// SPDX-License-Identifier: BSD-3-Clause
/* Copyright 2018-2021, Intel Corporation */

/**
 * @file
 * Vector container with std::vector compatible interface.
 */

#ifndef LIBPMEMOBJ_CPP_VECTOR_HPP
#define LIBPMEMOBJ_CPP_VECTOR_HPP

#include <libpmemobj++/container/detail/contiguous_iterator.hpp>
#include <libpmemobj++/detail/common.hpp>
#include <libpmemobj++/detail/iterator_traits.hpp>
#include <libpmemobj++/detail/life.hpp>
#include <libpmemobj++/detail/temp_value.hpp>
#include <libpmemobj++/make_persistent.hpp>
#include <libpmemobj++/persistent_ptr.hpp>
#include <libpmemobj++/pext.hpp>
#include <libpmemobj++/slice.hpp>
#include <libpmemobj++/transaction.hpp>
#include <libpmemobj++/utils.hpp>
#include <libpmemobj/base.h>

#include <algorithm>
#include <cassert>
#include <utility>
#include <vector>

namespace pmem
{

namespace obj
{

/**
 * Persistent container with std::vector compatible interface.
 * @ingroup containers
 */
template <typename T>
class vector {
public:
	/* Member types */
	using value_type = T;
	using size_type = std::size_t;
	using difference_type = std::ptrdiff_t;
	using reference = value_type &;
	using const_reference = const value_type &;
	using pointer = value_type *;
	using const_pointer = const value_type *;
	using iterator = pmem::detail::basic_contiguous_iterator<T>;
	using const_iterator = const_pointer;
	using reverse_iterator = std::reverse_iterator<iterator>;
	using const_reverse_iterator = std::reverse_iterator<const_iterator>;
	using range_snapshotting_iterator =
		pmem::detail::range_snapshotting_iterator<T>;
	/* func argument type definition for 'for_each_ptr' method */
	using for_each_ptr_function =
		std::function<void(persistent_ptr_base &)>;

	/* Constructors */
	vector();
	vector(size_type count, const value_type &value);
	explicit vector(size_type count);
	template <typename InputIt,
		  typename std::enable_if<
			  detail::is_input_iterator<InputIt>::value,
			  InputIt>::type * = nullptr>
	vector(InputIt first, InputIt last);
	vector(const vector &other);
	vector(vector &&other);
	vector(std::initializer_list<T> init);
	vector(const std::vector<T> &other);

	/* Assign operators */
	vector &operator=(const vector &other);
	vector &operator=(vector &&other);
	vector &operator=(std::initializer_list<T> ilist);
	vector &operator=(const std::vector<T> &other);

	/* Assign methods */
	void assign(size_type count, const T &value);
	template <typename InputIt,
		  typename std::enable_if<
			  detail::is_input_iterator<InputIt>::value,
			  InputIt>::type * = nullptr>
	void assign(InputIt first, InputIt last);
	void assign(std::initializer_list<T> ilist);
	void assign(const vector &other);
	void assign(vector &&other);
	void assign(const std::vector<T> &other);

	/* Destructor */
	~vector();

	/* Element access */
	reference at(size_type n);
	const_reference at(size_type n) const;
	const_reference const_at(size_type n) const;
	reference operator[](size_type n);
	const_reference operator[](size_type n) const;
	reference front();
	const_reference front() const;
	const_reference cfront() const;
	reference back();
	const_reference back() const;
	const_reference cback() const;
	value_type *data();
	const value_type *data() const noexcept;
	const value_type *cdata() const noexcept;

	/* Iterators */
	iterator begin();
	const_iterator begin() const noexcept;
	const_iterator cbegin() const noexcept;
	iterator end();
	const_iterator end() const noexcept;
	const_iterator cend() const noexcept;
	reverse_iterator rbegin();
	const_reverse_iterator rbegin() const noexcept;
	const_reverse_iterator crbegin() const noexcept;
	reverse_iterator rend();
	const_reverse_iterator rend() const noexcept;
	const_reverse_iterator crend() const noexcept;

	/* Range */
	slice<pointer> range(size_type start, size_type n);
	slice<range_snapshotting_iterator> range(size_type start, size_type n,
						 size_type snapshot_size);
	slice<const_iterator> range(size_type start, size_type n) const;
	slice<const_iterator> crange(size_type start, size_type n) const;
	void for_each_ptr(for_each_ptr_function func);

	/* Capacity */
	constexpr bool empty() const noexcept;
	size_type size() const noexcept;
	constexpr size_type max_size() const noexcept;
	void reserve(size_type capacity_new);
	size_type capacity() const noexcept;
	void shrink_to_fit();

	/* Modifiers */
	void clear();
	void free_data();
	iterator insert(const_iterator pos, const T &value);
	iterator insert(const_iterator pos, T &&value);
	iterator insert(const_iterator pos, size_type count, const T &value);
	template <typename InputIt,
		  typename std::enable_if<
			  detail::is_input_iterator<InputIt>::value,
			  InputIt>::type * = nullptr>
	iterator insert(const_iterator pos, InputIt first, InputIt last);
	iterator insert(const_iterator pos, std::initializer_list<T> ilist);
	template <class... Args>
	iterator emplace(const_iterator pos, Args &&... args);
	template <class... Args>
	reference emplace_back(Args &&... args);
	iterator erase(const_iterator pos);
	iterator erase(const_iterator first, const_iterator last);
	void push_back(const T &value);
	void push_back(T &&value);
	void pop_back();
	void resize(size_type count);
	void resize(size_type count, const value_type &value);
	void swap(vector &other);

private:
	/* helper iterator */
	template <typename P>
	struct single_element_iterator {
		using iterator_category = std::input_iterator_tag;
		using value_type = P;
		using difference_type = std::ptrdiff_t;
		using pointer = const P *;
		using reference = const P &;

		const P *ptr;
		std::size_t count;

		single_element_iterator(const P *ptr, std::size_t count = 0)
		    : ptr(ptr), count(count)
		{
		}

		reference operator*()
		{
			return *ptr;
		}

		pointer operator->()
		{
			return ptr;
		}

		single_element_iterator &
		operator++()
		{
			count++;
			return *this;
		}

		single_element_iterator
		operator++(int)
		{
			single_element_iterator tmp =
				single_element_iterator(ptr, count);
			count++;
			return tmp;
		}

		difference_type
		operator-(const single_element_iterator &rhs)
		{
			return count - rhs.count;
		}

		bool
		operator!=(const single_element_iterator &rhs)
		{
			return ptr != rhs.ptr || count != rhs.count;
		}
	};

	/* helper functions */
	void alloc(size_type size);
	void check_pmem();
	void check_tx_stage_work();
	template <typename... Args>
	void construct_at_end(size_type count, Args &&... args);
	template <typename InputIt,
		  typename std::enable_if<
			  detail::is_input_iterator<InputIt>::value,
			  InputIt>::type * = nullptr>
	void construct_at_end(InputIt first, InputIt last);
	void dealloc();
	pool_base get_pool() const;
	template <typename InputIt>
	void internal_insert(size_type idx, InputIt first, InputIt last);
	void realloc(size_type size);
	size_type get_recommended_capacity(size_type at_least) const;
	void shrink(size_type size_new);
	void add_data_to_tx(size_type idx_first, size_type num);
	template <typename InputIt>
	void construct_or_assign(size_type idx, InputIt first, InputIt last);
	void move_elements_backward(pointer first, pointer last,
				    pointer d_last);

	p<size_type> _size;
	p<size_type> _capacity;

	/* Underlying array */
	persistent_ptr<T[]> _data;
};

/* Non-member swap
 * @relates vector
 */
template <typename T>
void swap(vector<T> &lhs, vector<T> &rhs);

/*
 * Comparison operators between pmem::obj::vector<T> and
 * pmem::obj::vector<T>
 */
template <typename T>
bool operator==(const vector<T> &lhs, const vector<T> &rhs);
template <typename T>
bool operator!=(const vector<T> &lhs, const vector<T> &rhs);
template <typename T>
bool operator<(const vector<T> &lhs, const vector<T> &rhs);
template <typename T>
bool operator<=(const vector<T> &lhs, const vector<T> &rhs);
template <typename T>
bool operator>(const vector<T> &lhs, const vector<T> &rhs);
template <typename T>
bool operator>=(const vector<T> &lhs, const vector<T> &rhs);

/*
 * Comparison operators between pmem::obj::vector<T> and
 * std::vector<T>
 */
template <typename T>
bool operator==(const vector<T> &lhs, const std::vector<T> &rhs);
template <typename T>
bool operator!=(const vector<T> &lhs, const std::vector<T> &rhs);
template <typename T>
bool operator<(const vector<T> &lhs, const std::vector<T> &rhs);
template <typename T>
bool operator<=(const vector<T> &lhs, const std::vector<T> &rhs);
template <typename T>
bool operator>(const vector<T> &lhs, const std::vector<T> &rhs);
template <typename T>
bool operator>=(const vector<T> &lhs, const std::vector<T> &rhs);

/*
 * Comparison operators between std::vector<T> and
 * pmem::obj::vector<T>
 */
template <typename T>
bool operator==(const std::vector<T> &lhs, const vector<T> &rhs);
template <typename T>
bool operator!=(const std::vector<T> &lhs, const vector<T> &rhs);
template <typename T>
bool operator<(const std::vector<T> &lhs, const vector<T> &rhs);
template <typename T>
bool operator<=(const std::vector<T> &lhs, const vector<T> &rhs);
template <typename T>
bool operator>(const std::vector<T> &lhs, const vector<T> &rhs);
template <typename T>
bool operator>=(const std::vector<T> &lhs, const vector<T> &rhs);

/**
 * Default constructor. Constructs an empty container.
 *
 * @pre must be called in transaction scope.
 *
 * @throw pmem::pool_error if an object is not in persistent memory.
 * @throw pmem::transaction_scope_error if constructor wasn't called in
 * transaction.
 */
template <typename T>
vector<T>::vector()
{
	check_pmem();
	check_tx_stage_work();

