// Copyright 2019 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// -----------------------------------------------------------------------------
// File: inlined_vector.h
// -----------------------------------------------------------------------------
//
// This header file contains the declaration and definition of an "inlined
// vector" which behaves in an equivalent fashion to a `std::vector`, except
// that storage for small sequences of the vector are provided inline without
// requiring any heap allocation.
//
// An `absl::InlinedVector<T, N>` specifies the default capacity `N` as one of
// its template parameters. Instances where `size() <= N` hold contained
// elements in inline space. Typically `N` is very small so that sequences that
// are expected to be short do not require allocations.
//
// An `absl::InlinedVector` does not usually require a specific allocator. If
// the inlined vector grows beyond its initial constraints, it will need to
// allocate (as any normal `std::vector` would). This is usually performed with
// the default allocator (defined as `std::allocator<T>`). Optionally, a custom
// allocator type may be specified as `A` in `absl::InlinedVector<T, N, A>`.

#ifndef ABSL_CONTAINER_INLINED_VECTOR_H_
#define ABSL_CONTAINER_INLINED_VECTOR_H_

#include <algorithm>
#include <cstddef>
#include <cstdlib>
#include <cstring>
#include <initializer_list>
#include <iterator>
#include <memory>
#include <type_traits>
#include <utility>

#include "third_party/abseil-cpp/absl/algorithm/algorithm.h"
#include "third_party/abseil-cpp/absl/base/attributes.h"
#include "third_party/abseil-cpp/absl/base/gdb_scripting.h"  // absl:google3-only(TODO(b/35343588))
#include "third_party/abseil-cpp/absl/base/internal/throw_delegate.h"
#include "third_party/abseil-cpp/absl/base/macros.h"
#include "third_party/abseil-cpp/absl/base/optimization.h"
#include "third_party/abseil-cpp/absl/base/port.h"
#include "third_party/abseil-cpp/absl/container/internal/inlined_vector.h"
#include "third_party/abseil-cpp/absl/memory/memory.h"
#include "third_party/abseil-cpp/absl/meta/type_traits.h"

// absl:google3-begin(Don't ship pretty-printers until at least Python release)
DEFINE_GDB_AUTO_SCRIPT("devtools/gdb/component/core/inlined_vector.py")
// absl:google3-end

struct internal_b197379895_workaround;  // absl:google3-only(TODO(b/197379895))

namespace absl {
    ABSL_NAMESPACE_BEGIN
// -----------------------------------------------------------------------------
// InlinedVector
// -----------------------------------------------------------------------------
//
// An `absl::InlinedVector` is designed to be a drop-in replacement for
// `std::vector` for use cases where the vector's size is sufficiently small
// that it can be inlined. If the inlined vector does grow beyond its estimated
// capacity, it will trigger an initial allocation on the heap, and will behave
// as a `std::vector`. The API of the `absl::InlinedVector` within this file is
// designed to cover the same API footprint as covered by `std::vector`.
    template <typename T, size_t N, typename A = std::allocator<T>>
    class ABSL_ATTRIBUTE_WARN_UNUSED InlinedVector {
            static_assert(N > 0, "`absl::InlinedVector` requires an inlined capacity.");

            using Storage = inlined_vector_internal::Storage<T, N, A>;

            template <typename TheA>
            using AllocatorTraits = inlined_vector_internal::AllocatorTraits<TheA>;
            template <typename TheA>
            using MoveIterator = inlined_vector_internal::MoveIterator<TheA>;
            template <typename TheA>
            using IsMoveAssignOk = inlined_vector_internal::IsMoveAssignOk<TheA>;

            template <typename TheA, typename Iterator>
            using IteratorValueAdapter =
            inlined_vector_internal::IteratorValueAdapter<TheA, Iterator>;
            template <typename TheA>
            using CopyValueAdapter = inlined_vector_internal::CopyValueAdapter<TheA>;
            template <typename TheA>
            using DefaultValueAdapter =
            inlined_vector_internal::DefaultValueAdapter<TheA>;

            template <typename Iterator>
            using EnableIfAtLeastForwardIterator = absl::enable_if_t<
            inlined_vector_internal::IsAtLeastForwardIterator<Iterator>::value, int>;
            template <typename Iterator>
            using DisableIfAtLeastForwardIterator = absl::enable_if_t<
            !inlined_vector_internal::IsAtLeastForwardIterator<Iterator>::value, int>;

            using MemcpyPolicy = typename Storage::MemcpyPolicy;
            using ElementwiseAssignPolicy = typename Storage::ElementwiseAssignPolicy;
            using ElementwiseConstructPolicy =
            typename Storage::ElementwiseConstructPolicy;
            using MoveAssignmentPolicy = typename Storage::MoveAssignmentPolicy;

            public:
            using allocator_type = A;
            using value_type = inlined_vector_internal::ValueType<A>;
            using pointer = inlined_vector_internal::Pointer<A>;
            using const_pointer = inlined_vector_internal::ConstPointer<A>;
            using size_type = inlined_vector_internal::SizeType<A>;
            using difference_type = inlined_vector_internal::DifferenceType<A>;
            using reference = inlined_vector_internal::Reference<A>;
            using const_reference = inlined_vector_internal::ConstReference<A>;
            using iterator = inlined_vector_internal::Iterator<A>;
            using const_iterator = inlined_vector_internal::ConstIterator<A>;
            using reverse_iterator = inlined_vector_internal::ReverseIterator<A>;
            using const_reverse_iterator =
            inlined_vector_internal::ConstReverseIterator<A>;

