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499 lines
17 KiB
C++
499 lines
17 KiB
C++
// Helper classes and functions for the circular buffer.
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// Copyright (c) 2003-2008 Jan Gaspar
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// Copyright (c) 2014 Glen Fernandes // C++11 allocator model support.
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// Use, modification, and distribution is subject to the Boost Software
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// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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#if !defined(BOOST_CIRCULAR_BUFFER_DETAILS_HPP)
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#define BOOST_CIRCULAR_BUFFER_DETAILS_HPP
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#if defined(_MSC_VER)
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#pragma once
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#endif
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#include <boost/throw_exception.hpp>
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#include <boost/container/allocator_traits.hpp>
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#include <boost/move/move.hpp>
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#include <boost/type_traits/is_nothrow_move_constructible.hpp>
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#include <boost/utility/addressof.hpp>
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#include <boost/detail/no_exceptions_support.hpp>
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#include <iterator>
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// Silence MS /W4 warnings like C4913:
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// "user defined binary operator ',' exists but no overload could convert all operands, default built-in binary operator ',' used"
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// This might happen when previously including some boost headers that overload the coma operator.
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#if defined(_MSC_VER)
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# pragma warning(push)
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# pragma warning(disable:4913)
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#endif
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namespace boost {
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namespace cb_details {
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template <class Traits> struct nonconst_traits;
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template<class ForwardIterator, class Diff, class T, class Alloc>
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void uninitialized_fill_n_with_alloc(
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ForwardIterator first, Diff n, const T& item, Alloc& alloc);
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template<class InputIterator, class ForwardIterator, class Alloc>
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ForwardIterator uninitialized_copy(InputIterator first, InputIterator last, ForwardIterator dest, Alloc& a);
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template<class InputIterator, class ForwardIterator, class Alloc>
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ForwardIterator uninitialized_move_if_noexcept(InputIterator first, InputIterator last, ForwardIterator dest, Alloc& a);
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/*!
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\struct const_traits
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\brief Defines the data types for a const iterator.
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*/
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template <class Traits>
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struct const_traits {
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// Basic types
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typedef typename Traits::value_type value_type;
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typedef typename Traits::const_pointer pointer;
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typedef typename Traits::const_reference reference;
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typedef typename Traits::size_type size_type;
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typedef typename Traits::difference_type difference_type;
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// Non-const traits
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typedef nonconst_traits<Traits> nonconst_self;
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};
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/*!
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\struct nonconst_traits
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\brief Defines the data types for a non-const iterator.
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*/
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template <class Traits>
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struct nonconst_traits {
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// Basic types
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typedef typename Traits::value_type value_type;
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typedef typename Traits::pointer pointer;
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typedef typename Traits::reference reference;
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typedef typename Traits::size_type size_type;
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typedef typename Traits::difference_type difference_type;
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// Non-const traits
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typedef nonconst_traits<Traits> nonconst_self;
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};
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/*!
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\struct iterator_wrapper
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\brief Helper iterator dereference wrapper.
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*/
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template <class Iterator>
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struct iterator_wrapper {
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mutable Iterator m_it;
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explicit iterator_wrapper(Iterator it) : m_it(it) {}
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Iterator operator () () const { return m_it++; }
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private:
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iterator_wrapper<Iterator>& operator = (const iterator_wrapper<Iterator>&); // do not generate
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};
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/*!
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\struct item_wrapper
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\brief Helper item dereference wrapper.
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*/
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template <class Pointer, class Value>
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struct item_wrapper {
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Value m_item;
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explicit item_wrapper(Value item) : m_item(item) {}
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Pointer operator () () const { return &m_item; }
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private:
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item_wrapper<Pointer, Value>& operator = (const item_wrapper<Pointer, Value>&); // do not generate
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};
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/*!
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\struct assign_n
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\brief Helper functor for assigning n items.
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*/
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template <class Value, class Alloc>
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struct assign_n {
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typedef typename boost::container::allocator_traits<Alloc>::size_type size_type;
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size_type m_n;
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Value m_item;
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Alloc& m_alloc;
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assign_n(size_type n, Value item, Alloc& alloc) : m_n(n), m_item(item), m_alloc(alloc) {}
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template <class Pointer>
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void operator () (Pointer p) const {
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uninitialized_fill_n_with_alloc(p, m_n, m_item, m_alloc);
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}
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private:
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assign_n<Value, Alloc>& operator = (const assign_n<Value, Alloc>&); // do not generate
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};
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/*!
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\struct assign_range
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\brief Helper functor for assigning range of items.
