forked from boostorg/unordered
		
	Was breaking for allocators that don't have good enough support for void_pointer. Which I suspect is pretty common. [SVN r74800]
		
			
				
	
	
		
			668 lines
		
	
	
		
			20 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			668 lines
		
	
	
		
			20 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
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// Copyright (C) 2003-2004 Jeremy B. Maitin-Shepard.
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// Copyright (C) 2005-2011 Daniel James
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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#ifndef BOOST_UNORDERED_DETAIL_MANAGER_HPP_INCLUDED
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#define BOOST_UNORDERED_DETAIL_MANAGER_HPP_INCLUDED
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#if defined(_MSC_VER) && (_MSC_VER >= 1020)
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# pragma once
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#endif
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#include <boost/unordered/detail/util.hpp>
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#include <boost/unordered/detail/allocator_helpers.hpp>
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#include <boost/unordered/detail/emplace_args.hpp>
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#include <boost/type_traits/aligned_storage.hpp>
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#include <boost/type_traits/alignment_of.hpp>
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#include <boost/swap.hpp>
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#include <boost/assert.hpp>
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#if defined(BOOST_MSVC)
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#pragma warning(push)
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#pragma warning(disable:4127) // conditional expression is constant
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#endif
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namespace boost { namespace unordered { namespace detail {
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    template <typename Types> struct table;
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    template <typename NodePointer> struct bucket;
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    struct ptr_bucket;
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    template <typename A, typename Bucket, typename Node> struct buckets;
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    ///////////////////////////////////////////////////////////////////
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    //
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    // Node construction
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    template <typename NodeAlloc>
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    struct node_constructor
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    {
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    private:
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        typedef NodeAlloc node_allocator;
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        typedef boost::unordered::detail::allocator_traits<NodeAlloc>
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            node_allocator_traits;
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        typedef typename node_allocator_traits::value_type node;
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        typedef typename node_allocator_traits::pointer node_pointer;
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        typedef typename node::value_type value_type;
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        node_allocator& alloc_;
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        node_pointer node_;
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        bool node_constructed_;
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        bool value_constructed_;
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    public:
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        node_constructor(node_allocator& n) :
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            alloc_(n),
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            node_(),
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            node_constructed_(false),
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            value_constructed_(false)
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        {
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        }
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        ~node_constructor();
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        void construct_node();
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        template <BOOST_UNORDERED_EMPLACE_TEMPLATE>
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        void construct_value(BOOST_UNORDERED_EMPLACE_ARGS)
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        {
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            BOOST_ASSERT(node_ && node_constructed_ && !value_constructed_);
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            boost::unordered::detail::construct_impl(
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                node_->value_ptr(), BOOST_UNORDERED_EMPLACE_FORWARD);
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            value_constructed_ = true;
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        }
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        template <typename A0>
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        void construct_value2(BOOST_FWD_REF(A0) a0)
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        {
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            BOOST_ASSERT(node_ && node_constructed_ && !value_constructed_);
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            boost::unordered::detail::construct_impl2(
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                node_->value_ptr(), boost::forward<A0>(a0));
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            value_constructed_ = true;
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        }
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        value_type const& value() const {
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            BOOST_ASSERT(node_ && node_constructed_ && value_constructed_);
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            return node_->value();
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        }
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        // no throw
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        node_pointer release()
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        {
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            node_pointer p = node_;
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            node_ = node_pointer();
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            return p;
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        }
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    private:
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        node_constructor(node_constructor const&);
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        node_constructor& operator=(node_constructor const&);
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    };
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    template <typename Alloc>
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    node_constructor<Alloc>::~node_constructor()
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    {
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        if (node_) {
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            if (value_constructed_) {
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                boost::unordered::detail::destroy(node_->value_ptr());
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            }
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            if (node_constructed_) {
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                node_allocator_traits::destroy(alloc_,
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                    boost::addressof(*node_));
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            }
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            node_allocator_traits::deallocate(alloc_, node_, 1);
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        }
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    }
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    template <typename Alloc>
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    void node_constructor<Alloc>::construct_node()
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    {
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        if(!node_) {
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            node_constructed_ = false;
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            value_constructed_ = false;
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            node_ = node_allocator_traits::allocate(alloc_, 1);
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            node_allocator_traits::construct(alloc_,
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                boost::addressof(*node_), node());
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            node_->init(static_cast<typename node::link_pointer>(node_));
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            node_constructed_ = true;
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        }
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        else {
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            BOOST_ASSERT(node_constructed_);
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            if (value_constructed_)
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            {
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                boost::unordered::detail::destroy(node_->value_ptr());
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                value_constructed_ = false;
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            }
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        }
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    }
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    ///////////////////////////////////////////////////////////////////
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    //
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    // Bucket
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    template <typename NodePointer>
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    struct bucket
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    {
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        typedef NodePointer previous_pointer;
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        previous_pointer next_;
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        bucket() : next_() {}
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        previous_pointer first_from_start()
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        {
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            return next_;
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        }
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        enum { extra_node = true };
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    };
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    struct ptr_bucket
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    {
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        typedef ptr_bucket* previous_pointer;
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        previous_pointer next_;