	_data = nullptr;
	_size = 0;
	_capacity = 0;
}

/**
 * Constructs the container with count copies of elements with value value.
 *
 * @param[in] count number of elements to construct.
 * @param[in] value value of all constructed elements.
 *
 * @pre must be called in transaction scope.
 *
 * @post size() == count
 * @post capacity() == size()
 *
 * @throw pmem::pool_error if an object is not in persistent memory.
 * @throw pmem::transaction_alloc_error when allocating memory for underlying
 * array in transaction failed.
 * @throw pmem::transaction_scope_error if constructor wasn't called in
 * transaction.
 * @throw rethrows element constructor exception.
 */
template <typename T>
vector<T>::vector(size_type count, const value_type &value)
{
	check_pmem();
	check_tx_stage_work();

	_data = nullptr;
	_size = 0;
	alloc(count);
	construct_at_end(count, value);
}

/**
 * Constructs the container with count copies of T default constructed values.
 *
 * @param[in] count number of elements to construct.
 *
 * @pre must be called in transaction scope.
 *
 * @post size() == count
 * @post capacity() == size()
 *
 * @throw pmem::pool_error if an object is not in persistent memory.
 * @throw pmem::transaction_alloc_error when allocating memory for underlying
 * array in transaction failed.
 * @throw pmem::transaction_scope_error if constructor wasn't called in
 * transaction.
 * @throw rethrows element constructor exception.
 */
template <typename T>
vector<T>::vector(size_type count)
{
	check_pmem();
	check_tx_stage_work();

	_data = nullptr;
	_size = 0;
	alloc(count);
	construct_at_end(count);
}

/**
 * Constructs the container with the contents of the range [first, last). The
 * first and last arguments must satisfy InputIterator requirements. This
 * overload only participates in overload resolution if InputIt satisfies
 * InputIterator, to avoid ambiguity with the overload of count-value
 * constructor.
 *
 * @param[in] first first iterator.
 * @param[in] last last iterator.
 *
 * @pre must be called in transaction scope.
 *
 * @post size() == std::distance(first, last)
 * @post capacity() == size()
 *
 * @throw pmem::pool_error if an object is not in persistent memory.
 * @throw pmem::transaction_alloc_error when allocating memory for underlying
 * array in transaction failed.
 * @throw pmem::transaction_scope_error if constructor wasn't called in
 * transaction.
 * @throw rethrows element constructor exception.
 */
template <typename T>
template <typename InputIt,
	  typename std::enable_if<detail::is_input_iterator<InputIt>::value,
				  InputIt>::type *>
vector<T>::vector(InputIt first, InputIt last)
{
	check_pmem();
	check_tx_stage_work();

	_data = nullptr;
	_size = 0;
	alloc(static_cast<size_type>(std::distance(first, last)));
	construct_at_end(first, last);
}

/**
 * Copy constructor. Constructs the container with the copy of the
 * contents of other.
 *
 * @param[in] other reference to the vector to be copied.
 *
 * @pre must be called in transaction scope.
 *
 * @post size() == other.size()
 * @post capacity() == other.capacity()
 *
 * @throw pmem::pool_error if an object is not in persistent memory.
 * @throw pmem::transaction_alloc_error when allocating memory for underlying
 * array in transaction failed.
 * @throw pmem::transaction_scope_error if constructor wasn't called in
 * transaction.
 * @throw rethrows element constructor exception.
 */
template <typename T>
vector<T>::vector(const vector &other)
{
	check_pmem();
	check_tx_stage_work();

	_data = nullptr;
	_size = 0;
	alloc(other.capacity());
	construct_at_end(other.cbegin(), other.cend());
}

/**
 * Move constructor. Constructs the container with the contents of other using
 * move semantics. After the move, other is guaranteed to be empty().
 *
 * @param[in] other rvalue reference to the vector to be moved from.
 *
 * @pre must be called in transaction scope.
 *
 * @post size() == other.size()
 * @post capacity() == other.capacity()
 * @post data() == other.data()
 * @post other.data() == nullptr
 * @post other.capacity() == 0
 * @post other.size() == 0
 *
 * @throw pmem::pool_error if an object is not in persistent memory.
 * @throw pmem::transaction_scope_error if constructor wasn't called in
 * transaction.
 */
template <typename T>
vector<T>::vector(vector &&other)
{
	check_pmem();
	check_tx_stage_work();

	_data = other._data;
	_capacity = other.capacity();
	_size = other.size();
	other._data = nullptr;
	other._capacity = other._size = 0;
}

/**
 * Constructs the container with the contents of the initializer list init.
 *
 * @param[in] init initializer list with content to be constructed.
 *
 * @pre must be called in transaction scope.
 *
 * @post size() == init.size()
 * @post capacity() == size()
 *
 * @throw pmem::pool_error if an object is not in persistent memory.
 * @throw pmem::transaction_alloc_error when allocating memory for underlying
 * array in transaction failed.
 * @throw pmem::transaction_scope_error if constructor wasn't called in
 * transaction.
 * @throw rethrows element constructor exception.
 */
template <typename T>
vector<T>::vector(std::initializer_list<T> init)
    : vector(init.begin(), init.end())
{
}

/**
 * Copy constructor. Constructs the container with the copy of the contents of
 * std::vector<T> other. This constructor is not specified by STL standards.
 *
 * @param[in] other reference to the vector to be copied.
 *
 * @pre must be called in transaction scope.
 *
 * @post size() == other.size()
 * @post capacity() == other.capacity()
 *
 * @throw pmem::pool_error if an object is not in persistent memory.
 * @throw pmem::transaction_alloc_error when allocating memory for underlying
 * array in transaction failed.
 * @throw pmem::transaction_scope_error if constructor wasn't called in
 * transaction.
 * @throw rethrows element constructor exception.
 */
template <typename T>
vector<T>::vector(const std::vector<T> &other)
    : vector(other.cbegin(), other.cend())
{
}

/**
 * Copy assignment operator. Replaces the contents with a copy of the contents
 * of other transactionally.
 *
 * @post size() == other.size()
 * @post capacity() == max(size(), other.capacity())
 *
 * @throw pmem::transaction_alloc_error when allocating new memory failed.
 * @throw pmem::transaction_free_error when freeing old underlying array failed.
 * @throw rethrows constructor's exception.
 */
template <typename T>
vector<T> &
vector<T>::operator=(const vector &other)
{
	assign(other);

	return *this;
}

/**
 * Move assignment operator. Replaces the contents with those of other using
 * move semantics (i.e. the data in other is moved from other into this
 * container) transactionally. Other is in a valid but empty state afterwards.
 *
 * @post size() == other.size()
 * @post capacity() == other.capacity()
 *
 * @throw pmem::transaction_free_error when freeing underlying array failed.
 */
template <typename T>
vector<T> &
vector<T>::operator=(vector &&other)
{
	assign(std::move(other));

	return *this;
}

/**
 * Replaces the contents with those identified by initializer list ilist
 * transactionally.
 *
 * @throw std::length_error if ilist.size() > max_size().
 * @throw pmem::transaction_alloc_error when allocating new memory failed.
 * @throw pmem::transaction_free_error when freeing old underlying array failed.
 * @throw rethrows constructor's exception.
 */
template <typename T>
vector<T> &
vector<T>::operator=(std::initializer_list<T> ilist)
{
	assign(ilist.begin(), ilist.end());

	return *this;
}

/**
 * Copy assignment operator. Replaces the contents with a copy of the contents
 * of std::vector<T> other transactionally. This method is not specified by STL
 * standards.
 *
 * @post size() == other.size()
 * @post capacity() == max(size(), other.capacity())
 *
 * @throw pmem::transaction_alloc_error when allocating new memory failed.
 * @throw pmem::transaction_free_error when freeing old underlying array failed.
 * @throw rethrows constructor's exception.
 */
template <typename T>
vector<T> &
vector<T>::operator=(const std::vector<T> &other)
{
	assign(other);

	return *this;
}

/**
 * Replaces the contents with count copies of value value transactionally. All
 * iterators, pointers and references to the elements of the container are
 * invalidated. The past-the-end iterator is also invalidated.
 *
 * @param[in] count number of elements to construct.
 * @param[in] value value of all constructed elements.
 *
 * @post size() == count
 * @post capacity() == max(size(), count)
 *
 * @throw std::length_error if count > max_size().
 * @throw pmem::transaction_alloc_error when allocating new memory failed.
 * @throw pmem::transaction_free_error when freeing old underlying array failed.
 * @throw rethrows constructor's exception.
 */
template <typename T>
void
vector<T>::assign(size_type count, const_reference value)
{
	pool_base pb = get_pool();

	flat_transaction::run(pb, [&] {
		if (count <= capacity()) {
			/*
			 * Reallocation is not needed. First, replace old
			 * elements with new ones in range [0, size()).
			 * Depending on count, either call remaining old
			 * elements destructors, or append more new elements.
			 */
			size_type size_old = _size;
			add_data_to_tx(0, size_old);

			std::fill_n(
				_data.get(),
				(std::min)(count,
					   static_cast<size_type>(size_old)),
				value);

			if (count > size_old) {
				add_data_to_tx(size_old, count - size_old);
				construct_at_end(count - size_old, value);
			} else {
				shrink(count);
			}
		} else {
			dealloc();
			alloc(count);
			construct_at_end(count, value);
		}
	});
}

/**
 * Replaces the contents with copies of those in the range [first, last)
 * transactionally. This overload participates in overload resolution only if
 * InputIt satisfies InputIterator. All iterators, pointers and references to
 * the elements of the container are invalidated. The past-the-end iterator is
 * also invalidated.
 *
 * @param[in] first first iterator.
 * @param[in] last last iterator.
 *
 * @post size() == std::distance(first, last)
 * @post capacity() == max(size(), std::distance(first, last))
 *
 * @throw std::length_error if std::distance(first, last) > max_size().
 * @throw pmem::transaction_alloc_error when allocating new memory failed.
 * @throw pmem::transaction_free_error when freeing old underlying array failed.
 * @throw rethrows constructor's exception.
 */
template <typename T>
template <typename InputIt,
	  typename std::enable_if<detail::is_input_iterator<InputIt>::value,
				  InputIt>::type *>
void
vector<T>::assign(InputIt first, InputIt last)
{
	pool_base pb = get_pool();

	size_type size_new = static_cast<size_type>(std::distance(first, last));

	flat_transaction::run(pb, [&] {
		if (size_new <= capacity()) {
			/*
			 * Reallocation is not needed. First, replace old
			 * elements with new ones in range [0, size()).
			 * Depending on size_new, either call remaining old
			 * elements destructors, or append more new elements.
			 */
			size_type size_old = _size;
			add_data_to_tx(0, size_old);

