[libcxx-commits] [libcxx] [libc++] Implement P0429R9 `std::flat_map` (PR #98643)
Louis Dionne via libcxx-commits
libcxx-commits at lists.llvm.org
Fri Aug 30 11:12:10 PDT 2024
================
@@ -0,0 +1,1367 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___FLAT_MAP_FLAT_MAP_H
+#define _LIBCPP___FLAT_MAP_FLAT_MAP_H
+
+#include <__algorithm/lexicographical_compare_three_way.h>
+#include <__algorithm/ranges_equal.h>
+#include <__algorithm/ranges_lower_bound.h>
+#include <__algorithm/ranges_partition_point.h>
+#include <__algorithm/ranges_stable_sort.h>
+#include <__algorithm/ranges_unique.h>
+#include <__algorithm/ranges_upper_bound.h>
+#include <__compare/synth_three_way.h>
+#include <__concepts/convertible_to.h>
+#include <__config>
+#include <__flat_map/sorted_unique.h>
+#include <__functional/invoke.h>
+#include <__functional/is_transparent.h>
+#include <__functional/operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/distance.h>
+#include <__iterator/iterator_traits.h>
+#include <__iterator/ranges_iterator_traits.h>
+#include <__iterator/reverse_iterator.h>
+#include <__memory/allocator_traits.h>
+#include <__memory/uses_allocator.h>
+#include <__memory/uses_allocator_construction.h>
+#include <__ranges/concepts.h>
+#include <__ranges/container_compatible_range.h>
+#include <__ranges/ref_view.h>
+#include <__ranges/subrange.h>
+#include <__ranges/zip_view.h>
+#include <__type_traits/conjunction.h>
+#include <__type_traits/invoke.h>
+#include <__type_traits/is_allocator.h>
+#include <__type_traits/is_nothrow_constructible.h>
+#include <__type_traits/maybe_const.h>
+#include <__utility/pair.h>
+#include <initializer_list>
+#include <stdexcept>
+#include <string>
+#include <vector>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+# pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER >= 23
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Key,
+ class _Tp,
+ class _Compare = less<_Key>,
+ class _KeyContainer = vector<_Key>,
+ class _MappedContainer = vector<_Tp>>
+class flat_map {
+ template <bool _Const>
+ struct __iterator;
+
+ template <class, class, class, class, class>
+ friend class flat_map;
+
+public:
+ // types
+ using key_type = _Key;
+ using mapped_type = _Tp;
+ using value_type = pair<key_type, mapped_type>;
+ using key_compare = _Compare;
+ // TODO : the following is the spec, but not implementable for vector<bool>
+ // using reference = pair<const key_type&, mapped_type&>;
+ // using const_reference = pair<const key_type&, const mapped_type&>;
+ using reference = pair<ranges::range_reference_t<const _KeyContainer>, ranges::range_reference_t<_MappedContainer>>;
+ using const_reference =
+ pair<ranges::range_reference_t<const _KeyContainer>, ranges::range_reference_t<const _MappedContainer>>;
+ using size_type = size_t;
+ using difference_type = ptrdiff_t;
+ using iterator = __iterator<false>; // see [container.requirements]
+ using const_iterator = __iterator<true>; // see [container.requirements]
+ using reverse_iterator = std::reverse_iterator<iterator>;
+ using const_reverse_iterator = std::reverse_iterator<const_iterator>;
+ using key_container_type = _KeyContainer;
+ using mapped_container_type = _MappedContainer;
+
+ class value_compare {
+ private:
+ key_compare __comp_;
+ value_compare(key_compare __c) : __comp_(__c) {}
+ friend flat_map;
+
+ public:
+ _LIBCPP_HIDE_FROM_ABI bool operator()(const_reference __x, const_reference __y) const {
+ return __comp_(__x.first, __y.first);
+ }
+ };
+
+ struct containers {
+ key_container_type keys;
+ mapped_container_type values;
+ };
+
+private:
+ template <class _Allocator>
+ _LIBCPP_HIDE_FROM_ABI static constexpr bool __allocator_ctor_constraint =
+ _And<uses_allocator<key_container_type, _Allocator>, uses_allocator<mapped_container_type, _Allocator>>::value;