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        ptr_bucket() : next_(0) {}
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        previous_pointer first_from_start()
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        {
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            return this;
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        }
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        enum { extra_node = false };
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    };
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    ///////////////////////////////////////////////////////////////////
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    //
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    // Buckets
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    template <typename A, typename Bucket, typename Node>
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    struct buckets
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    {
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    private:
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        buckets(buckets const&);
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        buckets& operator=(buckets const&);
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    public:
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        typedef boost::unordered::detail::allocator_traits<A> traits;
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        typedef typename traits::value_type value_type;
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        typedef Node node;
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        typedef Bucket bucket;
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        typedef typename boost::unordered::detail::rebind_wrap<A, node>::type
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            node_allocator;
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        typedef typename boost::unordered::detail::rebind_wrap<A, bucket>::type
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            bucket_allocator;
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        typedef boost::unordered::detail::allocator_traits<node_allocator>
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            node_allocator_traits;
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        typedef boost::unordered::detail::allocator_traits<bucket_allocator>
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            bucket_allocator_traits;
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        typedef typename node_allocator_traits::pointer
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            node_pointer;
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        typedef typename node_allocator_traits::const_pointer
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            const_node_pointer;
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        typedef typename bucket_allocator_traits::pointer
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            bucket_pointer;
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        typedef typename bucket::previous_pointer
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            previous_pointer;
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        typedef boost::unordered::detail::node_constructor<node_allocator>
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            node_constructor;
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        // Members
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        bucket_pointer buckets_;
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        std::size_t bucket_count_;
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        std::size_t size_;
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        boost::unordered::detail::compressed<bucket_allocator, node_allocator>
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            allocators_;
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        // Data access
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        bucket_allocator const& bucket_alloc() const
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        {
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            return allocators_.first();
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        }
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        node_allocator const& node_alloc() const
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        {
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            return allocators_.second();
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        }
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        bucket_allocator& bucket_alloc()
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        {
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            return allocators_.first();
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        }
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        node_allocator& node_alloc()
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        {
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            return allocators_.second();
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        }
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        std::size_t max_bucket_count() const
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        {
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            // -1 to account for the start bucket.
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            return boost::unordered::detail::prev_prime(
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                bucket_allocator_traits::max_size(bucket_alloc()) - 1);
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        }
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        bucket_pointer get_bucket(std::size_t bucket_index) const
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        {
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            return buckets_ + static_cast<std::ptrdiff_t>(bucket_index);
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        }
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        previous_pointer get_previous_start() const
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        {
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            return this->get_bucket(this->bucket_count_)->first_from_start();
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        }
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        previous_pointer get_previous_start(std::size_t bucket_index) const
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        {
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            return this->get_bucket(bucket_index)->next_;
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        }
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        node_pointer get_start() const
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        {
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            return static_cast<node_pointer>(this->get_previous_start()->next_);
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        }
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        node_pointer get_start(std::size_t bucket_index) const
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        {
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            previous_pointer prev = this->get_previous_start(bucket_index);
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            return prev ? static_cast<node_pointer>(prev->next_) :
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                node_pointer();
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        }
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        float load_factor() const
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        {
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            BOOST_ASSERT(this->bucket_count_ != 0);
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            return static_cast<float>(this->size_)
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                / static_cast<float>(this->bucket_count_);
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        }
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        std::size_t bucket_size(std::size_t index) const
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        {
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            if (!this->size_) return 0;
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            node_pointer ptr = this->get_start(index);
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            if (!ptr) return 0;
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            std::size_t count = 0;
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            while(ptr && ptr->hash_ % this->bucket_count_ == index)
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            {
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                ++count;
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                ptr = static_cast<node_pointer>(ptr->next_);
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            }
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            return count;
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        }
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        ////////////////////////////////////////////////////////////////////////
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        // Constructors
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        buckets(node_allocator const& a, std::size_t bucket_count) :
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            buckets_(),
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            bucket_count_(bucket_count),
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            size_(),
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            allocators_(a,a)
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        {
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        }
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        buckets(buckets& b, boost::unordered::detail::move_tag m) :
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            buckets_(),
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            bucket_count_(b.bucket_count_),
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            size_(),
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            allocators_(b.allocators_, m)
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        {
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            swap(b);
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        }
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        template <typename Types>
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        buckets(boost::unordered::detail::table<Types>& x,
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                boost::unordered::detail::move_tag m) :
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            buckets_(),
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            bucket_count_(x.bucket_count_),
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            size_(),
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            allocators_(x.allocators_, m)
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        {
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            swap(x);
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        }
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        ////////////////////////////////////////////////////////////////////////
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        // Create buckets