			InputIt mid = last;
			bool growing = size_new > size_old;

			if (growing) {
				add_data_to_tx(size_old, size_new - size_old);

				mid = first;
				std::advance(mid, size_old);
			}

			iterator shrink_to = std::copy(first, mid, &_data[0]);

			if (growing) {
				construct_at_end(mid, last);
			} else {
				shrink(static_cast<size_type>(std::distance(
					iterator(&_data[0]), shrink_to)));
			}
		} else {
			dealloc();
			alloc(size_new);
			construct_at_end(first, last);
		}
	});
}

/**
 * Replaces the contents with the elements from the initializer list ilist
 * transactionally. All iterators, pointers and references to the elements of
 * the container are invalidated. The past-the-end iterator is also invalidated.
 *
 * @param[in] ilist initializer list with content to be constructed.
 *
 * @post size() == std::distance(ilist.begin(), ilist.end())
 * @post capacity() == max(size(), capacity())
 *
 * @throw std::length_error if std::distance(first, last) > max_size().
 * @throw pmem::transaction_alloc_error when allocating new memory failed.
 * @throw pmem::transaction_free_error when freeing old underlying array failed.
 * @throw rethrows constructor's exception.
 */
template <typename T>
void
vector<T>::assign(std::initializer_list<T> ilist)
{
	assign(ilist.begin(), ilist.end());
}

/**
 * Copy assignment method. Replaces the contents with a copy of the contents
 * of other transactionally. This method is not specified by STL standards.
 *
 * @post size() == other.size()
 * @post capacity() == max(size(), other.capacity())
 *
 * @throw pmem::transaction_alloc_error when allocating new memory failed.
 * @throw pmem::transaction_free_error when freeing old underlying array failed.
 * @throw rethrows constructor's exception.
 */
template <typename T>
void
vector<T>::assign(const vector &other)
{
	if (this != &other)
		assign(other.cbegin(), other.cend());
}

/**
 * Move assignment method. Replaces the contents with those of other using
 * move semantics (i.e. the data in other is moved from other into this
 * container) transactionally. Other is in a valid but empty state afterwards.
 * This method is not specified by STL standards.
 *
 * @post size() == other.size()
 * @post capacity() == other.capacity()
 *
 * @throw pmem::transaction_free_error when freeing underlying array failed.
 */
template <typename T>
void
vector<T>::assign(vector &&other)
{
	if (this == &other)
		return;

	pool_base pb = get_pool();

	flat_transaction::run(pb, [&] {
		dealloc();

		_data = other._data;
		_capacity = other._capacity;
		_size = other._size;

		other._data = nullptr;
		other._capacity = other._size = 0;
	});
}

/**
 * Copy assignment method. Replaces the contents with a copy of the contents
 * of std::vector<T> other transactionally. This method is not specified by STL
 * standards.
 *
 * @post size() == other.size()
 * @post capacity() == max(size(), other.capacity())
 *
 * @throw pmem::transaction_alloc_error when allocating new memory failed.
 * @throw pmem::transaction_free_error when freeing old underlying array failed.
 * @throw rethrows constructor's exception.
 */
template <typename T>
void
vector<T>::assign(const std::vector<T> &other)
{
	assign(other.cbegin(), other.cend());
}

/**
 * Destructor.
 * Note that free_data may throw a transaction_free_error
 * when freeing underlying array failed. It is recommended
 * to call free_data manually before object destruction,
 * otherwise application can be terminated on failure.
 */
template <typename T>
vector<T>::~vector()
{
	try {
		free_data();
	} catch (...) {
		std::terminate();
	}
}

/**
 * Access element at specific index with bounds checking and add it to a
 * transaction.
 *
 * @param[in] n index number.
 *
 * @return reference to element number n in underlying array.
 *
 * @throw std::out_of_range if n is not within the range of the container.
 * @throw pmem::transaction_error when adding the object to the transaction
 * failed.
 */
template <typename T>
typename vector<T>::reference
vector<T>::at(size_type n)
{
	if (n >= _size)
		throw std::out_of_range("vector::at");

	detail::conditional_add_to_tx(&_data[static_cast<difference_type>(n)],
				      1, POBJ_XADD_ASSUME_INITIALIZED);

	return _data[static_cast<difference_type>(n)];
}

/**
 * Access element at specific index with bounds checking.
 *
 * @param[in] n index number.
 *
 * @return const_reference to element number n in underlying array.
 *
 * @throw std::out_of_range if n is not within the range of the container.
 */
template <typename T>
typename vector<T>::const_reference
vector<T>::at(size_type n) const
{
	if (n >= _size)
		throw std::out_of_range("vector::at");

	return _data[static_cast<difference_type>(n)];
}

/**
 * Access element at specific index with bounds checking. In contradiction to
 * at(), const_at() will return const_reference not depending on the
 * const-qualification of the object it is called on. std::vector doesn't
 * provide const_at() method.
 *
 * @param[in] n index number.
 *
 * @return const_reference to element number n in underlying array.
 *
 * @throw std::out_of_range if n is not within the range of the container.
 */
template <typename T>
typename vector<T>::const_reference
vector<T>::const_at(size_type n) const
{
	if (n >= _size)
		throw std::out_of_range("vector::const_at");

	return _data[static_cast<difference_type>(n)];
}

/**
 * Access element at specific index and add it to a transaction. No bounds
 * checking is performed.
 *
 * @param[in] n index number.
 *
 * @return reference to element number n in underlying array.
 *
 * @throw pmem::transaction_error when adding the object to the transaction
 * failed.
 */
template <typename T>
typename vector<T>::reference vector<T>::operator[](size_type n)
{
	detail::conditional_add_to_tx(&_data[static_cast<difference_type>(n)],
				      1, POBJ_XADD_ASSUME_INITIALIZED);

	return _data[static_cast<difference_type>(n)];
}

/**
 * Access element at specific index. No bounds checking is performed.
 *
 * @param[in] n index number.
 *
 * @return const_reference to element number n in underlying array.
 */
template <typename T>
typename vector<T>::const_reference vector<T>::operator[](size_type n) const
{
	return _data[static_cast<difference_type>(n)];
}

/**
 * Access the first element and add this element to a transaction.
 *
 * @return reference to first element in underlying array.
 *
 * @throw pmem::transaction_error when adding the object to the transaction
 * failed.
 */
template <typename T>
typename vector<T>::reference
vector<T>::front()
{
	detail::conditional_add_to_tx(&_data[0], 1,
				      POBJ_XADD_ASSUME_INITIALIZED);

	return _data[0];
}

/**
 * Access the first element.
 *
 * @return const_reference to first element in underlying array.
 */
template <typename T>
typename vector<T>::const_reference
vector<T>::front() const
{
	return _data[0];
}

/**
 * Access the first element. In contradiction to front(), cfront() will return
 * const_reference not depending on the const-qualification of the object it is
 * called on. std::vector doesn't provide cfront() method.
 *
 * @return reference to first element in underlying array.
 */
template <typename T>
typename vector<T>::const_reference
vector<T>::cfront() const
{
	return _data[0];
}

/**
 * Access the last element and add this element to a transaction.
 *
 * @return reference to the last element in underlying array.
 *
 * @throw pmem::transaction_error when adding the object to the transaction
 * failed.
 */
template <typename T>
typename vector<T>::reference
vector<T>::back()
{
	detail::conditional_add_to_tx(
		&_data[static_cast<difference_type>(size() - 1)], 1,
		POBJ_XADD_ASSUME_INITIALIZED);

	return _data[static_cast<difference_type>(size() - 1)];
}

/**
 * Access the last element.
 *
 * @return const_reference to the last element in underlying array.
 */
template <typename T>
typename vector<T>::const_reference
vector<T>::back() const
{
	return _data[static_cast<difference_type>(size() - 1)];
}

/**
 * Access the last element. In contradiction to back(), cback() will return
 * const_reference not depending on the const-qualification of the object it is
 * called on. std::vector doesn't provide cback() method.
 *
 * @return const_reference to the last element in underlying array.
 */
template <typename T>
typename vector<T>::const_reference
vector<T>::cback() const
{
	return _data[static_cast<difference_type>(size() - 1)];
}

/**
 * Returns raw pointer to the underlying data and adds entire array to a
 * transaction.
 *
 * @return pointer to the underlying data.
 *
 * @throw pmem::transaction_error when adding the object to the transaction
 * failed.
 */
template <typename T>
typename vector<T>::value_type *
vector<T>::data()
{
	add_data_to_tx(0, _size);

	return _data.get();
}

/**
 * Returns const raw pointer to the underlying data.
 *
 * @return const_pointer to the underlying data.
 */
template <typename T>
const typename vector<T>::value_type *
vector<T>::data() const noexcept
{
	return _data.get();
}

/**
 * Returns const raw pointer to the underlying data. In contradiction to data(),
 * cdata() will return const_pointer not depending on the const-qualification of
 * the object it is called on. std::vector doesn't provide cdata() method.
 *
 * @return const_pointer to the underlying data.
 */
template <typename T>
const typename vector<T>::value_type *
vector<T>::cdata() const noexcept
{
	return _data.get();
}

/**
 * Returns an iterator to the beginning.
 *
 * @return iterator pointing to the first element in the vector.
 */
template <typename T>
typename vector<T>::iterator
vector<T>::begin()
{
	return iterator(_data.get());
}

/**
 * Returns const iterator to the beginning.
 *
 * @return const_iterator pointing to the first element in the vector.
 */
template <typename T>
typename vector<T>::const_iterator
vector<T>::begin() const noexcept
{
	return const_iterator(_data.get());
}

/**
 * Returns const iterator to the beginning. In contradiction to begin(),
 * cbegin() will return const_iterator not depending on the const-qualification
 * of the object it is called on.
 *
 * @return const_iterator pointing to the first element in the vector.
 */
template <typename T>
typename vector<T>::const_iterator
vector<T>::cbegin() const noexcept
{
	return const_iterator(_data.get());
}

/**
 * Returns an iterator to past the end.
 *
 * @return iterator referring to the past-the-end element in the vector.
 */
template <typename T>
typename vector<T>::iterator
vector<T>::end()
{
	return iterator(_data.get() + static_cast<std::ptrdiff_t>(_size));
}

