diff options
Diffstat (limited to 'third_party/abseil-cpp/absl/container/inlined_vector.h')
| -rw-r--r-- | third_party/abseil-cpp/absl/container/inlined_vector.h | 848 |
1 files changed, 848 insertions, 0 deletions
diff --git a/third_party/abseil-cpp/absl/container/inlined_vector.h b/third_party/abseil-cpp/absl/container/inlined_vector.h new file mode 100644 index 0000000000..2388d471dc --- /dev/null +++ b/third_party/abseil-cpp/absl/container/inlined_vector.h @@ -0,0 +1,848 @@ +// 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/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) { + 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 { + 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() { + assert(!empty()); + + return at(0); + } + + // Overload of `InlinedVector::front()` that returns a `const_reference` to + // the first element of the inlined vector. + const_reference front() const { + assert(!empty()); + + return at(0); + } + + // `InlinedVector::back()` + // + // Returns a `reference` to the last element of the inlined vector. + reference back() { + assert(!empty()); + + return at(size() - 1); + } + + // Overload of `InlinedVector::back()` that returns a `const_reference` to the + // last element of the inlined vector. + const_reference back() const { + assert(!empty()); + + return at(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)) { + at(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) { 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) { + 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) { + assert(pos >= begin()); + 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) { + assert(pos >= begin()); + 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) { + assert(pos >= begin()); + 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) { + assert(pos >= begin()); + 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 { + 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) { + assert(pos >= begin()); + 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) { + assert(from >= begin()); + assert(from <= to); + 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_ |