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        // (never called in constructor to avoid exception issues)
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        void create_buckets()
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        {
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            boost::unordered::detail::array_constructor<bucket_allocator>
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                constructor(bucket_alloc());
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            // Creates an extra bucket to act as the start node.
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            constructor.construct(bucket(), this->bucket_count_ + 1);
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            if (bucket::extra_node)
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            {
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                node_constructor a(this->node_alloc());
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                a.construct_node();
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                (constructor.get() +
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                    static_cast<std::ptrdiff_t>(this->bucket_count_))->next_ =
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                        a.release();
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            }
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            this->buckets_ = constructor.release();
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        }
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        ////////////////////////////////////////////////////////////////////////
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        // Swap and Move
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        void swap(buckets& other, false_type = false_type())
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        {
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            BOOST_ASSERT(node_alloc() == other.node_alloc());
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            boost::swap(buckets_, other.buckets_);
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            boost::swap(bucket_count_, other.bucket_count_);
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            boost::swap(size_, other.size_);
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        }
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        void swap(buckets& other, true_type)
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        {
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            allocators_.swap(other.allocators_);
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            boost::swap(buckets_, other.buckets_);
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            boost::swap(bucket_count_, other.bucket_count_);
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            boost::swap(size_, other.size_);
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        }
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        void move_buckets_from(buckets& other)
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        {
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            BOOST_ASSERT(node_alloc() == other.node_alloc());
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            BOOST_ASSERT(!this->buckets_);
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            this->buckets_ = other.buckets_;
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            this->bucket_count_ = other.bucket_count_;
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            this->size_ = other.size_;
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            other.buckets_ = bucket_pointer();
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            other.bucket_count_ = 0;
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            other.size_ = 0;
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        }
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        ////////////////////////////////////////////////////////////////////////
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        // Delete/destruct
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        inline void delete_node(node_pointer n)
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        {
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            boost::unordered::detail::destroy(n->value_ptr());
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            node_allocator_traits::destroy(node_alloc(), boost::addressof(*n));
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            node_allocator_traits::deallocate(node_alloc(), n, 1);
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            --size_;
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        }
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        std::size_t delete_nodes(node_pointer begin, node_pointer end)
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        {
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            std::size_t count = 0;
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            while(begin != end) {
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                node_pointer n = begin;
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                begin = static_cast<node_pointer>(begin->next_);
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                delete_node(n);
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                ++count;
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            }
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            return count;
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        }
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        inline void delete_extra_node(bucket_pointer) {}
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        inline void delete_extra_node(node_pointer n) {
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            node_allocator_traits::destroy(node_alloc(), boost::addressof(*n));
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            node_allocator_traits::deallocate(node_alloc(), n, 1);
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        }
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        inline ~buckets()
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        {
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            this->delete_buckets();
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        }
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        void delete_buckets()
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        {
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            if(this->buckets_) {
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                previous_pointer prev = this->get_previous_start();
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                while(prev->next_) {
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                    node_pointer n = static_cast<node_pointer>(prev->next_);
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                    prev->next_ = n->next_;
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                    delete_node(n);
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                }
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                delete_extra_node(prev);
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                bucket_pointer end = this->get_bucket(this->bucket_count_ + 1);
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                for(bucket_pointer it = this->buckets_; it != end; ++it)
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                {
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                    bucket_allocator_traits::destroy(bucket_alloc(),
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                        boost::addressof(*it));
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                }
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                bucket_allocator_traits::deallocate(bucket_alloc(),
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                    this->buckets_, this->bucket_count_ + 1);
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                this->buckets_ = bucket_pointer();
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            }
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            BOOST_ASSERT(!this->size_);
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        }
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        void clear()
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        {
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            if(!this->size_) return;
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            previous_pointer prev = this->get_previous_start();
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            while(prev->next_) {
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                node_pointer n = static_cast<node_pointer>(prev->next_);
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                prev->next_ = n->next_;
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                delete_node(n);
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            }
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            bucket_pointer end = this->get_bucket(this->bucket_count_);
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            for(bucket_pointer it = this->buckets_; it != end; ++it)
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            {
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                it->next_ = node_pointer();
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            }
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            BOOST_ASSERT(!this->size_);
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        }
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        // This is called after erasing a node or group of nodes to fix up
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        // the bucket pointers.
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        void fix_buckets(bucket_pointer bucket,
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                previous_pointer prev, node_pointer next)
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        {
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            if (!next)
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            {
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                if (bucket->next_ == prev) bucket->next_ = node_pointer();
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            }
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            else
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            {
 | 
						|
                bucket_pointer next_bucket = this->get_bucket(
 | 
						|
                    next->hash_ % this->bucket_count_);
 | 
						|
 | 
						|
                if (next_bucket != bucket)
 | 
						|
                {
 | 
						|
                    next_bucket->next_ = prev;
 | 
						|
                    if (bucket->next_ == prev) bucket->next_ = node_pointer();
 | 
						|
                }
 | 
						|
            }
 | 
						|
        }
 | 
						|
 | 
						|
        // This is called after erasing a range of nodes to fix any bucket
 | 
						|
        // pointers into that range.
 | 
						|
        void fix_buckets_range(std::size_t bucket_index,
 | 
						|
                previous_pointer prev, node_pointer begin, node_pointer end)
 | 
						|
        {
 | 
						|
            node_pointer n = begin;
 | 
						|
    