+
+ _LIBCPP_HIDE_FROM_ABI static constexpr bool __is_compare_transparent = __is_transparent_v<_Compare, _Compare>;
+
+ template <bool _Const>
+ struct __iterator {
+ private:
+ using __key_iterator = ranges::iterator_t<const key_container_type>;
+ using __mapped_iterator = ranges::iterator_t<__maybe_const<_Const, mapped_container_type>>;
+ using __reference = pair<iter_reference_t<__key_iterator>, iter_reference_t<__mapped_iterator>>;
+
+ struct __arrow_proxy {
+ __reference __ref_;
+ _LIBCPP_HIDE_FROM_ABI __reference* operator->() { return std::addressof(__ref_); }
+ };
+
+ __key_iterator __key_iter_;
+ __mapped_iterator __mapped_iter_;
+
+ friend flat_map;
+
+ public:
+ using iterator_concept = random_access_iterator_tag;
+ using iterator_category = input_iterator_tag;
+ using value_type = flat_map::value_type;
+ using difference_type = flat_map::difference_type;
+
+ _LIBCPP_HIDE_FROM_ABI __iterator() = default;
+
+ _LIBCPP_HIDE_FROM_ABI __iterator(__iterator<!_Const> __i)
+ requires _Const && convertible_to<ranges::iterator_t<key_container_type>, __key_iterator> &&
+ convertible_to<ranges::iterator_t<mapped_container_type>, __mapped_iterator>
+ : __key_iter_(std::move(__i.__key_iter_)), __mapped_iter_(std::move(__i.__mapped_iter_)) {}
+
+ _LIBCPP_HIDE_FROM_ABI __iterator(__key_iterator __key_iter, __mapped_iterator __mapped_iter)
+ : __key_iter_(std::move(__key_iter)), __mapped_iter_(std::move(__mapped_iter)) {}
+
+ _LIBCPP_HIDE_FROM_ABI __reference operator*() const { return __reference(*__key_iter_, *__mapped_iter_); }
+ _LIBCPP_HIDE_FROM_ABI __arrow_proxy operator->() const { return __arrow_proxy(**this); }
+
+ _LIBCPP_HIDE_FROM_ABI __iterator& operator++() {
+ ++__key_iter_;
+ ++__mapped_iter_;
+ return *this;
+ }
+
+ _LIBCPP_HIDE_FROM_ABI __iterator operator++(int) {
+ __iterator __tmp(*this);
+ ++*this;
+ return __tmp;
+ }
+
+ _LIBCPP_HIDE_FROM_ABI __iterator& operator--() {
+ --__key_iter_;
+ --__mapped_iter_;
+ return *this;
+ }
+
+ _LIBCPP_HIDE_FROM_ABI __iterator operator--(int) {
+ __iterator __tmp(*this);
+ --*this;
+ return __tmp;
+ }
+
+ _LIBCPP_HIDE_FROM_ABI __iterator& operator+=(difference_type __x) {
+ __key_iter_ += __x;
+ __mapped_iter_ += __x;
+ return *this;
+ }
+
+ _LIBCPP_HIDE_FROM_ABI __iterator& operator-=(difference_type __x) {
+ __key_iter_ -= __x;
+ __mapped_iter_ -= __x;
+ return *this;
+ }
+
+ _LIBCPP_HIDE_FROM_ABI __reference operator[](difference_type __n) const { return *(*this + __n); }
+
+ _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const __iterator& __x, const __iterator& __y) {
+ return __x.__key_iter_ == __y.__key_iter_;
+ }
+
+ _LIBCPP_HIDE_FROM_ABI friend bool operator<(const __iterator& __x, const __iterator& __y) {
+ return __x.__key_iter_ < __y.__key_iter_;
+ }
+
+ _LIBCPP_HIDE_FROM_ABI friend bool operator>(const __iterator& __x, const __iterator& __y) { return __y < __x; }
+
+ _LIBCPP_HIDE_FROM_ABI friend bool operator<=(const __iterator& __x, const __iterator& __y) { return !(__y < __x); }
+
+ _LIBCPP_HIDE_FROM_ABI friend bool operator>=(const __iterator& __x, const __iterator& __y) { return !(__x < __y); }
+
+ _LIBCPP_HIDE_FROM_ABI friend auto operator<=>(const __iterator& __x, const __iterator& __y)
+ requires three_way_comparable<__key_iterator>
+ {
+ return __x.__key_iter_ <=> __y.__key_iter_;
+ }
+
+ _LIBCPP_HIDE_FROM_ABI friend __iterator operator+(const __iterator& __i, difference_type __n) {
+ auto __tmp = __i;
+ __tmp += __n;
+ return __tmp;
+ }
+
+ _LIBCPP_HIDE_FROM_ABI friend __iterator operator+(difference_type __n, const __iterator& __i) { return __i + __n; }
+
+ _LIBCPP_HIDE_FROM_ABI friend __iterator operator-(const __iterator& __i, difference_type __n) {
+ auto __tmp = __i;