            // ---------------------------------------------------------------------------
            // InlinedVector Constructors and Destructor
            // ---------------------------------------------------------------------------

            // Creates an empty inlined vector with a value-initialized allocator.
            InlinedVector() noexcept(noexcept(allocator_type())) : storage_() {}

            // Creates an empty inlined vector with a copy of `allocator`.
            explicit InlinedVector(const allocator_type& allocator) noexcept
            : storage_(allocator) {}

            // Creates an inlined vector with `n` copies of `value_type()`.
            explicit InlinedVector(size_type n,
            const allocator_type& allocator = allocator_type())
            : storage_(allocator) {
                storage_.Initialize(DefaultValueAdapter<A>(), n);
            }

            // Creates an inlined vector with `n` copies of `v`.
            InlinedVector(size_type n, const_reference v,
            const allocator_type& allocator = allocator_type())
            : storage_(allocator) {
                storage_.Initialize(CopyValueAdapter<A>(std::addressof(v)), n);
            }

            // Creates an inlined vector with copies of the elements of `list`.
            InlinedVector(std::initializer_list<value_type> list,
            const allocator_type& allocator = allocator_type())
            : InlinedVector(list.begin(), list.end(), allocator) {}

            // Creates an inlined vector with elements constructed from the provided
            // forward iterator range [`first`, `last`).
            //
            // NOTE: the `enable_if` prevents ambiguous interpretation between a call to
            // this constructor with two integral arguments and a call to the above
            // `InlinedVector(size_type, const_reference)` constructor.
            template <typename ForwardIterator,
            EnableIfAtLeastForwardIterator<ForwardIterator> = 0>
            InlinedVector(ForwardIterator first, ForwardIterator last,
            const allocator_type& allocator = allocator_type())
            : storage_(allocator) {
                storage_.Initialize(IteratorValueAdapter<A, ForwardIterator>(first),
                                    static_cast<size_t>(std::distance(first, last)));
            }

            // Creates an inlined vector with elements constructed from the provided input
            // iterator range [`first`, `last`).
            template <typename InputIterator,
            DisableIfAtLeastForwardIterator<InputIterator> = 0>
            InlinedVector(InputIterator first, InputIterator last,
            const allocator_type& allocator = allocator_type())
            : storage_(allocator) {
                std::copy(first, last, std::back_inserter(*this));
            }

            // Creates an inlined vector by copying the contents of `other` using
            // `other`'s allocator.
            InlinedVector(const InlinedVector& other)
            : InlinedVector(other, other.storage_.GetAllocator()) {}

            // Creates an inlined vector by copying the contents of `other` using the
            // provided `allocator`.
            InlinedVector(const InlinedVector& other, const allocator_type& allocator)
            : storage_(allocator) {
                // Fast path: if the other vector is empty, there's nothing for us to do.
                if (other.empty()) {
                    return;
                }

                // Fast path: if the value type is trivially copy constructible, we know the
                // allocator doesn't do anything fancy, and there is nothing on the heap
                // then we know it is legal for us to simply memcpy the other vector's
                // inlined bytes to form our copy of its elements.
                if (absl::is_trivially_copy_constructible<value_type>::value &&
                    std::is_same<A, std::allocator<value_type>>::value &&
                                    !other.storage_.GetIsAllocated()) {
                    storage_.MemcpyFrom(other.storage_);
                    return;
                }

                storage_.InitFrom(other.storage_);
            }

            // Creates an inlined vector by moving in the contents of `other` without
            // allocating. If `other` contains allocated memory, the newly-created inlined
            // vector will take ownership of that memory. However, if `other` does not
            // contain allocated memory, the newly-created inlined vector will perform
            // element-wise move construction of the contents of `other`.
            //
            // NOTE: since no allocation is performed for the inlined vector in either
            // case, the `noexcept(...)` specification depends on whether moving the
            // underlying objects can throw. It is assumed assumed that...
            //  a) move constructors should only throw due to allocation failure.
            //  b) if `value_type`'s move constructor allocates, it uses the same
            //     allocation function as the inlined vector's allocator.
            // Thus, the move constructor is non-throwing if the allocator is non-throwing
            // or `value_type`'s move constructor is specified as `noexcept`.
            InlinedVector(InlinedVector&& other) noexcept(
            absl::allocator_is_nothrow<allocator_type>::value ||
            std::is_nothrow_move_constructible<value_type>::value)
            : storage_(other.storage_.GetAllocator()) {
                // Fast path: if the value type can be trivially relocated (i.e. moved from
                // and destroyed), and we know the allocator doesn't do anything fancy, then
                // it's safe for us to simply adopt the contents of the storage for `other`
                // and remove its own reference to them. It's as if we had individually
                // move-constructed each value and then destroyed the original.
                if (absl::is_trivially_relocatable<value_type>::value &&
                    std::is_same<A, std::allocator<value_type>>::value) {
                    storage_.MemcpyFrom(other.storage_);
                    other.storage_.SetInlinedSize(0);
                    return;
                }