 | 
						|
            // If we're not at the start of the current bucket, then
 | 
						|
            // go to the start of the next bucket.
 | 
						|
            if (this->get_bucket(bucket_index)->next_ != prev)
 | 
						|
            {
 | 
						|
                for(;;) {
 | 
						|
                    n = static_cast<node_pointer>(n->next_);
 | 
						|
                    if (n == end) return;
 | 
						|
    
 | 
						|
                    std::size_t new_bucket_index =
 | 
						|
                        n->hash_ % this->bucket_count_;
 | 
						|
                    if (bucket_index != new_bucket_index) {
 | 
						|
                        bucket_index = new_bucket_index;
 | 
						|
                        break;
 | 
						|
                    }
 | 
						|
                }
 | 
						|
            }
 | 
						|
    
 | 
						|
            // Iterate through the remaining nodes, clearing out the bucket
 | 
						|
            // pointers.
 | 
						|
            this->get_bucket(bucket_index)->next_ = previous_pointer();
 | 
						|
            for(;;) {
 | 
						|
                n = static_cast<node_pointer>(n->next_);
 | 
						|
                if (n == end) break;
 | 
						|
    
 | 
						|
                std::size_t new_bucket_index =
 | 
						|
                    n->hash_ % this->bucket_count_;
 | 
						|
                if (bucket_index != new_bucket_index) {
 | 
						|
                    bucket_index = new_bucket_index;
 | 
						|
                    this->get_bucket(bucket_index)->next_ = previous_pointer();
 | 
						|
                }
 | 
						|
            };
 | 
						|
    