+ __tmp -= __n;
+ return __tmp;
+ }
+
+ _LIBCPP_HIDE_FROM_ABI friend difference_type operator-(const __iterator& __x, const __iterator& __y) {
+ return difference_type(__x.__key_iter_ - __y.__key_iter_);
+ }
+ };
+
+public:
+ // [flat.map.cons], construct/copy/destroy
+ _LIBCPP_HIDE_FROM_ABI flat_map() noexcept(
+ is_nothrow_default_constructible_v<_KeyContainer> && is_nothrow_default_constructible_v<_MappedContainer> &&
+ is_nothrow_default_constructible_v<_Compare>)
+ : __containers_(), __compare_() {}
+
+ template <class _Allocator>
+ requires __allocator_ctor_constraint<_Allocator>
+ _LIBCPP_HIDE_FROM_ABI flat_map(const flat_map& __other, const _Allocator& __alloc)
+ : flat_map(__ctor_uses_allocator_tag{},
+ __alloc,
+ __other.__containers_.keys,
+ __other.__containers_.values,
+ __other.__compare_) {}
+
+ template <class _Allocator>
+ requires __allocator_ctor_constraint<_Allocator>
+ _LIBCPP_HIDE_FROM_ABI flat_map(flat_map&& __other, const _Allocator& __alloc)
+ : flat_map(__ctor_uses_allocator_tag{},
+ __alloc,
+ std::move(__other.__containers_.keys),
+ std::move(__other.__containers_.values),
+ std::move(__other.__compare_)) {}
+
+ _LIBCPP_HIDE_FROM_ABI flat_map(
+ key_container_type __key_cont, mapped_container_type __mapped_cont, const key_compare& __comp = key_compare())
+ : __containers_{.keys = std::move(__key_cont), .values = std::move(__mapped_cont)}, __compare_(__comp) {
+ __sort_and_unique();
+ }
+
+ template <class _Allocator>
+ requires __allocator_ctor_constraint<_Allocator>
+ _LIBCPP_HIDE_FROM_ABI
+ flat_map(const key_container_type& __key_cont, const mapped_container_type& __mapped_cont, const _Allocator& __alloc)
+ : flat_map(__ctor_uses_allocator_tag{}, __alloc, __key_cont, __mapped_cont) {
+ __sort_and_unique();
+ }
+
+ template <class _Allocator>
+ requires __allocator_ctor_constraint<_Allocator>
+ _LIBCPP_HIDE_FROM_ABI
+ flat_map(const key_container_type& __key_cont,
+ const mapped_container_type& __mapped_cont,
+ const key_compare& __comp,
+ const _Allocator& __alloc)
+ : flat_map(__ctor_uses_allocator_tag{}, __alloc, __key_cont, __mapped_cont, __comp) {
+ __sort_and_unique();
+ }
+
+ _LIBCPP_HIDE_FROM_ABI
+ flat_map(sorted_unique_t,
+ key_container_type __key_cont,
+ mapped_container_type __mapped_cont,
+ const key_compare& __comp = key_compare())
+ : __containers_{.keys = std::move(__key_cont), .values = std::move(__mapped_cont)}, __compare_(__comp) {}
+
+ template <class _Allocator>
+ requires __allocator_ctor_constraint<_Allocator>
+ _LIBCPP_HIDE_FROM_ABI
+ flat_map(sorted_unique_t,
+ const key_container_type& __key_cont,
+ const mapped_container_type& __mapped_cont,
+ const _Allocator& __alloc)
+ : flat_map(__ctor_uses_allocator_tag{}, __alloc, __key_cont, __mapped_cont) {}
+
+ template <class _Allocator>
+ requires __allocator_ctor_constraint<_Allocator>
+ _LIBCPP_HIDE_FROM_ABI
+ flat_map(sorted_unique_t,
+ const key_container_type& __key_cont,
+ const mapped_container_type& __mapped_cont,
+ const key_compare& __comp,
+ const _Allocator& __alloc)
+ : flat_map(__ctor_uses_allocator_tag{}, __alloc, __key_cont, __mapped_cont, __comp) {}
+
+ _LIBCPP_HIDE_FROM_ABI explicit flat_map(const key_compare& __comp) : __containers_(), __compare_(__comp) {}
+
+ template <class _Allocator>
+ requires __allocator_ctor_constraint<_Allocator>
+ _LIBCPP_HIDE_FROM_ABI flat_map(const key_compare& __comp, const _Allocator& __alloc)
+ : flat_map(__ctor_uses_allocator_empty_tag{}, __alloc, __comp) {}
+
+ template <class _Allocator>
+ requires __allocator_ctor_constraint<_Allocator>
+ _LIBCPP_HIDE_FROM_ABI explicit flat_map(const _Allocator& __alloc)
+ : flat_map(__ctor_uses_allocator_empty_tag{}, __alloc) {}
+
+ template <input_iterator _InputIterator>
+ _LIBCPP_HIDE_FROM_ABI