                // Fast path: if the other vector is on the heap, we can simply take over
                // its allocation.
                if (other.storage_.GetIsAllocated()) {
                    storage_.SetAllocation({other.storage_.GetAllocatedData(),
                                            other.storage_.GetAllocatedCapacity()});
                    storage_.SetAllocatedSize(other.storage_.GetSize());

                    other.storage_.SetInlinedSize(0);
                    return;
                }

                // Otherwise we must move each element individually.
                IteratorValueAdapter<A, MoveIterator<A>> other_values(
                        MoveIterator<A>(other.storage_.GetInlinedData()));

                inlined_vector_internal::ConstructElements<A>(
                        storage_.GetAllocator(), storage_.GetInlinedData(), other_values,
                        other.storage_.GetSize());

                storage_.SetInlinedSize(other.storage_.GetSize());
            }

            // Creates an inlined vector by moving in the contents of `other` with a copy
            // of `allocator`.
            //
            // NOTE: if `other`'s allocator is not equal to `allocator`, even if `other`
            // contains allocated memory, this move constructor will still allocate. Since
            // allocation is performed, this constructor can only be `noexcept` if the
            // specified allocator is also `noexcept`.
            InlinedVector(
            InlinedVector&& other,
            const allocator_type&
            allocator) noexcept(absl::allocator_is_nothrow<allocator_type>::value)
            : storage_(allocator) {
                // Fast path: if the value type can be trivially relocated (i.e. moved from
                // and destroyed), and we know the allocator doesn't do anything fancy, then
                // it's safe for us to simply adopt the contents of the storage for `other`
                // and remove its own reference to them. It's as if we had individually
                // move-constructed each value and then destroyed the original.
                if (absl::is_trivially_relocatable<value_type>::value &&
                    std::is_same<A, std::allocator<value_type>>::value) {
                    storage_.MemcpyFrom(other.storage_);
                    other.storage_.SetInlinedSize(0);
                    return;
                }

                // Fast path: if the other vector is on the heap and shared the same
                // allocator, we can simply take over its allocation.
                if ((storage_.GetAllocator() == other.storage_.GetAllocator()) &&
                    other.storage_.GetIsAllocated()) {
                    storage_.SetAllocation({other.storage_.GetAllocatedData(),
                                            other.storage_.GetAllocatedCapacity()});
                    storage_.SetAllocatedSize(other.storage_.GetSize());

                    other.storage_.SetInlinedSize(0);
                    return;
                }

                // Otherwise we must move each element individually.
                storage_.Initialize(
                        IteratorValueAdapter<A, MoveIterator<A>>(MoveIterator<A>(other.data())),
                        other.size());
            }

            ~InlinedVector() {}

            // ---------------------------------------------------------------------------
            // InlinedVector Member Accessors
            // ---------------------------------------------------------------------------

            // `InlinedVector::empty()`
            //
            // Returns whether the inlined vector contains no elements.
            bool empty() const noexcept { return !size(); }

            // `InlinedVector::size()`
            //
            // Returns the number of elements in the inlined vector.
            size_type size() const noexcept { return storage_.GetSize(); }

            // `InlinedVector::max_size()`
            //
            // Returns the maximum number of elements the inlined vector can hold.
            size_type max_size() const noexcept {
                // One bit of the size storage is used to indicate whether the inlined
                // vector contains allocated memory. As a result, the maximum size that the
                // inlined vector can express is the minimum of the limit of how many
                // objects we can allocate and std::numeric_limits<size_type>::max() / 2.
                return (std::min)(AllocatorTraits<A>::max_size(storage_.GetAllocator()),
                                  (std::numeric_limits<size_type>::max)() / 2);
            }

            // `InlinedVector::capacity()`
            //
            // Returns the number of elements that could be stored in the inlined vector
            // without requiring a reallocation.
            //
            // NOTE: for most inlined vectors, `capacity()` should be equal to the
            // template parameter `N`. For inlined vectors which exceed this capacity,
            // they will no longer be inlined and `capacity()` will equal the capactity of
            // the allocated memory.
            size_type capacity() const noexcept {
                return storage_.GetIsAllocated() ? storage_.GetAllocatedCapacity()
                                                 : storage_.GetInlinedCapacity();
            }

            // `InlinedVector::data()`
            //
            // Returns a `pointer` to the elements of the inlined vector. This pointer
            // can be used to access and modify the contained elements.
            //
            // NOTE: only elements within [`data()`, `data() + size()`) are valid.
            pointer data() noexcept ABSL_ATTRIBUTE_LIFETIME_BOUND {
                return storage_.GetIsAllocated() ? storage_.GetAllocatedData()
                                                 : storage_.GetInlinedData();
            }

            // Overload of `InlinedVector::data()` that returns a `const_pointer` to the
            // elements of the inlined vector. This pointer can be used to access but not
            // modify the contained elements.
            //
            // NOTE: only elements within [`data()`, `data() + size()`) are valid.
            const_pointer data() const noexcept ABSL_ATTRIBUTE_LIFETIME_BOUND {
                return storage_.GetIsAllocated() ? storage_.GetAllocatedData()
                                                 : storage_.GetInlinedData();
            }

