); }
    
    size_type erase(const key_type& key, std::size_t precalculated_hash) { 
        return m_ht.erase(key, precalculated_hash); 
    }
    
    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
    size_type erase(const K& key) { return m_ht.erase(key); }
    
    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
    size_type erase(const K& key, std::size_t precalculated_hash) { 
        return m_ht.erase(key, precalculated_hash); 
    }
    
    
    
    
    void swap(hopscotch_set& other) { other.m_ht.swap(m_ht); }
    
    
    /*
     * Lookup
     */
    size_type count(const Key& key) const { return m_ht.count(key); }
    
    size_type count(const Key& key, std::size_t precalculated_hash) const { return m_ht.count(key, precalculated_hash); }
    
    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
    size_type count(const K& key) const { return m_ht.count(key); }
    
    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
    size_type count(const K& key, std::size_t precalculated_hash) const { return m_ht.count(key, precalculated_hash); }
    
    
    
    
    iterator find(const Key& key) { return m_ht.find(key); }
    
    iterator find(const Key& key, std::size_t precalculated_hash) { return m_ht.find(key, precalculated_hash); }
    
    const_iterator find(const Key& key) const { return m_ht.find(key); }
    
    const_iterator find(const Key& key, std::size_t precalculated_hash) const { return m_ht.find(key, precalculated_hash); }
    
    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
    iterator find(const K& key) { return m_ht.find(key); }
    
    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
    iterator find(const K& key, std::size_t precalculated_hash) { return m_ht.find(key, precalculated_hash); }
    
    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
    const_iterator find(const K& key) const { return m_ht.find(key); }
    
    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
    const_iterator find(const K& key, std::size_t precalculated_hash) const { return m_ht.find(key, precalculated_hash); }
    
    
    
    
    std::pair<iterator, iterator> equal_range(const Key& key) { return m_ht.equal_range(key); }
    
    std::pair<iterator, iterator> equal_range(const Key& key, std::size_t precalculated_hash) { 
        return m_ht.equal_range(key, precalculated_hash); 
    }
    
    std::pair<const_iterator, const_iterator> equal_range(const Key& key) const { return m_ht.equal_range(key); }
    
    std::pair<const_iterator, const_iterator> equal_range(const Key& key, std::size_t precalculated_hash) const { 
        return m_ht.equal_range(key, precalculated_hash); 
    }
    
    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
    std::pair<iterator, iterator> equal_range(const K& key) { return m_ht.equal_range(key); }
    
    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
    std::pair<iterator, iterator> equal_range(const K& key, std::size_t precalculated_hash) { 
        return m_ht.equal_range(key, precalculated_hash); 
    }
    
    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
    std::pair<const_iterator, const_iterator> equal_range(const K& key) const { return m_ht.equal_range(key); }

    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
    std::pair<const_iterator, const_iterator> equal_range(const K& key, std::size_t precalculated_hash) const { 
        return m_ht.equal_range(key, precalculated_hash); 
    }
    
    
    

    /*
     * Bucket interface 
     */
    size_type bucket_count() const { return m_ht.bucket_count(); }
    size_type max_bucket_count() const { return m_ht.max_bucket_count(); }
    
    
    /*
     *  Hash policy 
     */
    float load_factor() const { return m_ht.load_factor(); }
    float max_load_factor() const { return m_ht.max_load_factor(); }
    void max_load_factor(float ml) { m_ht.max_load_factor(ml); }
    
    void rehash(size_type count) { m_ht.rehash(count); }
    void reserve(size_type count) { m_ht.reserve(count); }
    
    
    /*
     * Observers
     */
    hasher hash_function() const { return m_ht.hash_function(); }
    key_equal key_eq() const { return m_ht.key_eq(); }
    
    
    /*
     * Other
     */
    
    iterator mutable_iterator(const_iterator pos) {
        return m_ht.mutable_iterator(pos);
    }
    
    size_type overflow_size() const noexcept { return m_ht.overflow_size(); }
    
    friend bool operator==(const hopscotch_set& lhs, const hopscotch_set& rhs) {
        if(lhs.size() != rhs.size()) {
            return false;
        }
        
        for(const auto& element_lhs : lhs) {
            const auto it_element_rhs = rhs.find(element_lhs);
            if(it_element_rhs == rhs.cend()) {
                return false;
            }
        }
        
        return true;
    }

    friend bool operator!=(const hopscotch_set& lhs, const hopscotch_set& rhs) {
        return !operator==(lhs, rhs);
    }

    friend void swap(hopscotch_set& lhs, hopscotch_set& rhs) {
        lhs.swap(rhs);
    }
    
private:
    ht m_ht;    
};

} // end namespace tsl

#endif