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*/
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template <class Iterator, class Alloc>
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struct assign_range {
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Iterator m_first;
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Iterator m_last;
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Alloc& m_alloc;
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assign_range(const Iterator& first, const Iterator& last, Alloc& alloc)
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: m_first(first), m_last(last), m_alloc(alloc) {}
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template <class Pointer>
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void operator () (Pointer p) const {
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boost::cb_details::uninitialized_copy(m_first, m_last, p, m_alloc);
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}
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};
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template <class Iterator, class Alloc>
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inline assign_range<Iterator, Alloc> make_assign_range(const Iterator& first, const Iterator& last, Alloc& a) {
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return assign_range<Iterator, Alloc>(first, last, a);
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}
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/*!
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\class capacity_control
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\brief Capacity controller of the space optimized circular buffer.
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*/
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template <class Size>
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class capacity_control {
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//! The capacity of the space-optimized circular buffer.
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Size m_capacity;
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//! The lowest guaranteed or minimum capacity of the adapted space-optimized circular buffer.
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Size m_min_capacity;
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public:
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//! Constructor.
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capacity_control(Size buffer_capacity, Size min_buffer_capacity = 0)
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: m_capacity(buffer_capacity), m_min_capacity(min_buffer_capacity)
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{ // Check for capacity lower than min_capacity.
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BOOST_CB_ASSERT(buffer_capacity >= min_buffer_capacity);
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}
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// Default copy constructor.
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// Default assign operator.
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//! Get the capacity of the space optimized circular buffer.
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Size capacity() const { return m_capacity; }
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//! Get the minimal capacity of the space optimized circular buffer.
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Size min_capacity() const { return m_min_capacity; }
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//! Size operator - returns the capacity of the space optimized circular buffer.
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operator Size() const { return m_capacity; }
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};
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/*!
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\struct iterator
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\brief Random access iterator for the circular buffer.
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\param Buff The type of the underlying circular buffer.
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\param Traits Basic iterator types.
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\note This iterator is not circular. It was designed
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for iterating from begin() to end() of the circular buffer.
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*/
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template <class Buff, class Traits>
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struct iterator :
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public std::iterator<
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std::random_access_iterator_tag,
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typename Traits::value_type,
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typename Traits::difference_type,
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typename Traits::pointer,
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typename Traits::reference>
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#if BOOST_CB_ENABLE_DEBUG
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, public debug_iterator_base
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#endif // #if BOOST_CB_ENABLE_DEBUG
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{
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// Helper types
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//! Base iterator.
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typedef std::iterator<
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std::random_access_iterator_tag,
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typename Traits::value_type,
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typename Traits::difference_type,
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typename Traits::pointer,
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typename Traits::reference> base_iterator;
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//! Non-const iterator.
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typedef iterator<Buff, typename Traits::nonconst_self> nonconst_self;
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// Basic types
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//! The type of the elements stored in the circular buffer.
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typedef typename base_iterator::value_type value_type;
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//! Pointer to the element.
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typedef typename base_iterator::pointer pointer;
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//! Reference to the element.
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typedef typename base_iterator::reference reference;
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//! Size type.
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typedef typename Traits::size_type size_type;
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//! Difference type.
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typedef typename base_iterator::difference_type difference_type;
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// Member variables
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//! The circular buffer where the iterator points to.
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const Buff* m_buff;
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//! An internal iterator.
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pointer m_it;
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// Construction & assignment
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// Default copy constructor.
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//! Default constructor.
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iterator() : m_buff(0), m_it(0) {}
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#if BOOST_CB_ENABLE_DEBUG
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//! Copy constructor (used for converting from a non-const to a const iterator).
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iterator(const nonconst_self& it) : debug_iterator_base(it), m_buff(it.m_buff), m_it(it.m_it) {}
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//! Internal constructor.
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/*!
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\note This constructor is not intended to be used directly by the user.
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*/
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iterator(const Buff* cb, const pointer p) : debug_iterator_base(cb), m_buff(cb), m_it(p) {}
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#else
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iterator(const nonconst_self& it) : m_buff(it.m_buff), m_it(it.m_it) {}
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iterator(const Buff* cb, const pointer p) : m_buff(cb), m_it(p) {}
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#endif // #if BOOST_CB_ENABLE_DEBUG
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//! Assign operator.
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iterator& operator = (const iterator& it) {
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if (this == &it)
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return *this;
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#if BOOST_CB_ENABLE_DEBUG
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debug_iterator_base::operator =(it);
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#endif // #if BOOST_CB_ENABLE_DEBUG
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m_buff = it.m_buff;
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m_it = it.m_it;
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return *this;
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}
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// Random access iterator methods
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//! Dereferencing operator.
