// 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 <cassert>
#include <cstddef>
#include <cstdlib>
#include <cstring>
#include <initializer_list>
#include <iterator>
#include <memory>
#include <type_traits>
#include <utility>
#include "absl/algorithm/algorithm.h"
#include "absl/base/internal/throw_delegate.h"
#include "absl/base/macros.h"
#include "absl/base/optimization.h"
#include "absl/base/port.h"
#include "absl/container/internal/inlined_vector.h"
#include "absl/memory/memory.h"
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 InlinedVector {
static_assert(N > 0, "`absl::InlinedVector` requires an inlined capacity.");
using Storage = inlined_vector_internal::Storage<T, N, A>;
using AllocatorTraits = typename Storage::AllocatorTraits;
using RValueReference = typename Storage::RValueReference;
using MoveIterator = typename Storage::MoveIterator;
using IsMemcpyOk = typename Storage::IsMemcpyOk;
template <typename Iterator>
using IteratorValueAdapter =
typename Storage::template IteratorValueAdapter<Iterator>;
using CopyValueAdapter = typename Storage::CopyValueAdapter;
using DefaultValueAdapter = typename Storage::DefaultValueAdapter;
template <typename Iterator>
using EnableIfAtLeastForwardIterator = absl::enable_if_t<
inlined_vector_internal::IsAtLeastForwardIterator<Iterator>::value>;
template <typename Iterator>
using DisableIfAtLeastForwardIterator = absl::enable_if_t<
!inlined_vector_internal::IsAtLeastForwardIterator<Iterator>::value>;
public:
using allocator_type = typename Storage::allocator_type;
using value_type = typename Storage::value_type;
using pointer = typename Storage::pointer;
using const_pointer = typename Storage::const_pointer;
using size_type = typename Storage::size_type;
using difference_type = typename Storage::difference_type;
using reference = typename Storage::reference;
using const_reference = typename Storage::const_reference;
using iterator = typename Storage::iterator;
using const_iterator = typename Storage::const_iterator;
using reverse_iterator = typename Storage::reverse_iterator;
using const_reverse_iterator = typename Storage::const_reverse_iterator;
// ---------------------------------------------------------------------------
// 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 `alloc`.
explicit InlinedVector(const allocator_type& alloc) noexcept
: storage_(alloc) {}
// Creates an inlined vector with `n` copies of `value_type()`.
explicit InlinedVector(size_type n,
const allocator_type& alloc = allocator_type())
: storage_(alloc) {
storage_.Initialize(DefaultValueAdapter(), n);
}
// Creates an inlined vector with `n` copies of `v`.
InlinedVector(size_type n, const_reference v,
const allocator_type& alloc = allocator_type())
: storage_(alloc) {
storage_.Initialize(CopyValueAdapter(v), n);
}
// Creates an inlined vector with copies of the elements of `list`.
InlinedVector(std::initializer_list<value_type> list,
const allocator_type& alloc = allocator_type())
: InlinedVector(list.begin(), list.end(), alloc) {}
// 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>* = nullptr>
InlinedVector(ForwardIterator first, ForwardIterator last,
const allocator_type& alloc = allocator_type())
: storage_(alloc) {
storage_.Initialize(IteratorValueAdapter<ForwardIterator>(first),
std::distance(first, last));
}
// Creates an inlined vector with elements constructed from the provided input
// iterator range [`first`, `last`).
template <typename InputIterator,
DisableIfAtLeastForwardIterator<InputIterator>* = nullptr>
InlinedVector(InputIterator first, InputIterator last,
const allocator_type& alloc = allocator_type())
: storage_(alloc) {
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_.GetAllocPtr()) {}
// Creates an inlined vector by copying the contents of `other` using `alloc`.
InlinedVector(const InlinedVector& other, const allocator_type& alloc)
: storage_(alloc) {
if (IsMemcpyOk::value && !other.storage_.GetIsAllocated()) {
storage_.MemcpyFrom(other.storage_);
} else {
storage_.Initialize(IteratorValueAdapter<const_pointer>(other.data()),
other.size());
}
}
// 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_.GetAllocPtr()) {
if (IsMemcpyOk::value) {
storage_.MemcpyFrom(other.storage_);
other.storage_.SetInlinedSize(0);
} else if (other.storage_.GetIsAllocated()) {
storage_.SetAllocatedData(other.storage_.GetAllocatedData(),
other.storage_.GetAllocatedCapacity());
storage_.SetAllocatedSize(other.storage_.GetSize());
other.storage_.SetInlinedSize(0);
} else {
IteratorValueAdapter<MoveIterator> other_values(
MoveIterator(other.storage_.GetInlinedData()));
inlined_vector_internal::ConstructElements(
storage_.GetAllocPtr(), 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 `alloc`.