/**
 * Returns a const iterator to past the end.
 *
 * @return const_iterator referring to the past-the-end element in the vector.
 */
template <typename T>
typename vector<T>::const_iterator
vector<T>::end() const noexcept
{
	return const_iterator(_data.get() + static_cast<std::ptrdiff_t>(_size));
}

/**
 * Returns a const iterator to the end. In contradiction to end(), cend() will
 * return const_iterator not depending on the const-qualification of the object
 * it is called on.
 *
 * @return const_iterator referring to the past-the-end element in the vector.
 */
template <typename T>
typename vector<T>::const_iterator
vector<T>::cend() const noexcept
{
	return const_iterator(_data.get() + static_cast<std::ptrdiff_t>(_size));
}

/**
 * Returns a reverse iterator to the beginning.
 *
 * @return reverse_iterator pointing to the last element in the vector.
 */
template <typename T>
typename vector<T>::reverse_iterator
vector<T>::rbegin()
{
	return reverse_iterator(end());
}

/**
 * Returns a const reverse iterator to the beginning.
 *
 * @return const_reverse_iterator pointing to the last element in the vector.
 */
template <typename T>
typename vector<T>::const_reverse_iterator
vector<T>::rbegin() const noexcept
{
	return const_reverse_iterator(cend());
}

/**
 * Returns a const reverse iterator to the beginning. In contradiction to
 * rbegin(), crbegin() will return const_reverse_iterator not depending on the
 * const-qualification of the object it is called on.
 *
 * @return const_reverse_iterator pointing to the last element in the vector.
 */
template <typename T>
typename vector<T>::const_reverse_iterator
vector<T>::crbegin() const noexcept
{
	return const_reverse_iterator(cend());
}

/**
 * Returns a reverse iterator to the end.
 *
 * @return reverse_iterator pointing to the theoretical element preceding the
 * first element in the vector.
 */
template <typename T>
typename vector<T>::reverse_iterator
vector<T>::rend()
{
	return reverse_iterator(begin());
}

/**
 * Returns a const reverse iterator to the end.
 *
 * @return const_reverse_iterator pointing to the theoretical element preceding
 * the first element in the vector.
 */
template <typename T>
typename vector<T>::const_reverse_iterator
vector<T>::rend() const noexcept
{
	return const_reverse_iterator(cbegin());
}

/**
 * Returns a const reverse iterator to the beginning. In contradiction to
 * rend(), crend() will return const_reverse_iterator not depending on the
 * const-qualification of the object it is called on.
 *
 * @return const_reverse_iterator pointing to the theoretical element preceding
 * the first element in the vector.
 */
template <typename T>
typename vector<T>::const_reverse_iterator
vector<T>::crend() const noexcept
{
	return const_reverse_iterator(cbegin());
}

/**
 * Returns slice and snapshots requested range. This method is not specified by
 * STL standards.
 *
 * @param[in] start start index of requested range.
 * @param[in] n number of elements in range.
 *
 * @return pmem::obj::slice from start to start + n.
 *
 * @throw std::out_of_range if any element of the range would be outside of the
 * vector.
 * @throw pmem::transaction_error when snapshotting failed.
 */
template <typename T>
slice<typename vector<T>::pointer>
vector<T>::range(size_type start, size_type n)
{
	if (start + n > size())
		throw std::out_of_range("vector::range");

	detail::conditional_add_to_tx(cdata() + start, n,
				      POBJ_XADD_ASSUME_INITIALIZED);

	return {_data.get() + start, _data.get() + start + n};
}

/**
 * Returns slice. This method is not specified by STL standards.
 *
 * @param[in] start start index of requested range.
 * @param[in] n number of elements in range.
 * @param[in] snapshot_size number of elements which should be snapshotted in a
 * bulk while traversing this slice. If provided value is larger or equal to n,
 * entire range is added to a transaction. If value is equal to 0 no
 * snapshotting happens.
 *
 * @return pmem::obj::slice from start to start + n.
 *
 * @throw std::out_of_range if any element of the range would be outside of the
 * vector.
 */
template <typename T>
slice<typename vector<T>::range_snapshotting_iterator>
vector<T>::range(size_type start, size_type n, size_type snapshot_size)
{
	if (start + n > size())
		throw std::out_of_range("vector::range");

	if (snapshot_size > n)
		snapshot_size = n;

	return {range_snapshotting_iterator(_data.get() + start,
					    _data.get() + start, n,
					    snapshot_size),
		range_snapshotting_iterator(_data.get() + start + n,
					    _data.get() + start, n,
					    snapshot_size)};
}

/**
 * Returns const slice. This method is not specified by STL standards.
 *
 * @param[in] start start index of requested range.
 * @param[in] n number of elements in range.
 *
 * @return pmem::obj::slice from start to start + n.
 *
 * @throw std::out_of_range if any element of the range would be outside of the
 * vector.
 */
template <typename T>
slice<typename vector<T>::const_iterator>
vector<T>::range(size_type start, size_type n) const
{
	if (start + n > size())
		throw std::out_of_range("vector::range");

	return {const_iterator(cdata() + start),
		const_iterator(cdata() + start + n)};
}

/**
 * Returns const slice. This method is not specified by STL standards.
 *
 * @param[in] start start index of requested range.
 * @param[in] n number of elements in range.
 *
 * @return pmem::obj::slice from start to start + n.
 *
 * @throw std::out_of_range if any element of the range would be outside of the
 * vector.
 */
template <typename T>
slice<typename vector<T>::const_iterator>
vector<T>::crange(size_type start, size_type n) const
{
	if (start + n > size())
		throw std::out_of_range("vector::crange");

	return {const_iterator(cdata() + start),
		const_iterator(cdata() + start + n)};
}

/**
 * Checks whether the container is empty.
 *
 * @return true if container is empty, false otherwise.
 */
template <typename T>
constexpr bool
vector<T>::empty() const noexcept
{
	return _size == 0;
}

/**
 * @return number of elements.
 */
template <typename T>
typename vector<T>::size_type
vector<T>::size() const noexcept
{
	return _size;
}

/**
 * @return maximum number of elements the container is able to hold due to PMDK
 * limitations.
 */
template <typename T>
constexpr typename vector<T>::size_type
vector<T>::max_size() const noexcept
{
	return PMEMOBJ_MAX_ALLOC_SIZE / sizeof(value_type);
}

/**
 * Increases the capacity of the vector to capacity_new transactionally. If
 * capacity_new is greater than the current capacity(), new storage is
 * allocated, otherwise the method does nothing. If capacity_new is greater than
 * capacity(), all iterators, including the past-the-end iterator, and all
 * references to the elements are invalidated. Otherwise, no iterators or
 * references are invalidated.
 *
 * @param[in] capacity_new new capacity.
 *
 * @post capacity() == max(capacity(), capacity_new)
 *
 * @throw rethrows destructor exception.
 * @throw std::length_error if new_cap > max_size().
 * @throw pmem::transaction_error when snapshotting failed.
 * @throw pmem::transaction_alloc_error when allocating new memory failed.
 * @throw pmem::transaction_free_error when freeing old underlying array failed.
 */
template <typename T>
void
vector<T>::reserve(size_type capacity_new)
{
	if (capacity_new <= _capacity)
		return;

	pool_base pb = get_pool();
	flat_transaction::run(pb, [&] { realloc(capacity_new); });
}

/**
 * @return number of elements that can be held in currently allocated storage
 */
template <typename T>
typename vector<T>::size_type
vector<T>::capacity() const noexcept
{
	return _capacity;
}

/**
 * Requests transactional removal of unused capacity. New capacity will be set
 * to current vector size. If reallocation occurs, all iterators, including the
 * past the end iterator, and all references to the elements are invalidated.
 * If no reallocation takes place, no iterators or references are invalidated.
 *
 * @post capacity() == size()
 *
 * @throw pmem::transaction_error when snapshotting failed
 * @throw pmem::transaction_alloc_error when reallocating failed.
 * @throw pmem::transaction_free_error when freeing old underlying array failed.
 * @throw rethrows constructor's exception.
 * @throw rethrows destructor exception.
 */
template <typename T>
void
vector<T>::shrink_to_fit()
{
	size_type capacity_new = size();
	if (capacity() == capacity_new)
		return;

	pool_base pb = get_pool();
	flat_transaction::run(pb, [&] { realloc(capacity_new); });
}

/**
 * Clears the content of a vector transactionally.
 *
 * @post size() == 0
 *
 * @throw pmem::transaction_error when snapshotting failed.
 * @throw rethrows destructor exception.
 */
template <typename T>
void
vector<T>::clear()
{
	pool_base pb = get_pool();
	flat_transaction::run(pb, [&] { shrink(0); });
}

/**
 * Clears the content of a vector and frees all allocated persistent memory for
 * data transactionally.
 *
 * @post size() == 0
 * @post capacity() == 0
 * @post data() == nullptr
 *
 * @throw pmem::transaction_error when snapshotting failed.
 * @throw rethrows destructor exception.
 * @throw pmem::transaction_free_error when freeing underlying array failed.
 */
template <typename T>
void
vector<T>::free_data()
{
	if (_data == nullptr)
		return;

	pool_base pb = get_pool();
	flat_transaction::run(pb, [&] { dealloc(); });
}

/**
 * Inserts value before pos in the container transactionally. Causes
 * reallocation if the new size() is greater than the old capacity(). If the new
 * size() is greater than capacity(), all iterators and references are
 * invalidated. Otherwise, only the iterators and references before the
 * insertion point remain valid. The past-the-end iterator is also invalidated.
 *
 * @param[in] pos iterator before which the content will be inserted. pos may be
 * the end() iterator.
 * @param[in] value element value to be inserted.
 *
 * @return Iterator pointing to the inserted value.
 *
 * @pre value_type must meet the requirements of CopyAssignable and
 * CopyInsertable.
 *
 * @post capacity() is equal to the smallest next power of 2, bigger than old
 * capacity, or remains the same if there is enough space to add single element.
 *
 * @throw pmem::transaction_error when snapshotting failed.
 * @throw rethrows constructor's exception.
 * @throw rethrows destructor exception.
 * @throw pmem::transaction_free_error when freeing old underlying array failed.
 */
template <typename T>
typename vector<T>::iterator
vector<T>::insert(const_iterator pos, const value_type &value)
{
	return insert(pos, 1, value);
}