            // `InlinedVector::operator[](...)`
            //
            // Returns a `reference` to the `i`th element of the inlined vector.
            reference operator[](size_type i) ABSL_ATTRIBUTE_LIFETIME_BOUND {
                ABSL_HARDENING_ASSERT(i < size());
                return data()[i];
            }

            // Overload of `InlinedVector::operator[](...)` that returns a
            // `const_reference` to the `i`th element of the inlined vector.
            const_reference operator[](size_type i) const ABSL_ATTRIBUTE_LIFETIME_BOUND {
                ABSL_HARDENING_ASSERT(i < size());
                return data()[i];
            }

            // `InlinedVector::at(...)`
            //
            // Returns a `reference` to the `i`th element of the inlined vector.
            //
            // NOTE: if `i` is not within the required range of `InlinedVector::at(...)`,
            // in both debug and non-debug builds, `std::out_of_range` will be thrown.
            reference at(size_type i) ABSL_ATTRIBUTE_LIFETIME_BOUND {
                if (ABSL_PREDICT_FALSE(i >= size())) {
                    base_internal::ThrowStdOutOfRange(
                            "`InlinedVector::at(size_type)` failed bounds check");
                }
                return data()[i];
            }

            // Overload of `InlinedVector::at(...)` that returns a `const_reference` to
            // the `i`th element of the inlined vector.
            //
            // NOTE: if `i` is not within the required range of `InlinedVector::at(...)`,
            // in both debug and non-debug builds, `std::out_of_range` will be thrown.
            const_reference at(size_type i) const ABSL_ATTRIBUTE_LIFETIME_BOUND {
                if (ABSL_PREDICT_FALSE(i >= size())) {
                    base_internal::ThrowStdOutOfRange(
                            "`InlinedVector::at(size_type) const` failed bounds check");
                }
                return data()[i];
            }

            // `InlinedVector::front()`
            //
            // Returns a `reference` to the first element of the inlined vector.
            reference front() ABSL_ATTRIBUTE_LIFETIME_BOUND {
                ABSL_HARDENING_ASSERT(!empty());
                return data()[0];
            }

            // Overload of `InlinedVector::front()` that returns a `const_reference` to
            // the first element of the inlined vector.
            const_reference front() const ABSL_ATTRIBUTE_LIFETIME_BOUND {
                ABSL_HARDENING_ASSERT(!empty());
                return data()[0];
            }

            // `InlinedVector::back()`
            //
            // Returns a `reference` to the last element of the inlined vector.
            reference back() ABSL_ATTRIBUTE_LIFETIME_BOUND {
                ABSL_HARDENING_ASSERT(!empty());
                return data()[size() - 1];
            }

            // Overload of `InlinedVector::back()` that returns a `const_reference` to the
            // last element of the inlined vector.
            const_reference back() const ABSL_ATTRIBUTE_LIFETIME_BOUND {
                ABSL_HARDENING_ASSERT(!empty());
                return data()[size() - 1];
            }

            // `InlinedVector::begin()`
            //
            // Returns an `iterator` to the beginning of the inlined vector.
            iterator begin() noexcept ABSL_ATTRIBUTE_LIFETIME_BOUND { return data(); }

            // Overload of `InlinedVector::begin()` that returns a `const_iterator` to
            // the beginning of the inlined vector.
            const_iterator begin() const noexcept ABSL_ATTRIBUTE_LIFETIME_BOUND {
                return data();
            }

            // `InlinedVector::end()`
            //
            // Returns an `iterator` to the end of the inlined vector.
            iterator end() noexcept ABSL_ATTRIBUTE_LIFETIME_BOUND {
                return data() + size();
            }

            // Overload of `InlinedVector::end()` that returns a `const_iterator` to the
            // end of the inlined vector.
            const_iterator end() const noexcept ABSL_ATTRIBUTE_LIFETIME_BOUND {
                return data() + size();
            }

            // `InlinedVector::cbegin()`
            //
            // Returns a `const_iterator` to the beginning of the inlined vector.
            const_iterator cbegin() const noexcept ABSL_ATTRIBUTE_LIFETIME_BOUND {
                return begin();
            }

            // `InlinedVector::cend()`
            //
            // Returns a `const_iterator` to the end of the inlined vector.
            const_iterator cend() const noexcept ABSL_ATTRIBUTE_LIFETIME_BOUND {
                return end();
            }

            // `InlinedVector::rbegin()`
            //
            // Returns a `reverse_iterator` from the end of the inlined vector.
            reverse_iterator rbegin() noexcept ABSL_ATTRIBUTE_LIFETIME_BOUND {
                return reverse_iterator(end());
            }

            // Overload of `InlinedVector::rbegin()` that returns a
            // `const_reverse_iterator` from the end of the inlined vector.
            const_reverse_iterator rbegin() const noexcept ABSL_ATTRIBUTE_LIFETIME_BOUND {
                return const_reverse_iterator(end());
            }