 | 
						|
            // Finally fix the bucket containing the trailing node.
 | 
						|
            if (n) {
 | 
						|
                this->get_bucket(n->hash_ % this->bucket_count_)->next_
 | 
						|
                    = prev;
 | 
						|
            }
 | 
						|
        }
 | 
						|
    };
 | 
						|
 | 
						|
    ////////////////////////////////////////////////////////////////////////////
 | 
						|
    // Functions
 | 
						|
 | 
						|
    // Assigning and swapping the equality and hash function objects
 | 
						|
    // needs strong exception safety. To implement that normally we'd
 | 
						|
    // require one of them to be known to not throw and the other to
 | 
						|
    // guarantee strong exception safety. Unfortunately they both only
 | 
						|
    // have basic exception safety. So to acheive strong exception
 | 
						|
    // safety we have storage space for two copies, and assign the new
 | 
						|
    // copies to the unused space. Then switch to using that to use
 | 
						|
    // them. This is implemented in 'set_hash_functions' which
 | 
						|
    // atomically assigns the new function objects in a strongly
 | 
						|
    // exception safe manner.
 | 
						|
 | 
						|
    template <class H, class P> class set_hash_functions;
 | 
						|
 | 
						|
    template <class H, class P>
 | 
						|
    class functions
 | 
						|
    {
 | 
						|
        friend class boost::unordered::detail::set_hash_functions<H, P>;
 | 
						|
        functions& operator=(functions const&);
 | 
						|
 | 
						|
        typedef compressed<H, P> function_pair;
 | 
						|
 | 
						|
        typedef typename boost::aligned_storage<
 | 
						|
            sizeof(function_pair),
 | 
						|
            boost::alignment_of<function_pair>::value>::type aligned_function;
 | 
						|
 | 
						|
        bool current_; // The currently active functions.
 | 
						|
        aligned_function funcs_[2];
 | 
						|
 | 
						|
        function_pair const& current() const {
 | 
						|
            return *static_cast<function_pair const*>(
 | 
						|
                static_cast<void const*>(&funcs_[current_]));
 | 
						|
        }
 | 
						|
 | 
						|
        void construct(bool which, H const& hf, P const& eq)
 | 
						|
        {
 | 
						|
            new((void*) &funcs_[which]) function_pair(hf, eq);
 | 
						|
        }
 | 
						|
 | 
						|
        void construct(bool which, function_pair const& f)
 | 
						|
        {
 | 
						|
            new((void*) &funcs_[which]) function_pair(f);
 | 
						|
        }
 | 
						|
        
 | 
						|
        void destroy(bool which)
 | 
						|
        {
 | 
						|
            boost::unordered::detail::destroy((function_pair*)(&funcs_[which]));
 | 
						|
        }
 | 
						|
        
 | 
						|
    public:
 | 
						|
 | 
						|
        functions(H const& hf, P const& eq)
 | 
						|
            : current_(false)
 | 
						|
        {
 | 
						|
            construct(current_, hf, eq);
 | 
						|
        }
 | 
						|
 | 
						|
        functions(functions const& bf)
 | 
						|
            : current_(false)
 | 
						|
        {
 | 
						|
            construct(current_, bf.current());
 | 
						|
        }
 | 
						|
 | 
						|
        ~functions() {
 | 
						|
            this->destroy(current_);
 | 
						|
        }
 | 
						|
 | 
						|
        H const& hash_function() const {
 | 
						|
            return current().first();
 | 
						|
        }
 | 
						|
 | 
						|
        P const& key_eq() const {
 | 
						|
            return current().second();
 | 
						|
        }
 | 
						|
    };
 | 
						|
    
 | 
						|
    template <class H, class P>
 | 
						|
    class set_hash_functions
 | 
						|
    {
 | 
						|
        set_hash_functions(set_hash_functions const&);
 | 
						|
        set_hash_functions& operator=(set_hash_functions const&);
 | 
						|
    
 | 
						|
        functions<H,P>& functions_;
 | 
						|
        bool tmp_functions_;
 | 
						|
 | 
						|
    public:
 | 
						|
 | 
						|
        set_hash_functions(functions<H,P>& f, H const& h, P const& p)
 | 
						|
          : functions_(f),
 | 
						|
            tmp_functions_(!f.current_)
 | 
						|
        {
 | 
						|
            f.construct(tmp_functions_, h, p);
 | 
						|
        }
 | 
						|
 | 
						|
        set_hash_functions(functions<H,P>& f, functions<H,P> const& other)
 | 
						|
          : functions_(f),
 | 
						|
            tmp_functions_(!f.current_)
 | 
						|
        {
 | 
						|
            f.construct(tmp_functions_, other.current());
 | 
						|
        }
 | 
						|
 | 
						|
        ~set_hash_functions()
 | 
						|
        {
 | 
						|
            functions_.destroy(tmp_functions_);
 | 
						|
        }
 | 
						|
 | 
						|
        void commit()
 | 
						|
        {
 | 
						|
            functions_.current_ = tmp_functions_;
 | 
						|
            tmp_functions_ = !tmp_functions_;
 | 
						|
        }
 | 
						|
    };
 | 
						|
}}}
 | 
						|
 | 
						|
#if defined(BOOST_MSVC)
 | 
						|
#pragma warning(pop)
 | 
						|
#endif
 | 
						|
 | 
						|
#endif
 |