/**
 * Moves value before pos in the container transactionally. Causes reallocation
 * if the new size() is greater than the old capacity(). If the new size() is
 * greater than capacity(), all iterators and references are invalidated.
 * Otherwise, only the iterators and references before the insertion point
 * remain valid. The past-the-end iterator is also invalidated.
 *
 * @param[in] pos iterator before which the content will be inserted. pos may be
 * the end() iterator.
 * @param[in] value element value to be inserted.
 *
 * @return Iterator pointing to the inserted value.
 *
 * @pre value_type must meet the requirements of MoveAssignable and
 * MoveInsertable.
 *
 * @post capacity() is equal to the smallest next power of 2, bigger than old
 * capacity, or remains the same if there is enough space to add single element.
 *
 * @throw pmem::transaction_error when snapshotting failed.
 * @throw rethrows constructor's exception.
 * @throw rethrows destructor exception.
 * @throw pmem::transaction_free_error when freeing old underlying array failed.
 */
template <typename T>
typename vector<T>::iterator
vector<T>::insert(const_iterator pos, value_type &&value)
{
	pool_base pb = get_pool();

	size_type idx = static_cast<size_type>(std::distance(cbegin(), pos));

	flat_transaction::run(pb, [&] {
		internal_insert(idx, std::make_move_iterator(&value),
				std::make_move_iterator(&value + 1));
	});

	return iterator(&_data[static_cast<difference_type>(idx)]);
}

/**
 * Inserts count copies of the value before pos in the container
 * transactionally. Causes reallocation if the new size() is greater than the
 * old capacity(). If the new size() is greater than capacity(), all iterators
 * and references are invalidated. Otherwise, only the iterators and references
 * before the insertion point remain valid. The past-the-end iterator is also
 * invalidated.
 *
 * @param[in] pos iterator before which the content will be inserted. pos may be
 * the end() iterator.
 * @param[in] count number of copies to be inserted.
 * @param[in] value element value to be inserted.
 *
 * @return Iterator pointing to the first element inserted, or pos if count ==
 * 0.
 *
 * @pre value_type must meet the requirements of CopyAssignable and
 * CopyInsertable.
 *
 * @post capacity() is equal to the smallest next power of 2, bigger than old
 * capacity + count, or remains the same if there is enough space to add count
 * elements.
 *
 * @throw pmem::transaction_error when snapshotting failed.
 * @throw rethrows constructor's exception.
 * @throw rethrows destructor exception.
 * @throw pmem::transaction_free_error when freeing old underlying array failed.
 */
template <typename T>
typename vector<T>::iterator
vector<T>::insert(const_iterator pos, size_type count, const value_type &value)
{
	pool_base pb = get_pool();

	size_type idx = static_cast<size_type>(std::distance(cbegin(), pos));

	flat_transaction::run(pb, [&] {
		internal_insert(
			idx, single_element_iterator<value_type>(&value, 0),
			single_element_iterator<value_type>(&value, count));
	});

	return iterator(_data.get() + static_cast<difference_type>(idx));
}

/**
 * Inserts elements from range [first, last) before pos in the container
 * transactionally. Causes reallocation if the new size() is greater than the
 * old capacity(). If the new size() is greater than capacity(), all iterators
 * and references are invalidated. Otherwise, only the iterators and references
 * before the insertion point remain valid. The past-the-end iterator is also
 * invalidated. This overload participates in overload resolution only if
 * InputIt qualifies as InputIterator, to avoid ambiguity with the
 * pos-count-value overload. The behavior is undefined if first and last are
 * iterators into *this.
 *
 * @param[in] pos iterator before which the content will be inserted. pos may be
 * the end() iterator.
 * @param[in] first begin of the range of elements to insert, can't be iterator
 * into container for which insert is called.
 * @param[in] last end of the range of elements to insert, can't be iterator
 * into container for which insert is called.
 *
 * @return Iterator pointing to the first element inserted or pos if first ==
 * last.
 *
 * @pre value_type must meet the requirements of EmplaceConstructible,
 * Swappable, CopyAssignable, CopyConstructible and CopyInsertable.
 * @pre InputIt must satisfies requirements of InputIterator.
 *
 * @post capacity() is equal to the smallest next power of 2, bigger than old
 * capacity + std::distance(first, last), or remains the same if there is enough
 * space to add std::distance(first, last) elements.
 *
 * @throw pmem::transaction_error when snapshotting failed.
 * @throw rethrows constructor's exception.
 * @throw rethrows destructor exception.
 * @throw pmem::transaction_free_error when freeing old underlying array failed.
 */
template <typename T>
template <typename InputIt,
	  typename std::enable_if<detail::is_input_iterator<InputIt>::value,
				  InputIt>::type *>
typename vector<T>::iterator
vector<T>::insert(const_iterator pos, InputIt first, InputIt last)
{
	pool_base pb = get_pool();

	size_type idx = static_cast<size_type>(std::distance(cbegin(), pos));

	flat_transaction::run(pb, [&] { internal_insert(idx, first, last); });

	return iterator(&_data[static_cast<difference_type>(idx)]);
}

/**
 * Inserts elements from initializer list ilist before pos in the container
 * transactionally. Causes reallocation if the new size() is greater than the
 * old capacity(). If the new size() is greater than capacity(), all iterators
 * and references are invalidated. Otherwise, only the iterators and references
 * before the insertion point remain valid. The past-the-end iterator is also
 * invalidated.
 *
 * @param[in] pos iterator before which the content will be inserted. pos may be
 * the end() iterator.
 * @param[in] ilist initializer list to insert the values from.
 *
 * @return Iterator pointing to the first element inserted, or pos if ilist is
 * empty.
 *
 * @pre value_type must meet the requirements of EmplaceConstructible,
 * Swappable, CopyAssignable, CopyConstructible and CopyInsertable.
 *
 * @post capacity() is equal to the smallest next power of 2, bigger than old
 * capacity + std::distance(ilist.begin(), ilist.end()), or remains the same if
 * there is enough space to add std::distance(ilist.begin(), ilist.end())
 * elements.
 *
 * @throw pmem::transaction_error when snapshotting failed.
 * @throw rethrows constructor's exception.
 * @throw rethrows destructor exception.
 * @throw pmem::transaction_free_error when freeing old underlying array failed.
 */
template <typename T>
typename vector<T>::iterator
vector<T>::insert(const_iterator pos, std::initializer_list<value_type> ilist)
{
	return insert(pos, ilist.begin(), ilist.end());
}

/**
 * Inserts a new element into the container directly before pos. The element is
 * constructed in-place. The arguments args... are forwarded to the constructor
 * as std::forward<Args>(args).... If the new size() is greater than capacity(),
 * all iterators and references are invalidated. Otherwise, only the iterators
 * and references before the insertion point remain valid. The past-the-end
 * iterator is also invalidated. Note that standard allows args to be a self
 * reference and internal emplace implementation handles this case by creating
 * temporary element_type object. This object is being stored either on stack or
 * on pmem, see pmem::detail::temp_value for details.
 *
 * @param[in] pos iterator before which the new element will be constructed.
 * @param[in] args arguments to forward to the constructor of the element.
 *
 * @return Iterator pointing to the emplaced element.
 *
 * @pre value_type must meet the requirements of MoveAssignable, MoveInsertable
 * and EmplaceConstructible.
 *
 * @post capacity() is equal to the smallest next power of 2, bigger than old
 * capacity, or remains the same if there is enough space to add single element.
 *
 * @throw pmem::transaction_error when snapshotting failed.
 * @throw rethrows constructor's exception.
 * @throw rethrows destructor exception.
 * @throw pmem::transaction_free_error when freeing old underlying array failed.
 */
template <typename T>
template <class... Args>
typename vector<T>::iterator
vector<T>::emplace(const_iterator pos, Args &&... args)
{
	pool_base pb = get_pool();

	size_type idx = static_cast<size_type>(std::distance(cbegin(), pos));

	flat_transaction::run(pb, [&] {
		/*
		 * args might be a reference to underlying array element. This
		 * reference can be invalidated after internal_insert() call.
		 * Hence, we must cache value_type object in temp_value.
		 */
		detail::temp_value<value_type,
				   noexcept(T(std::forward<Args>(args)...))>
		tmp(std::forward<Args>(args)...);

		auto &tmp_ref = tmp.get();

		internal_insert(idx, std::make_move_iterator(&tmp_ref),
				std::make_move_iterator(&tmp_ref + 1));
	});

	return iterator(&_data[static_cast<difference_type>(idx)]);
}

/**
 * Appends a new element to the end of the container. The element is constructed
 * in-place. The arguments args... are forwarded to the constructor as
 * std::forward<Args>(args).... If the new size() is greater than capacity()
 * then all iterators and references (including the past-the-end iterator) are
 * invalidated. Otherwise only the past-the-end iterator is invalidated.
 *
 * @param[in] args arguments to forward to the constructor of the element.
 *
 * @return Iterator pointing to the emplaced element.
 *
 * @pre value_type must meet the requirements of MoveInsertable and
 * EmplaceConstructible.
 *
 * @post capacity() is equal to the smallest next power of 2, bigger than old
 * capacity, or remains the same if there is enough space to add single element.
 *
 * @throw pmem::transaction_error when snapshotting failed.
 * @throw rethrows constructor's exception.
 * @throw rethrows destructor exception.
 * @throw pmem::transaction_free_error when freeing old underlying array failed.
 */
template <typename T>
template <class... Args>
typename vector<T>::reference
vector<T>::emplace_back(Args &&... args)
{
	/*
	 * emplace() cannot be used here, because emplace_back() doesn't require
	 * element_type to be MoveAssignable and emplace() uses
	 * std::move_backward() function.
	 */
	pool_base pb = get_pool();

	flat_transaction::run(pb, [&] {
		if (_size == _capacity) {
			realloc(get_recommended_capacity(_size + 1));
		} else {
			add_data_to_tx(size(), 1);
		}

		construct_at_end(1, std::forward<Args>(args)...);
	});

	return back();
}

/**
 * Removes the element at pos. Invalidates iterators and references at or after
 * the point of the erase, including the end() iterator. The iterator pos must
 * be valid and dereferenceable. Thus the end() iterator (which is valid, but is
 * not dereferenceable) cannot be used as a value for pos.
 *
 * @param[in] pos iterator to the element to be removed.
 *
 * @return Iterator following the last removed element. If the iterator pos
 * refers to the last element, the end() iterator is returned.
 *
 * @pre value_type must meet the requirements of MoveAssignable.
 *
 * @post size() = size() - 1.
 *
 * @throw pmem::transaction_error when snapshotting failed.
 * @throw rethrows constructor's exception.
 * @throw rethrows destructor exception.
 */
template <typename T>
typename vector<T>::iterator
vector<T>::erase(const_iterator pos)
{
	return erase(pos, pos + 1);
}