            // `InlinedVector::rend()`
            //
            // Returns a `reverse_iterator` from the beginning of the inlined vector.
            reverse_iterator rend() noexcept ABSL_ATTRIBUTE_LIFETIME_BOUND {
                return reverse_iterator(begin());
            }

            // Overload of `InlinedVector::rend()` that returns a `const_reverse_iterator`
            // from the beginning of the inlined vector.
            const_reverse_iterator rend() const noexcept ABSL_ATTRIBUTE_LIFETIME_BOUND {
                return const_reverse_iterator(begin());
            }

            // `InlinedVector::crbegin()`
            //
            // Returns a `const_reverse_iterator` from the end of the inlined vector.
            const_reverse_iterator crbegin() const noexcept
            ABSL_ATTRIBUTE_LIFETIME_BOUND {
                return rbegin();
            }

            // `InlinedVector::crend()`
            //
            // Returns a `const_reverse_iterator` from the beginning of the inlined
            // vector.
            const_reverse_iterator crend() const noexcept ABSL_ATTRIBUTE_LIFETIME_BOUND {
                return rend();
            }

            // `InlinedVector::get_allocator()`
            //
            // Returns a copy of the inlined vector's allocator.
            allocator_type get_allocator() const { return storage_.GetAllocator(); }

            // ---------------------------------------------------------------------------
            // InlinedVector Member Mutators
            // ---------------------------------------------------------------------------

            // `InlinedVector::operator=(...)`
            //
            // Replaces the elements of the inlined vector with copies of the elements of
            // `list`.
            InlinedVector& operator=(std::initializer_list<value_type> list) {
                assign(list.begin(), list.end());

                return *this;
            }

            // Overload of `InlinedVector::operator=(...)` that replaces the elements of
            // the inlined vector with copies of the elements of `other`.
            InlinedVector& operator=(const InlinedVector& other) {
                if (ABSL_PREDICT_TRUE(this != std::addressof(other))) {
                    const_pointer other_data = other.data();
                    assign(other_data, other_data + other.size());
                }

                return *this;
            }

            // Overload of `InlinedVector::operator=(...)` that moves the elements of
            // `other` into the inlined vector.
            //
            // NOTE: as a result of calling this overload, `other` is left in a valid but
            // unspecified state.
            InlinedVector& operator=(InlinedVector&& other) {
                if (ABSL_PREDICT_TRUE(this != std::addressof(other))) {
                    MoveAssignment(MoveAssignmentPolicy{}, std::move(other));
                }

                return *this;
            }

            // `InlinedVector::assign(...)`
            //
            // Replaces the contents of the inlined vector with `n` copies of `v`.
            void assign(size_type n, const_reference v) {
                storage_.Assign(CopyValueAdapter<A>(std::addressof(v)), n);
            }

            // Overload of `InlinedVector::assign(...)` that replaces the contents of the
            // inlined vector with copies of the elements of `list`.
            void assign(std::initializer_list<value_type> list) {
                assign(list.begin(), list.end());
            }

            // Overload of `InlinedVector::assign(...)` to replace the contents of the
            // inlined vector with the range [`first`, `last`).
            //
            // NOTE: this overload is for iterators that are "forward" category or better.
            template <typename ForwardIterator,
            EnableIfAtLeastForwardIterator<ForwardIterator> = 0>
            void assign(ForwardIterator first, ForwardIterator last) {
                storage_.Assign(IteratorValueAdapter<A, ForwardIterator>(first),
                                static_cast<size_t>(std::distance(first, last)));
            }

            // Overload of `InlinedVector::assign(...)` to replace the contents of the
            // inlined vector with the range [`first`, `last`).
            //
            // NOTE: this overload is for iterators that are "input" category.
            template <typename InputIterator,
            DisableIfAtLeastForwardIterator<InputIterator> = 0>
            void assign(InputIterator first, InputIterator last) {
                size_type i = 0;
                for (; i < size() && first != last; ++i, static_cast<void>(++first)) {
                    data()[i] = *first;
                }

                erase(data() + i, data() + size());
                std::copy(first, last, std::back_inserter(*this));
            }

            // `InlinedVector::resize(...)`
            //
            // Resizes the inlined vector to contain `n` elements.
            //
            // NOTE: If `n` is smaller than `size()`, extra elements are destroyed. If `n`
            // is larger than `size()`, new elements are value-initialized.
            void resize(size_type n) {
                ABSL_HARDENING_ASSERT(n <= max_size());
                storage_.Resize(DefaultValueAdapter<A>(), n);
            }

            // Overload of `InlinedVector::resize(...)` that resizes the inlined vector to
            // contain `n` elements.
            //
            // NOTE: if `n` is smaller than `size()`, extra elements are destroyed. If `n`
            // is larger than `size()`, new elements are copied-constructed from `v`.
            void resize(size_type n, const_reference v) {
                ABSL_HARDENING_ASSERT(n <= max_size());
                storage_.Resize(CopyValueAdapter<A>(std::addressof(v)), n);
            }