//
// NOTE: if `other`'s allocator is not equal to `alloc`, 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& alloc) noexcept(
absl::allocator_is_nothrow<allocator_type>::value)
: storage_(alloc) {
if (IsMemcpyOk::value) {
storage_.MemcpyFrom(other.storage_);
other.storage_.SetInlinedSize(0);
} else if ((*storage_.GetAllocPtr() == *other.storage_.GetAllocPtr()) &&
other.storage_.GetIsAllocated()) {
storage_.SetAllocatedData(other.storage_.GetAllocatedData(),
other.storage_.GetAllocatedCapacity());
storage_.SetAllocatedSize(other.storage_.GetSize());
other.storage_.SetInlinedSize(0);
} else {
storage_.Initialize(
IteratorValueAdapter<MoveIterator>(MoveIterator(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 half of the max for `size_type`.
return (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 {
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 {
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_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_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) {
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 {
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_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_HARDENING_ASSERT(!empty());
return data()[0];
}
// `InlinedVector::back()`
//
// Returns a `reference` to the last element of the inlined vector.
reference back() {
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_HARDENING_ASSERT(!empty());
return data()[size() - 1];
}
// `InlinedVector::begin()`
//
// Returns an `iterator` to the beginning of the inlined vector.
iterator begin() noexcept { return data(); }
// Overload of `InlinedVector::begin()` that returns a `const_iterator` to
// the beginning of the inlined vector.
const_iterator begin() const noexcept { return data(); }
// `InlinedVector::end()`
//
// Returns an `iterator` to the end of the inlined vector.
iterator end() noexcept { return data() + size(); }
// Overload of `InlinedVector::end()` that returns a `const_iterator` to the
// end of the inlined vector.
const_iterator end() const noexcept { return data() + size(); }
// `InlinedVector::cbegin()`
//
// Returns a `const_iterator` to the beginning of the inlined vector.
const_iterator cbegin() const noexcept { return begin(); }
// `InlinedVector::cend()`
//
// Returns a `const_iterator` to the end of the inlined vector.
const_iterator cend() const noexcept { return end(); }
// `InlinedVector::rbegin()`
//
// Returns a `reverse_iterator` from the end of the inlined vector.
reverse_iterator rbegin() noexcept { 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 {
return const_reverse_iterator(end());
}
// `InlinedVector::rend()`
//
// Returns a `reverse_iterator` from the beginning of the inlined vector.
reverse_iterator rend() noexcept { 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 {
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 { return rbegin(); }
// `InlinedVector::crend()`
//
// Returns a `const_reverse_iterator` from the beginning of the inlined
// vector.
const_reverse_iterator crend() const noexcept { return rend(); }
// `InlinedVector::get_allocator()`
//
// Returns a copy of the inlined vector's allocator.
allocator_type get_allocator() const { return *storage_.GetAllocPtr(); }
// ---------------------------------------------------------------------------
// 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))) {
if (IsMemcpyOk::value || other.storage_.GetIsAllocated()) {
inlined_vector_internal::DestroyElements(storage_.GetAllocPtr(), data(),
size());
storage_.DeallocateIfAllocated();
storage_.MemcpyFrom(other.storage_);
other.storage_.SetInlinedSize(0);
} else {
storage_.Assign(IteratorValueAdapter<MoveIterator>(
MoveIterator(other.storage_.GetInlinedData())),
other.size());
}
}
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(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>* = nullptr>
void assign(ForwardIterator first, ForwardIterator last) {
storage_.Assign(IteratorValueAdapter<ForwardIterator>(first),
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>* = nullptr>
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(), 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(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) {
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, RValueReference v) {
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_HARDENING_ASSERT(pos >= begin());
ABSL_HARDENING_ASSERT(pos <= end());
if (ABSL_PREDICT_TRUE(n != 0)) {
value_type dealias = v;
return storage_.Insert(pos, CopyValueAdapter(dealias), n);
} 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) {
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>* = nullptr>
iterator insert(const_iterator pos, ForwardIterator first,
ForwardIterator last) {
ABSL_HARDENING_ASSERT(pos >= begin());
ABSL_HARDENING_ASSERT(pos <= end());
if (ABSL_PREDICT_TRUE(first != last)) {
return storage_.Insert(pos, IteratorValueAdapter<ForwardIterator>(first),
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>* = nullptr>
iterator insert(const_iterator pos, InputIterator first, InputIterator last) {
ABSL_HARDENING_ASSERT(pos >= begin());
ABSL_HARDENING_ASSERT(pos <= end());
size_type index = 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_HARDENING_ASSERT(pos >= begin());
ABSL_HARDENING_ASSERT(pos <= end());
value_type dealias(std::forward<Args>(args)...);
return storage_.Insert(pos,
IteratorValueAdapter<MoveIterator>(
MoveIterator(std::addressof(dealias))),
1);
}
// `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) {
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(RValueReference 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::destroy(*storage_.GetAllocPtr(), 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 dereferencable.
iterator erase(const_iterator pos) {
ABSL_HARDENING_ASSERT(pos >= begin());
ABSL_HARDENING_ASSERT(pos < end());
return storage_.Erase(pos, pos + 1);
}
// 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 dereferencable.
iterator erase(const_iterator from, const_iterator to) {
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::DestroyElements(storage_.GetAllocPtr(), 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()`
//
// Reduces memory usage by freeing unused memory. After being called, calls to
// `capacity()` will be equal to `max(N, size())`.
//
// If `size() <= N` and the inlined vector contains allocated memory, the
// elements will all be moved to the inlined space and the allocated memory
// will be deallocated.
//
// If `size() > N` and `size() < capacity()`, the elements will be moved to a
// smaller allocation.
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);
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 absl::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.
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 // ABSL_CONTAINER_INLINED_VECTOR_H_