/**
 * Removes the elements in the range [first, last). Invalidates iterators and
 * references at or after the point of the erase, including the end() iterator.
 * The iterator pos must be valid and dereferenceable. Thus the end() iterator
 * (which is valid, but is not dereferenceable) cannot be used as a value for
 * pos.
 *
 * @param[in] first beginning of the range of elements to be removed.
 * @param[in] last end of range of elements to be removed.
 *
 * @return Iterator following the last removed element. If the iterator pos
 * refers to the last element, the end() iterator is returned. If first and last
 * refer to the same element, iterator to this element is returned.
 *
 * @pre value_type must meet the requirements of MoveAssignable.
 *
 * @post size() = size() - std::distance(first, last).
 *
 * @throw pmem::transaction_error when snapshotting failed.
 * @throw rethrows constructor's exception.
 * @throw rethrows destructor exception.
 */
template <typename T>
typename vector<T>::iterator
vector<T>::erase(const_iterator first, const_iterator last)
{
	size_type idx = static_cast<size_type>(
		std::distance(const_iterator(_data.get()), first));
	size_type count = static_cast<size_type>(std::distance(first, last));

	if (count == 0)
		return iterator(&_data[static_cast<difference_type>(idx)]);

	pool_base pb = get_pool();

	flat_transaction::run(pb, [&] {
		if (!std::is_trivially_destructible<T>::value ||
		    idx + count < _size)
			add_data_to_tx(idx, _size - idx);

		pointer move_begin =
			&_data[static_cast<difference_type>(idx + count)];
		pointer move_end = &_data[static_cast<difference_type>(size())];
		pointer dest = &_data[static_cast<difference_type>(idx)];

		std::move(move_begin, move_end, dest);

		_size -= count;
	});

	return iterator(&_data[static_cast<difference_type>(idx)]);
}

/**
 * Appends the given element value to the end of the container transactionally.
 * The new element is initialized as a copy of value.
 *
 * @param[in] value the value of the element to be appended.
 *
 * @pre value_type must meet the requirements of CopyInsertable.
 *
 * @post capacity() is equal to the smallest next power of 2, bigger than old
 * capacity, or remains the same if there is enough space to add single element.
 *
 * @throw transaction_error when snapshotting failed.
 * @throw rethrows constructor's exception.
 * @throw pmem::transaction_free_error when freeing old underlying array failed.
 */
template <typename T>
void
vector<T>::push_back(const value_type &value)
{
	emplace_back(value);
}

/**
 * Appends the given element value to the end of the container transactionally.
 * value is moved into the new element.
 *
 * @param[in] value the value of the element to be appended.
 *
 * @pre value_type must meet the requirements of MoveInsertable.
 *
 * @post size() == size() + 1
 * @post capacity() is equal to the smallest next power of 2, bigger than old
 * capacity, or remains the same if there is enough space to add single element.
 *
 * @throw transaction_error when snapshotting failed.
 * @throw rethrows constructor's exception.
 * @throw pmem::transaction_free_error when freeing old underlying array failed.
 */
template <typename T>
void
vector<T>::push_back(value_type &&value)
{
	emplace_back(std::move(value));
}

/**
 * Removes the last element of the container transactionally. Calling pop_back
 * on an empty container does nothing. No iterators or references except for
 * back() and end() are invalidated.
 *
 * @post size() == std::max(0, size() - 1)
 *
 * @throw transaction_error when snapshotting failed.
 * @throw rethrows destructor exception.
 */
template <typename T>
void
vector<T>::pop_back()
{
	if (empty())
		return;

	pool_base pb = get_pool();
	flat_transaction::run(pb, [&] { shrink(size() - 1); });
}

/**
 * Resizes the container to count elements transactionally. If the current size
 * is greater than count, the container is reduced to its first count elements.
 * If the current size is less than count, additional default-inserted elements
 * are appended.
 *
 * @param[in] count new size of the container
 *
 * @post capacity() == std::max(count, capacity())
 * @post size() == count
 *
 * @throw rethrows constructor's exception.
 * @throw rethrows destructor exception.
 * @throw pmem::transaction_error when snapshotting failed.
 * @throw pmem::transaction_free_error when freeing old underlying array failed.
 */
template <typename T>
void
vector<T>::resize(size_type count)
{
	pool_base pb = get_pool();
	flat_transaction::run(pb, [&] {
		if (count <= _size)
			shrink(count);
		else {
			if (_capacity < count)
				realloc(count);
			construct_at_end(count - _size);
		}
	});
}

/**
 * Resizes the container to contain count elements transactionally. If the
 * current size is greater than count, the container is reduced to its first
 * count elements. If the current size is less than count, additional copies of
 * value are appended.
 *
 * @param[in] count new size of the container.
 * @param[in] value the value to initialize the new elements with.
 *
 * @post capacity() == count
 * @post size() == std::min(_size, count)
 *
 * @throw rethrows constructor's exception.
 * @throw rethrows destructor exception.
 * @throw pmem::transaction_error when snapshotting failed.
 * @throw pmem::transaction_free_error when freeing old underlying array failed.
 */
template <typename T>
void
vector<T>::resize(size_type count, const value_type &value)
{
	if (_capacity == count)
		return;

	pool_base pb = get_pool();
	flat_transaction::run(pb, [&] {
		if (count <= _size)
			shrink(count);
		else {
			if (_capacity < count)
				realloc(count);
			construct_at_end(count - _size, value);
		}
	});
}

/**
 * Exchanges the contents of the container with other transactionally.
 */
template <typename T>
void
vector<T>::swap(vector &other)
{
	pool_base pb = get_pool();
	flat_transaction::run(pb, [&] {
		std::swap(this->_data, other._data);
		std::swap(this->_size, other._size);
		std::swap(this->_capacity, other._capacity);
	});
}

/**
 * Iterates over all internal pointers and executes a callback function
 * on each of them. In this implementation, it is just a single pointer.
 *
 * @param func callback function to call on internal pointer.
 */
template <typename T>
void
vector<T>::for_each_ptr(for_each_ptr_function func)
{
	func(_data);
}

/**
 * Private helper function. Must be called during transaction. Allocates memory
 * for given number of elements.
 *
 * @param[in] capacity_new capacity of new underlying array.
 *
 * @pre must be called in transaction scope.
 * @pre data() == nullptr
 * @pre size() == 0
 *
 * @post capacity() == capacity_new
 *
 * @throw std::length_error if new size exceeds biggest possible pmem
 * allocation.
 * @throw pmem::transaction_alloc_error when allocating memory for underlying
 * array in transaction failed.
 */
template <typename T>
void
vector<T>::alloc(size_type capacity_new)
{
	assert(pmemobj_tx_stage() == TX_STAGE_WORK);
	assert(_data == nullptr);
	assert(_size == 0);

	if (capacity_new > max_size())
		throw std::length_error("New capacity exceeds max size.");

	_capacity = capacity_new;

	if (capacity_new == 0)
		return;

	/*
	 * We need to cache pmemobj_tx_alloc return value and only after that
	 * assign it to _data, because when pmemobj_tx_alloc fails, it aborts
	 * transaction.
	 */
	persistent_ptr<T[]> res =
		pmemobj_tx_alloc(sizeof(value_type) * capacity_new,
				 detail::type_num<value_type>());

	if (res == nullptr) {
		const char *msg = "Failed to allocate persistent memory object";
		if (errno == ENOMEM)
			throw detail::exception_with_errormsg<
				pmem::transaction_out_of_memory>(msg);
		else
			throw detail::exception_with_errormsg<
				pmem::transaction_alloc_error>(msg);
	}
	_data = res;
}

/**
 * Private helper function. Checks if vector resides on pmem and throws an
 * exception if not.
 *
 * @throw pool_error if vector doesn't reside on pmem.
 */
template <typename T>
void
vector<T>::check_pmem()
{
	if (nullptr == pmemobj_pool_by_ptr(this))
		throw pmem::pool_error("Invalid pool handle.");
}

/**
 * Private helper function. Checks if current transaction stage is equal to
 * TX_STAGE_WORK and throws an exception otherwise.
 *
 * @throw pmem::transaction_scope_error if current transaction stage is not
 * equal to TX_STAGE_WORK.
 */
template <typename T>
void
vector<T>::check_tx_stage_work()
{
	if (pmemobj_tx_stage() != TX_STAGE_WORK)
		throw pmem::transaction_scope_error(
			"Function called out of transaction scope.");
}

/**
 * Private helper function. Must be called during transaction. Assumes that
 * there is free space for additional elements. Constructs elements at
 * index size() in underlying array based on given parameters.
 *
 * @param[in] count number of elements to be constructed.
 * @param[in] args variadic template arguments for value_type constructor.
 *
 * @pre must be called in transaction scope.
 * @pre if initialized, range [end(), end() + count) must be snapshotted in
 * current transaction.
 * @pre capacity() >= count + size()
 * @pre args is valid argument for value_type constructor.
 *
 * @post size() == size() + count
 *
 * @throw rethrows constructor's exception.
 */
template <typename T>
template <typename... Args>
void
vector<T>::construct_at_end(size_type count, Args &&... args)
{
	assert(pmemobj_tx_stage() == TX_STAGE_WORK);
	assert(_capacity >= count + _size);

	pointer dest = _data.get() + size();
	const_pointer end = dest + count;
	for (; dest != end; ++dest)
		detail::create<value_type, Args...>(
			dest, std::forward<Args>(args)...);
	_size += count;
}