            // `InlinedVector::insert(...)`
            //
            // Inserts a copy of `v` at `pos`, returning an `iterator` to the newly
            // inserted element.
            iterator insert(const_iterator pos,
            const_reference v) ABSL_ATTRIBUTE_LIFETIME_BOUND {
                return emplace(pos, v);
            }

            // Overload of `InlinedVector::insert(...)` that inserts `v` at `pos` using
            // move semantics, returning an `iterator` to the newly inserted element.
            iterator insert(const_iterator pos,
            value_type&& v) ABSL_ATTRIBUTE_LIFETIME_BOUND {
                return emplace(pos, std::move(v));
            }

            // Overload of `InlinedVector::insert(...)` that inserts `n` contiguous copies
            // of `v` starting at `pos`, returning an `iterator` pointing to the first of
            // the newly inserted elements.
            iterator insert(const_iterator pos, size_type n,
            const_reference v) ABSL_ATTRIBUTE_LIFETIME_BOUND {
                ABSL_HARDENING_ASSERT(pos >= begin());
                ABSL_HARDENING_ASSERT(pos <= end());

                if (ABSL_PREDICT_TRUE(n != 0)) {
                    value_type dealias = v;
                    // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102329#c2
                    // It appears that GCC thinks that since `pos` is a const pointer and may
                    // point to uninitialized memory at this point, a warning should be
                    // issued. But `pos` is actually only used to compute an array index to
                    // write to.
#if !defined(__clang__) && defined(__GNUC__)
                    #pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
#endif
                    return storage_.Insert(pos, CopyValueAdapter<A>(std::addressof(dealias)),
                                           n);
#if !defined(__clang__) && defined(__GNUC__)
#pragma GCC diagnostic pop
#endif
                } else {
                    return const_cast<iterator>(pos);
                }
            }

            // Overload of `InlinedVector::insert(...)` that inserts copies of the
            // elements of `list` starting at `pos`, returning an `iterator` pointing to
            // the first of the newly inserted elements.
            iterator insert(const_iterator pos, std::initializer_list<value_type> list)
            ABSL_ATTRIBUTE_LIFETIME_BOUND {
                return insert(pos, list.begin(), list.end());
            }

            // Overload of `InlinedVector::insert(...)` that inserts the range [`first`,
            // `last`) starting at `pos`, returning an `iterator` pointing to the first
            // of the newly inserted elements.
            //
            // NOTE: this overload is for iterators that are "forward" category or better.
            template <typename ForwardIterator,
            EnableIfAtLeastForwardIterator<ForwardIterator> = 0>
            iterator insert(const_iterator pos, ForwardIterator first,
            ForwardIterator last) ABSL_ATTRIBUTE_LIFETIME_BOUND {
                ABSL_HARDENING_ASSERT(pos >= begin());
                ABSL_HARDENING_ASSERT(pos <= end());

                if (ABSL_PREDICT_TRUE(first != last)) {
                    return storage_.Insert(
                            pos, IteratorValueAdapter<A, ForwardIterator>(first),
                            static_cast<size_type>(std::distance(first, last)));
                } else {
                    return const_cast<iterator>(pos);
                }
            }

            // Overload of `InlinedVector::insert(...)` that inserts the range [`first`,
            // `last`) starting at `pos`, returning an `iterator` pointing to the first
            // of the newly inserted elements.
            //
            // NOTE: this overload is for iterators that are "input" category.
            template <typename InputIterator,
            DisableIfAtLeastForwardIterator<InputIterator> = 0>
            iterator insert(const_iterator pos, InputIterator first,
            InputIterator last) ABSL_ATTRIBUTE_LIFETIME_BOUND {
                ABSL_HARDENING_ASSERT(pos >= begin());
                ABSL_HARDENING_ASSERT(pos <= end());

                size_type index = static_cast<size_type>(std::distance(cbegin(), pos));
                for (size_type i = index; first != last; ++i, static_cast<void>(++first)) {
                    insert(data() + i, *first);
                }

                return iterator(data() + index);
            }

            // `InlinedVector::emplace(...)`
            //
            // Constructs and inserts an element using `args...` in the inlined vector at
            // `pos`, returning an `iterator` pointing to the newly emplaced element.
            template <typename... Args>
            iterator emplace(const_iterator pos,
            Args&&... args) ABSL_ATTRIBUTE_LIFETIME_BOUND {
                ABSL_HARDENING_ASSERT(pos >= begin());
                ABSL_HARDENING_ASSERT(pos <= end());

                value_type dealias(std::forward<Args>(args)...);
                // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102329#c2
                // It appears that GCC thinks that since `pos` is a const pointer and may
                // point to uninitialized memory at this point, a warning should be
                // issued. But `pos` is actually only used to compute an array index to
                // write to.
#if !defined(__clang__) && defined(__GNUC__)
                #pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
#endif
                return storage_.Insert(pos,
                                       IteratorValueAdapter<A, MoveIterator<A>>(
                                MoveIterator<A>(std::addressof(dealias))),
                                       1);
#if !defined(__clang__) && defined(__GNUC__)
#pragma GCC diagnostic pop
#endif
            }