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reference operator * () const {
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BOOST_CB_ASSERT(is_valid(m_buff)); // check for uninitialized or invalidated iterator
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BOOST_CB_ASSERT(m_it != 0); // check for iterator pointing to end()
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return *m_it;
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}
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//! Dereferencing operator.
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pointer operator -> () const { return &(operator*()); }
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//! Difference operator.
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template <class Traits0>
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difference_type operator - (const iterator<Buff, Traits0>& it) const {
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BOOST_CB_ASSERT(is_valid(m_buff)); // check for uninitialized or invalidated iterator
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BOOST_CB_ASSERT(it.is_valid(m_buff)); // check for uninitialized or invalidated iterator
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return linearize_pointer(*this) - linearize_pointer(it);
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}
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//! Increment operator (prefix).
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iterator& operator ++ () {
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BOOST_CB_ASSERT(is_valid(m_buff)); // check for uninitialized or invalidated iterator
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BOOST_CB_ASSERT(m_it != 0); // check for iterator pointing to end()
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m_buff->increment(m_it);
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if (m_it == m_buff->m_last)
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m_it = 0;
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return *this;
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}
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//! Increment operator (postfix).
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iterator operator ++ (int) {
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iterator<Buff, Traits> tmp = *this;
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++*this;
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return tmp;
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}
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//! Decrement operator (prefix).
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iterator& operator -- () {
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BOOST_CB_ASSERT(is_valid(m_buff)); // check for uninitialized or invalidated iterator
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BOOST_CB_ASSERT(m_it != m_buff->m_first); // check for iterator pointing to begin()
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if (m_it == 0)
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m_it = m_buff->m_last;
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m_buff->decrement(m_it);
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return *this;
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}
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//! Decrement operator (postfix).
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iterator operator -- (int) {
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iterator<Buff, Traits> tmp = *this;
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--*this;
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return tmp;
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}
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//! Iterator addition.
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iterator& operator += (difference_type n) {
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BOOST_CB_ASSERT(is_valid(m_buff)); // check for uninitialized or invalidated iterator
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if (n > 0) {
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BOOST_CB_ASSERT(m_buff->end() - *this >= n); // check for too large n
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m_it = m_buff->add(m_it, n);
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if (m_it == m_buff->m_last)
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m_it = 0;
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} else if (n < 0) {
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*this -= -n;
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}
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return *this;
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}
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//! Iterator addition.
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iterator operator + (difference_type n) const { return iterator<Buff, Traits>(*this) += n; }
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//! Iterator subtraction.
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iterator& operator -= (difference_type n) {
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BOOST_CB_ASSERT(is_valid(m_buff)); // check for uninitialized or invalidated iterator
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if (n > 0) {
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BOOST_CB_ASSERT(*this - m_buff->begin() >= n); // check for too large n
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m_it = m_buff->sub(m_it == 0 ? m_buff->m_last : m_it, n);
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} else if (n < 0) {
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*this += -n;
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}
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return *this;
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}
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//! Iterator subtraction.
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iterator operator - (difference_type n) const { return iterator<Buff, Traits>(*this) -= n; }
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//! Element access operator.
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reference operator [] (difference_type n) const { return *(*this + n); }
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// Equality & comparison
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//! Equality.
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template <class Traits0>
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bool operator == (const iterator<Buff, Traits0>& it) const {
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BOOST_CB_ASSERT(is_valid(m_buff)); // check for uninitialized or invalidated iterator
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BOOST_CB_ASSERT(it.is_valid(m_buff)); // check for uninitialized or invalidated iterator
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return m_it == it.m_it;
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}
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//! Inequality.
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template <class Traits0>
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bool operator != (const iterator<Buff, Traits0>& it) const {
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BOOST_CB_ASSERT(is_valid(m_buff)); // check for uninitialized or invalidated iterator
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BOOST_CB_ASSERT(it.is_valid(m_buff)); // check for uninitialized or invalidated iterator
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return m_it != it.m_it;
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}
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//! Less.
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template <class Traits0>
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bool operator < (const iterator<Buff, Traits0>& it) const {
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BOOST_CB_ASSERT(is_valid(m_buff)); // check for uninitialized or invalidated iterator
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BOOST_CB_ASSERT(it.is_valid(m_buff)); // check for uninitialized or invalidated iterator
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return linearize_pointer(*this) < linearize_pointer(it);
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}
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//! Greater.