/**
 * Private helper function. Must be called during transaction. Assumes that
 * there is free space for additional elements and input arguments satisfy
 * InputIterator requirements. Copies elements at index size() in underlying
 * array with the contents of the range [first, last). This overload
 * participates in overload resolution only if InputIt satisfies InputIterator.
 *
 * @param[in] first first iterator.
 * @param[in] last last iterator.
 *
 * @pre must be called in transaction scope.
 * @pre if initialized, range [end(), end() + std::distance(first, last)) must
 * be snapshotted in current transaction.
 * @pre capacity() >= std::distance(first, last) + size()
 * @pre InputIt is InputIterator.
 * @pre InputIt::reference is valid argument for value_type
 * constructor.
 *
 * @post size() == size() + std::distance(first, last)
 *
 * @throw rethrows constructor's exception.
 */
template <typename T>
template <typename InputIt,
	  typename std::enable_if<detail::is_input_iterator<InputIt>::value,
				  InputIt>::type *>
void
vector<T>::construct_at_end(InputIt first, InputIt last)
{
	assert(pmemobj_tx_stage() == TX_STAGE_WORK);
	difference_type range_size = std::distance(first, last);
	assert(range_size >= 0);
	assert(_capacity >= static_cast<size_type>(range_size) + _size);

	pointer dest = _data.get() + size();
	_size += static_cast<size_type>(range_size);
	while (first != last)
		detail::create<value_type>(dest++, *first++);
}

/**
 * Private helper function. Must be called during transaction. Deallocates
 * underlying array.
 *
 * @pre must be called in transaction scope.
 *
 * @post size() == 0
 * @post capacity() == 0
 * @post data() == nullptr
 *
 * @throw pmem::transaction_error when snapshotting failed.
 * @throw rethrows destructor exception.
 * @throw pmem::transaction_free_error when freeing old underlying array
 * failed.
 */
template <typename T>
void
vector<T>::dealloc()
{
	assert(pmemobj_tx_stage() == TX_STAGE_WORK);

	if (_data != nullptr) {
		shrink(0);
		if (pmemobj_tx_free(*_data.raw_ptr()) != 0)
			throw detail::exception_with_errormsg<
				pmem::transaction_free_error>(
				"failed to delete persistent memory object");
		_data = nullptr;
		_capacity = 0;
	}
}

/**
 * Private helper function.
 *
 * @return reference to pool_base object where vector resides.
 *
 * @pre underlying array must reside in persistent memory pool.
 */
template <typename T>
pool_base
vector<T>::get_pool() const
{
	return pmem::obj::pool_by_vptr(this);
}

/**
 * Private helper function.
 *
 * It behaves similarly to std::move_backward but uses either
 * copy constructor in case destination memory is not initialized
 * or copy assignment operator otherwise.
 */
template <typename T>
void
vector<T>::move_elements_backward(pointer first, pointer last, pointer d_last)
{
	while (first != last && d_last >= cend())
		detail::create<value_type>(--d_last, std::move(*(--last)));

	if (first != last)
		std::move_backward(first, last, d_last);
}

/**
 * Private helper function.
 *
 * It behaves similarly to std::move_backward but uses either
 * copy constructor in case destination memory is not initialized
 * or copy assignment operator otherwise.
 */
template <typename T>
template <typename InputIt>
void
vector<T>::construct_or_assign(size_type idx, InputIt first, InputIt last)
{
	auto count = static_cast<size_type>(std::distance(first, last));
	auto dest = _data.get() + idx;
	auto initialized_slots = static_cast<size_type>(cend() - dest);

	/* Assign new elements to initialized memory */
	if (dest < cend())
		dest = std::copy_n(first, (std::min)(initialized_slots, count),
				   dest);

	std::advance(first, (std::min)(initialized_slots, count));

	/* Rest of the elements will be created in uninitialized memory */
	while (first != last)
		detail::create<value_type>(dest++, *first++);

	_size += count;
}

/**
 * Private helper function. Must be called during transaction. Inserts a gap for
 * count elements starting at index idx. If there is not enough space available,
 * reallocation occurs with new recommended size. Range specified by first, last
 * is then inserted into the gap.
 *
 * @param[in] idx index number where insert should be made
 * @param[in] first iterator to beginning of the range to insert
 * @param[in] last iterator to end of the range to insert
 *
 * @pre must be called in transaction scope.
 *
 * @post if there is not enough space for additional gap, capacity changes to
 * get_recommended_capacity().
 *
 * @throw pmem::transaction_error when snapshotting failed.
 * @throw rethrows constructor's exception.
 * @throw rethrows destructor exception.
 * @throw pmem::transaction_free_error when freeing old underlying array failed.
 */
template <typename T>
template <typename InputIt>
void
vector<T>::internal_insert(size_type idx, InputIt first, InputIt last)
{
	assert(pmemobj_tx_stage() == TX_STAGE_WORK);

	auto count = static_cast<size_type>(std::distance(first, last));

	if (_capacity >= size() + count) {
		pointer dest = _data.get() +
			static_cast<difference_type>(size() + count);
		pointer begin = _data.get() + static_cast<difference_type>(idx);
		pointer end =
			_data.get() + static_cast<difference_type>(size());

		add_data_to_tx(idx, size() - idx + count);

		/* Make a gap for new elements */
		move_elements_backward(begin, end, dest);

		/* Construct new elements in the gap */
		construct_or_assign(idx, first, last);
	} else {
		/*
		 * XXX: future optimization: we don't have to snapshot data
		 * which we will copy (only snapshot for move)
		 */
		add_data_to_tx(0, _size);

		auto old_data = _data;
		auto old_size = _size;
		pointer old_begin = _data.get();
		pointer old_mid =
			_data.get() + static_cast<difference_type>(idx);
		pointer old_end =
			_data.get() + static_cast<difference_type>(size());

		_data = nullptr;
		_size = _capacity = 0;

		alloc(get_recommended_capacity(old_size + count));

		/* Move range before the idx to new array */
		construct_at_end(std::make_move_iterator(old_begin),
				 std::make_move_iterator(old_mid));

		/* Insert (first, last) range to the new array */
		construct_at_end(first, last);

		/* Move remaining element to the new array */
		construct_at_end(std::make_move_iterator(old_mid),
				 std::make_move_iterator(old_end));

		/* destroy and free old data */
		for (size_type i = 0; i < old_size; ++i)
			detail::destroy<value_type>(
				old_data[static_cast<difference_type>(i)]);
		if (pmemobj_tx_free(old_data.raw()) != 0)
			throw detail::exception_with_errormsg<
				pmem::transaction_free_error>(
				"failed to delete persistent memory object");
	}
}

/**
 * Private helper function. Must be called during transaction. Allocates new
 * memory for capacity_new number of elements and copies or moves old elements
 * to new memory area. If the current size is greater than capacity_new, the
 * container is reduced to its first capacity_new elements. If was never
 * allocated behaves as an alloc call.
 *
 * @param[in] capacity_new new capacity.
 *
 * @pre must be called in transaction scope.
 *
 * @post capacity() == capacity_new
 *
 * @throw pmem::transaction_error when snapshotting failed.
 * @throw rethrows constructor's exception.
 * @throw rethrows destructor exception.
 * @throw pmem::transaction_free_error when freeing old underlying array failed.
 */
template <typename T>
void
vector<T>::realloc(size_type capacity_new)
{
	assert(pmemobj_tx_stage() == TX_STAGE_WORK);

	/*
	 * If _data == nullptr this object has never allocated any memory
	 * so we need to behave as alloc instead.
	 */
	if (_data == nullptr)
		return alloc(capacity_new);

	/*
	 * XXX: future optimization: we don't have to snapshot data
	 * which we will not overwrite
	 */
	add_data_to_tx(0, _size);

	auto old_data = _data;
	auto old_size = _size;
	pointer old_begin = _data.get();
	pointer old_end = capacity_new < _size
		? &_data[static_cast<difference_type>(capacity_new)]
		: &_data[static_cast<difference_type>(size())];

	_data = nullptr;
	_size = _capacity = 0;

	alloc(capacity_new);

	construct_at_end(std::make_move_iterator(old_begin),
			 std::make_move_iterator(old_end));

	/* destroy and free old data */
	for (size_type i = 0; i < old_size; ++i)
		detail::destroy<value_type>(
			old_data[static_cast<difference_type>(i)]);
	if (pmemobj_tx_free(old_data.raw()) != 0)
		throw detail::exception_with_errormsg<
			pmem::transaction_free_error>(
			"failed to delete persistent memory object");
}

/**
 * Private helper function. Returns recommended capacity for at least at_least
 * elements.
 *
 * @return recommended new capacity.
 */
template <typename T>
typename vector<T>::size_type
vector<T>::get_recommended_capacity(size_type at_least) const
{
	return detail::next_pow_2(at_least);
}

/**
 * Private helper function. Must be called during transaction. Destroys
 * elements in underlying array beginning from position size_new.
 *
 * @param[in] size_new new size
 *
 * @pre must be called in transaction scope.
 * @pre if initialized, range [begin(), end()) must be snapshotted in current
 * transaction.
 * @pre size_new <= size()
 *
 * @post size() == size_new
 *
 * @throw pmem::transaction_error when snapshotting failed.
 * @throw rethrows destructor exception.
 */
template <typename T>
void
vector<T>::shrink(size_type size_new)
{
	assert(pmemobj_tx_stage() == TX_STAGE_WORK);
	assert(size_new <= _size);

	if (!std::is_trivially_destructible<T>::value)
		add_data_to_tx(size_new, _size - size_new);

	for (size_type i = size_new; i < _size; ++i)
		detail::destroy<value_type>(
			_data[static_cast<difference_type>(i)]);
	_size = size_new;
}

/**
 * Private helper function. Takes a “snapshot” of data in range
 * [&_data[idx_first], &_data[idx_first + num])
 *
 * @param[in] idx_first first index.
 * @param[in] num number of elements to snapshot.
 *
 * @throw pmem::transaction_error when snapshotting failed.
 */
template <typename T>
void
vector<T>::add_data_to_tx(size_type idx_first, size_type num)
{
	assert(idx_first + num <= capacity());

#if LIBPMEMOBJ_CPP_VG_MEMCHECK_ENABLED
	/* Make sure that only data allocated by this vector is accessed */
	assert(VALGRIND_CHECK_MEM_IS_ADDRESSABLE(_data.get() + idx_first,
						 num * sizeof(T)) == 0);
#endif

	auto initialized_num = size() - idx_first;