            // `InlinedVector::emplace_back(...)`
            //
            // Constructs and inserts an element using `args...` in the inlined vector at
            // `end()`, returning a `reference` to the newly emplaced element.
            template <typename... Args>
            reference emplace_back(Args&&... args) ABSL_ATTRIBUTE_LIFETIME_BOUND {
                return storage_.EmplaceBack(std::forward<Args>(args)...);
            }

            // `InlinedVector::push_back(...)`
            //
            // Inserts a copy of `v` in the inlined vector at `end()`.
            void push_back(const_reference v) { static_cast<void>(emplace_back(v)); }

            // Overload of `InlinedVector::push_back(...)` for inserting `v` at `end()`
            // using move semantics.
            void push_back(value_type&& v) {
                static_cast<void>(emplace_back(std::move(v)));
            }

            // `InlinedVector::pop_back()`
            //
            // Destroys the element at `back()`, reducing the size by `1`.
            void pop_back() noexcept {
                ABSL_HARDENING_ASSERT(!empty());

                AllocatorTraits<A>::destroy(storage_.GetAllocator(), data() + (size() - 1));
                storage_.SubtractSize(1);
            }

            // `InlinedVector::erase(...)`
            //
            // Erases the element at `pos`, returning an `iterator` pointing to where the
            // erased element was located.
            //
            // NOTE: may return `end()`, which is not dereferenceable.
            iterator erase(const_iterator pos) ABSL_ATTRIBUTE_LIFETIME_BOUND {
                ABSL_HARDENING_ASSERT(pos >= begin());
                ABSL_HARDENING_ASSERT(pos < end());

                // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102329#c2
                // It appears that GCC thinks that since `pos` is a const pointer and may
                // point to uninitialized memory at this point, a warning should be
                // issued. But `pos` is actually only used to compute an array index to
                // write to.
#if !defined(__clang__) && defined(__GNUC__)
                #pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
#pragma GCC diagnostic ignored "-Wuninitialized"
#endif
                return storage_.Erase(pos, pos + 1);
#if !defined(__clang__) && defined(__GNUC__)
#pragma GCC diagnostic pop
#endif
            }

            // Overload of `InlinedVector::erase(...)` that erases every element in the
            // range [`from`, `to`), returning an `iterator` pointing to where the first
            // erased element was located.
            //
            // NOTE: may return `end()`, which is not dereferenceable.
            iterator erase(const_iterator from,
            const_iterator to) ABSL_ATTRIBUTE_LIFETIME_BOUND {
                ABSL_HARDENING_ASSERT(from >= begin());
                ABSL_HARDENING_ASSERT(from <= to);
                ABSL_HARDENING_ASSERT(to <= end());

                if (ABSL_PREDICT_TRUE(from != to)) {
                    return storage_.Erase(from, to);
                } else {
                    return const_cast<iterator>(from);
                }
            }

            // `InlinedVector::clear()`
            //
            // Destroys all elements in the inlined vector, setting the size to `0` and
            // deallocating any held memory.
            void clear() noexcept {
                inlined_vector_internal::DestroyAdapter<A>::DestroyElements(
                        storage_.GetAllocator(), data(), size());
                storage_.DeallocateIfAllocated();

                storage_.SetInlinedSize(0);
            }

            // `InlinedVector::reserve(...)`
            //
            // Ensures that there is enough room for at least `n` elements.
            void reserve(size_type n) { storage_.Reserve(n); }

            // `InlinedVector::shrink_to_fit()`
            //
            // Attempts to reduce memory usage by moving elements to (or keeping elements
            // in) the smallest available buffer sufficient for containing `size()`
            // elements.
            //
            // If `size()` is sufficiently small, the elements will be moved into (or kept
            // in) the inlined space.
            void shrink_to_fit() {
                if (storage_.GetIsAllocated()) {
                    storage_.ShrinkToFit();
                }
            }

            // `InlinedVector::swap(...)`
            //
            // Swaps the contents of the inlined vector with `other`.
            void swap(InlinedVector& other) {
                if (ABSL_PREDICT_TRUE(this != std::addressof(other))) {
                    storage_.Swap(std::addressof(other.storage_));
                }
            }

            private:
            template <typename H, typename TheT, size_t TheN, typename TheA>
            friend H AbslHashValue(H h, const absl::InlinedVector<TheT, TheN, TheA>& a);

            void MoveAssignment(MemcpyPolicy, InlinedVector&& other) {
                // Assumption check: we shouldn't be told to use memcpy to implement move
                // assignment unless we have trivially destructible elements and an
                // allocator that does nothing fancy.
                static_assert(absl::is_trivially_destructible<value_type>::value, "");
                static_assert(std::is_same<A, std::allocator<value_type>>::value, "");

                // Throw away our existing heap allocation, if any. There is no need to
                // destroy the existing elements one by one because we know they are
                // trivially destructible.
                storage_.DeallocateIfAllocated();

                // Adopt the other vector's inline elements or heap allocation.
                storage_.MemcpyFrom(other.storage_);
                other.storage_.SetInlinedSize(0);
            }