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template <class Traits0>
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bool operator > (const iterator<Buff, Traits0>& it) const { return it < *this; }
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//! Less or equal.
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template <class Traits0>
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bool operator <= (const iterator<Buff, Traits0>& it) const { return !(it < *this); }
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//! Greater or equal.
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template <class Traits0>
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bool operator >= (const iterator<Buff, Traits0>& it) const { return !(*this < it); }
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// Helpers
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//! Get a pointer which would point to the same element as the iterator in case the circular buffer is linearized.
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template <class Traits0>
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typename Traits0::pointer linearize_pointer(const iterator<Buff, Traits0>& it) const {
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return it.m_it == 0 ? m_buff->m_buff + m_buff->size() :
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(it.m_it < m_buff->m_first ? it.m_it + (m_buff->m_end - m_buff->m_first)
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: m_buff->m_buff + (it.m_it - m_buff->m_first));
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}
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};
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//! Iterator addition.
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template <class Buff, class Traits>
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inline iterator<Buff, Traits>
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operator + (typename Traits::difference_type n, const iterator<Buff, Traits>& it) {
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return it + n;
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}
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/*!
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\fn ForwardIterator uninitialized_copy(InputIterator first, InputIterator last, ForwardIterator dest)
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\brief Equivalent of <code>std::uninitialized_copy</code> but with explicit specification of value type.
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*/
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template<class InputIterator, class ForwardIterator, class Alloc>
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inline ForwardIterator uninitialized_copy(InputIterator first, InputIterator last, ForwardIterator dest, Alloc& a) {
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ForwardIterator next = dest;
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BOOST_TRY {
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for (; first != last; ++first, ++dest)
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boost::container::allocator_traits<Alloc>::construct(a, boost::addressof(*dest), *first);
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} BOOST_CATCH(...) {
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for (; next != dest; ++next)
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boost::container::allocator_traits<Alloc>::destroy(a, boost::addressof(*next));
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BOOST_RETHROW
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}
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BOOST_CATCH_END
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return dest;
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}
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template<class InputIterator, class ForwardIterator, class Alloc>
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ForwardIterator uninitialized_move_if_noexcept_impl(InputIterator first, InputIterator last, ForwardIterator dest, Alloc& a,
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true_type) {
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for (; first != last; ++first, ++dest)
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boost::container::allocator_traits<Alloc>::construct(a, boost::addressof(*dest), boost::move(*first));
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return dest;
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}
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template<class InputIterator, class ForwardIterator, class Alloc>
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ForwardIterator uninitialized_move_if_noexcept_impl(InputIterator first, InputIterator last, ForwardIterator dest, Alloc& a,
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false_type) {
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return uninitialized_copy(first, last, dest, a);
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}
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/*!
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\fn ForwardIterator uninitialized_move_if_noexcept(InputIterator first, InputIterator last, ForwardIterator dest)
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\brief Equivalent of <code>std::uninitialized_copy</code> but with explicit specification of value type and moves elements if they have noexcept move constructors.
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*/
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template<class InputIterator, class ForwardIterator, class Alloc>
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ForwardIterator uninitialized_move_if_noexcept(InputIterator first, InputIterator last, ForwardIterator dest, Alloc& a) {
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typedef typename boost::is_nothrow_move_constructible<typename boost::container::allocator_traits<Alloc>::value_type>::type tag_t;
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return uninitialized_move_if_noexcept_impl(first, last, dest, a, tag_t());
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}
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/*!
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\fn void uninitialized_fill_n_with_alloc(ForwardIterator first, Diff n, const T& item, Alloc& alloc)
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\brief Equivalent of <code>std::uninitialized_fill_n</code> with allocator.
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*/
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template<class ForwardIterator, class Diff, class T, class Alloc>
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inline void uninitialized_fill_n_with_alloc(ForwardIterator first, Diff n, const T& item, Alloc& alloc) {
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ForwardIterator next = first;
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BOOST_TRY {
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for (; n > 0; ++first, --n)
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boost::container::allocator_traits<Alloc>::construct(alloc, boost::addressof(*first), item);
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} BOOST_CATCH(...) {
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for (; next != first; ++next)
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boost::container::allocator_traits<Alloc>::destroy(alloc, boost::addressof(*next));
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BOOST_RETHROW
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}
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BOOST_CATCH_END
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}
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} // namespace cb_details
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} // namespace boost
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#if defined(_MSC_VER)
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# pragma warning(pop)
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#endif
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#endif // #if !defined(BOOST_CIRCULAR_BUFFER_DETAILS_HPP)
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