	/* Snapshot elements in range [idx_first,size()) */
	detail::conditional_add_to_tx(_data.get() + idx_first,
				      (std::min)(initialized_num, num),
				      POBJ_XADD_ASSUME_INITIALIZED);

	if (num > initialized_num) {
		/* Elements after size() do not have to be snapshotted */
		detail::conditional_add_to_tx(_data.get() + size(),
					      num - initialized_num,
					      POBJ_XADD_NO_SNAPSHOT);
	}
}

/**
 * Comparison operator. Compares the contents of two containers.
 *
 * Checks if containers have the same number of elements and each element in lhs
 * is equal to element in rhs at the same position.
 *
 * @param[in] lhs first vector of type pmem::obj::vector<T>
 * @param[in] rhs second vector of type pmem::obj::vector<T>
 *
 * @return true if contents of the containers are equal, false otherwise
 * @relates vector
 */
template <typename T>
bool
operator==(const vector<T> &lhs, const vector<T> &rhs)
{
	return lhs.size() == rhs.size() &&
		std::equal(lhs.begin(), lhs.end(), rhs.begin());
}

/**
 * Comparison operator. Compares the contents of two containers.
 *
 * Checks if containers have the same number of elements and each element in lhs
 * is equal to element in rhs at the same position.
 *
 * @param[in] lhs first vector of type pmem::obj::vector<T>
 * @param[in] rhs second vector of type pmem::obj::vector<T>
 *
 * @return true if contents of the containers are not equal, false otherwise
 * @relates vector
 */
template <typename T>
bool
operator!=(const vector<T> &lhs, const vector<T> &rhs)
{
	return !(lhs == rhs);
}

/**
 * Comparison operator. Compares the contents of two containers
 * lexicographically.
 *
 * @param[in] lhs first vector of type pmem::obj::vector<T>
 * @param[in] rhs second vector of type pmem::obj::vector<T>
 *
 * @return true if contents of lhs are lexicographically less than contents of
 * rhs, false otherwise
 * @relates vector
 */
template <typename T>
bool
operator<(const vector<T> &lhs, const vector<T> &rhs)
{
	return std::lexicographical_compare(lhs.begin(), lhs.end(), rhs.begin(),
					    rhs.end());
}

/**
 * Comparison operator. Compares the contents of two containers
 * lexicographically.
 *
 * @param[in] lhs first vector of type pmem::obj::vector<T>
 * @param[in] rhs second vector of type pmem::obj::vector<T>
 *
 * @return true if contents of lhs are lexicographically lesser than or equal to
 * contents of rhs, false otherwise
 * @relates vector
 */
template <typename T>
bool
operator<=(const vector<T> &lhs, const vector<T> &rhs)
{
	return !(rhs < lhs);
}

/**
 * Comparison operator. Compares the contents of two containers
 * lexicographically.
 *
 * @param[in] lhs first vector of type pmem::obj::vector<T>
 * @param[in] rhs second vector of type pmem::obj::vector<T>
 *
 * @return true if contents of lhs are lexicographically greater than contents
 * of rhs, false otherwise
 * @relates vector
 */

template <typename T>
bool
operator>(const vector<T> &lhs, const vector<T> &rhs)
{
	return rhs < lhs;
}

/**
 * Comparison operator. Compares the contents of two containers
 * lexicographically.
 *
 * @param[in] lhs first vector of type pmem::obj::vector<T>
 * @param[in] rhs second vector of type pmem::obj::vector<T>
 *
 * @return true if contents of lhs are lexicographically greater than or equal
 * to contents of rhs, false otherwise
 * @relates vector
 */
template <typename T>
bool
operator>=(const vector<T> &lhs, const vector<T> &rhs)
{
	return !(lhs < rhs);
}

/**
 * Comparison operator. Compares the contents of two containers.
 *
 * Checks if containers have the same number of elements and each element in lhs
 * is equal to element in rhs at the same position.
 *
 * @param[in] lhs first vector of type pmem::obj::vector<T>
 * @param[in] rhs second vector of type std::vector<T>
 *
 * @return true if contents of the containers are equal, false otherwise
 * @relates vector
 */
template <typename T>
bool
operator==(const vector<T> &lhs, const std::vector<T> &rhs)
{
	return lhs.size() == rhs.size() &&
		std::equal(lhs.begin(), lhs.end(), rhs.begin());
}

/**
 * Comparison operator. Compares the contents of two containers.
 *
 * Checks if containers have the same number of elements and each element in lhs
 * is equal to element in rhs at the same position.
 *
 * @param[in] lhs first vector of type pmem::obj::vector<T>
 * @param[in] rhs second vector of type std::vector<T>
 *
 * @return true if contents of the containers are not equal, false otherwise
 * @relates vector
 */
template <typename T>
bool
operator!=(const vector<T> &lhs, const std::vector<T> &rhs)
{
	return !(lhs == rhs);
}

/**
 * Comparison operator. Compares the contents of two containers
 * lexicographically.
 *
 * @param[in] lhs first vector of type pmem::obj::vector<T>
 * @param[in] rhs second vector of type std::vector<T>
 *
 * @return true if contents of lhs are lexicographically less than contents of
 * rhs, false otherwise
 * @relates vector
 */
template <typename T>
bool
operator<(const vector<T> &lhs, const std::vector<T> &rhs)
{
	return std::lexicographical_compare(lhs.begin(), lhs.end(), rhs.begin(),
					    rhs.end());
}

/**
 * Comparison operator. Compares the contents of two containers
 * lexicographically.
 *
 * @param[in] lhs first vector of type pmem::obj::vector<T>
 * @param[in] rhs second vector of ype std::vector<T>
 *
 * @return true if contents of lhs are lexicographically lesser than or equal to
 * contents of rhs, false otherwise
 * @relates vector
 */
template <typename T>
bool
operator<=(const vector<T> &lhs, const std::vector<T> &rhs)
{
	return !(std::lexicographical_compare(rhs.begin(), rhs.end(),
					      lhs.begin(), lhs.end()));
}

/**
 * Comparison operator. Compares the contents of two containers
 * lexicographically.
 *
 * @param[in] lhs first vector of type pmem::obj::vector<T>
 * @param[in] rhs second vector of type std::vector<T>
 *
 * @return true if contents of lhs are lexicographically greater than contents
 * of rhs, false otherwise
 * @relates vector
 */
template <typename T>
bool
operator>(const vector<T> &lhs, const std::vector<T> &rhs)
{
	return !(lhs <= rhs);
}

/**
 * Comparison operator. Compares the contents of two containers
 * lexicographically.
 *
 * @param[in] lhs first vector of type pmem::obj::vector<T>
 * @param[in] rhs second vector of type std::vector<T>
 *
 * @return true if contents of lhs are lexicographically greater than or equal
 * to contents of rhs, false otherwise
 * @relates vector
 */
template <typename T>
bool
operator>=(const vector<T> &lhs, const std::vector<T> &rhs)
{
	return !(lhs < rhs);
}

/**
 * Comparison operator. Compares the contents of two containers.
 *
 * Checks if containers have the same number of elements and each element in lhs
 * is equal to element in rhs at the same position.
 *
 * @param[in] lhs first vector of type std::vector<T>
 * @param[in] rhs second vector of type pmem::obj::vector<T>
 *
 * @return true if contents of the containers are equal, false otherwise
 * @relates vector
 */
template <typename T>
bool
operator==(const std::vector<T> &lhs, const vector<T> &rhs)
{
	return rhs == lhs;
}

/**
 * Comparison operator. Compares the contents of two containers.
 *
 * Checks if containers have the same number of elements and each element in lhs
 * is equal to element in rhs at the same position.
 *
 * @param[in] lhs first vector of type std::vector<T>
 * @param[in] rhs second vector of type pmem::obj::vector<T>
 *
 * @return true if contents of the containers are not equal, false otherwise
 * @relates vector
 */
template <typename T>
bool
operator!=(const std::vector<T> &lhs, const vector<T> &rhs)
{
	return !(lhs == rhs);
}

/**
 * Comparison operator. Compares the contents of two containers
 * lexicographically.
 *
 * @param[in] lhs first vector of type std::vector<T>
 * @param[in] rhs second vector of type pmem::obj::vector<T>
 *
 * @return true if contents of lhs are lexicographically less than contents of
 * rhs, false otherwise
 * @relates vector
 */
template <typename T>
bool
operator<(const std::vector<T> &lhs, const vector<T> &rhs)
{
	return rhs > lhs;
}

/**
 * Comparison operator. Compares the contents of two containers
 * lexicographically.
 *
 * @param[in] lhs first vector of ype std::vector<T>
 * @param[in] rhs second vector of type pmem::obj::vector<T>
 *
 * @return true if contents of lhs are lexicographically lesser than or equal to
 * contents of rhs, false otherwise
 * @relates vector
 */
template <typename T>
bool
operator<=(const std::vector<T> &lhs, const vector<T> &rhs)
{
	return !(rhs < lhs);
}

/**
 * Comparison operator. Compares the contents of two containers
 * lexicographically.
 *
 * @param[in] lhs first vector of type std::vector<T>
 * @param[in] rhs second vector of type pmem::obj::vector<T>
 *
 * @return true if contents of lhs are lexicographically greater than contents
 * of rhs, false otherwise
 * @relates vector
 */

template <typename T>
bool
operator>(const std::vector<T> &lhs, const vector<T> &rhs)
{
	return rhs < lhs;
}

/**
 * Comparison operator. Compares the contents of two containers
 * lexicographically.
 *
 * @param[in] lhs first vector of type std::vector<T>
 * @param[in] rhs second vector of type pmem::obj::vector<T>
 *
 * @return true if contents of lhs are lexicographically greater than or equal
 * to contents of rhs, false otherwise
 * @relates vector
 */
template <typename T>
bool
operator>=(const std::vector<T> &lhs, const vector<T> &rhs)
{
	return !(lhs < rhs);
}

/**
 * Swaps the contents of lhs and rhs.
 *
 * @param[in] lhs first vector
 * @param[in] rhs second vector
 * @relates vector
 */
template <typename T>
void
swap(vector<T> &lhs, vector<T> &rhs)
{
	lhs.swap(rhs);
}

} /* namespace obj */

} /* namespace pmem */

#endif /* LIBPMEMOBJ_CPP_VECTOR_HPP */