            // Destroy our existing elements, if any, and adopt the heap-allocated
            // elements of the other vector.
            //
            // REQUIRES: other.storage_.GetIsAllocated()
            void DestroyExistingAndAdopt(InlinedVector&& other) {
                ABSL_HARDENING_ASSERT(other.storage_.GetIsAllocated());

                inlined_vector_internal::DestroyAdapter<A>::DestroyElements(
                        storage_.GetAllocator(), data(), size());
                storage_.DeallocateIfAllocated();

                storage_.MemcpyFrom(other.storage_);
                other.storage_.SetInlinedSize(0);
            }

            void MoveAssignment(ElementwiseAssignPolicy, InlinedVector&& other) {
                // Fast path: if the other vector is on the heap then we don't worry about
                // actually move-assigning each element. Instead we only throw away our own
                // existing elements and adopt the heap allocation of the other vector.
                if (other.storage_.GetIsAllocated()) {
                    DestroyExistingAndAdopt(std::move(other));
                    return;
                }

                storage_.Assign(IteratorValueAdapter<A, MoveIterator<A>>(
                                        MoveIterator<A>(other.storage_.GetInlinedData())),
                                other.size());
            }

            void MoveAssignment(ElementwiseConstructPolicy, InlinedVector&& other) {
                // Fast path: if the other vector is on the heap then we don't worry about
                // actually move-assigning each element. Instead we only throw away our own
                // existing elements and adopt the heap allocation of the other vector.
                if (other.storage_.GetIsAllocated()) {
                    DestroyExistingAndAdopt(std::move(other));
                    return;
                }

                inlined_vector_internal::DestroyAdapter<A>::DestroyElements(
                        storage_.GetAllocator(), data(), size());
                storage_.DeallocateIfAllocated();

                IteratorValueAdapter<A, MoveIterator<A>> other_values(
                        MoveIterator<A>(other.storage_.GetInlinedData()));
                inlined_vector_internal::ConstructElements<A>(
                        storage_.GetAllocator(), storage_.GetInlinedData(), other_values,
                        other.storage_.GetSize());
                storage_.SetInlinedSize(other.storage_.GetSize());
            }

            Storage storage_;
    };

// -----------------------------------------------------------------------------
// InlinedVector Non-Member Functions
// -----------------------------------------------------------------------------

// `swap(...)`
//
// Swaps the contents of two inlined vectors.
    template <typename T, size_t N, typename A>
    void swap(absl::InlinedVector<T, N, A>& a,
              absl::InlinedVector<T, N, A>& b) noexcept(noexcept(a.swap(b))) {
    a.swap(b);
}

// `operator==(...)`
//
// Tests for value-equality of two inlined vectors.
template <typename T, size_t N, typename A>
bool operator==(const absl::InlinedVector<T, N, A>& a,
                const absl::InlinedVector<T, N, A>& b) {
    auto a_data = a.data();
    auto b_data = b.data();
    return std::equal(a_data, a_data + a.size(), b_data, b_data + b.size());
}

// `operator!=(...)`
//
// Tests for value-inequality of two inlined vectors.
template <typename T, size_t N, typename A>
bool operator!=(const absl::InlinedVector<T, N, A>& a,
                const absl::InlinedVector<T, N, A>& b) {
    return !(a == b);
}

// `operator<(...)`
//
// Tests whether the value of an inlined vector is less than the value of
// another inlined vector using a lexicographical comparison algorithm.
template <typename T, size_t N, typename A>
bool operator<(const absl::InlinedVector<T, N, A>& a,
               const absl::InlinedVector<T, N, A>& b) {
    auto a_data = a.data();
    auto b_data = b.data();
    return std::lexicographical_compare(a_data, a_data + a.size(), b_data,
                                        b_data + b.size());
}

// `operator>(...)`
//
// Tests whether the value of an inlined vector is greater than the value of
// another inlined vector using a lexicographical comparison algorithm.
template <typename T, size_t N, typename A>
bool operator>(const absl::InlinedVector<T, N, A>& a,
               const absl::InlinedVector<T, N, A>& b) {
    return b < a;
}

// `operator<=(...)`
//
// Tests whether the value of an inlined vector is less than or equal to the
// value of another inlined vector using a lexicographical comparison algorithm.
template <typename T, size_t N, typename A>
bool operator<=(const absl::InlinedVector<T, N, A>& a,
                const absl::InlinedVector<T, N, A>& b) {
    return !(b < a);
}

// `operator>=(...)`
//
// Tests whether the value of an inlined vector is greater than or equal to the
// value of another inlined vector using a lexicographical comparison algorithm.
template <typename T, size_t N, typename A>
bool operator>=(const absl::InlinedVector<T, N, A>& a,
                const absl::InlinedVector<T, N, A>& b) {
    return !(a < b);
}

// `AbslHashValue(...)`
//
// Provides `absl::Hash` support for `absl::InlinedVector`. It is uncommon to
// call this directly.
// absl:google3-only(See http://go/absl-hash to learn more.)
template <typename H, typename T, size_t N, typename A>
H AbslHashValue(H h, const absl::InlinedVector<T, N, A>& a) {
    auto size = a.size();
    return H::combine(H::combine_contiguous(std::move(h), a.data(), size), size);
}

ABSL_NAMESPACE_END
}  // namespace absl

#endif  // THIRD_PARTY_ABSL_CONTAINER_INLINED_VECTOR_H_