+ flat_map(_InputIterator __first, _InputIterator __last, const key_compare& __comp = key_compare())
+ : __containers_(), __compare_(__comp) {
+ insert(__first, __last);
+ }
+
+ template <input_iterator _InputIterator, class _Allocator>
+ requires __allocator_ctor_constraint<_Allocator>
+ _LIBCPP_HIDE_FROM_ABI
+ flat_map(_InputIterator __first, _InputIterator __last, const key_compare& __comp, const _Allocator& __alloc)
+ : flat_map(__ctor_uses_allocator_empty_tag{}, __alloc, __comp) {
+ insert(__first, __last);
+ }
+
+ template <input_iterator _InputIterator, class _Allocator>
+ requires __allocator_ctor_constraint<_Allocator>
+ _LIBCPP_HIDE_FROM_ABI flat_map(_InputIterator __first, _InputIterator __last, const _Allocator& __alloc)
+ : flat_map(__ctor_uses_allocator_empty_tag{}, __alloc) {
+ insert(__first, __last);
+ }
+
+ template <_ContainerCompatibleRange<value_type> _Range>
+ _LIBCPP_HIDE_FROM_ABI flat_map(from_range_t __fr, _Range&& __rg)
+ : flat_map(__fr, std::forward<_Range>(__rg), key_compare()) {}
+
+ template <_ContainerCompatibleRange<value_type> _Range, class _Allocator>
+ requires __allocator_ctor_constraint<_Allocator>
+ _LIBCPP_HIDE_FROM_ABI flat_map(from_range_t, _Range&& __rg, const _Allocator& __alloc)
+ : flat_map(__ctor_uses_allocator_empty_tag{}, __alloc) {
+ insert_range(std::forward<_Range>(__rg));
+ }
+
+ template <_ContainerCompatibleRange<value_type> _Range>
+ _LIBCPP_HIDE_FROM_ABI flat_map(from_range_t, _Range&& __rg, const key_compare& __comp) : flat_map(__comp) {
+ insert_range(std::forward<_Range>(__rg));
+ }
+
+ template <_ContainerCompatibleRange<value_type> _Range, class _Allocator>
+ _LIBCPP_HIDE_FROM_ABI flat_map(from_range_t, _Range&& __rg, const key_compare& __comp, const _Allocator& __alloc)
+ : flat_map(__ctor_uses_allocator_empty_tag{}, __alloc, __comp) {
+ insert_range(std::forward<_Range>(__rg));
+ }
+
+ template <input_iterator _InputIterator>
+ _LIBCPP_HIDE_FROM_ABI flat_map(
+ sorted_unique_t __s, _InputIterator __first, _InputIterator __last, const key_compare& __comp = key_compare())
+ : __containers_(), __compare_(__comp) {
+ insert(__s, __first, __last);
+ }
+ template <input_iterator _InputIterator, class _Allocator>
+ requires __allocator_ctor_constraint<_Allocator>
+ _LIBCPP_HIDE_FROM_ABI
+ flat_map(sorted_unique_t __s,
+ _InputIterator __first,
+ _InputIterator __last,
+ const key_compare& __comp,
+ const _Allocator& __alloc)
+ : flat_map(__ctor_uses_allocator_empty_tag{}, __alloc, __comp) {
+ insert(__s, __first, __last);
+ }
+
+ template <input_iterator _InputIterator, class _Allocator>
+ requires __allocator_ctor_constraint<_Allocator>
+ _LIBCPP_HIDE_FROM_ABI
+ flat_map(sorted_unique_t __s, _InputIterator __first, _InputIterator __last, const _Allocator& __alloc)
+ : flat_map(__ctor_uses_allocator_empty_tag{}, __alloc) {
+ insert(__s, __first, __last);
+ }
+
+ _LIBCPP_HIDE_FROM_ABI flat_map(initializer_list<value_type> __il, const key_compare& __comp = key_compare())
+ : flat_map(__il.begin(), __il.end(), __comp) {}
+
+ template <class _Allocator>
+ requires __allocator_ctor_constraint<_Allocator>
+ _LIBCPP_HIDE_FROM_ABI
+ flat_map(initializer_list<value_type> __il, const key_compare& __comp, const _Allocator& __alloc)
+ : flat_map(__il.begin(), __il.end(), __comp, __alloc) {}
+
+ template <class _Allocator>
+ requires __allocator_ctor_constraint<_Allocator>
+ _LIBCPP_HIDE_FROM_ABI flat_map(initializer_list<value_type> __il, const _Allocator& __alloc)
+ : flat_map(__il.begin(), __il.end(), __alloc) {}
+
+ _LIBCPP_HIDE_FROM_ABI
+ flat_map(sorted_unique_t __s, initializer_list<value_type> __il, const key_compare& __comp = key_compare())
+ : flat_map(__s, __il.begin(), __il.end(), __comp) {}
+
+ template <class _Allocator>
+ requires __allocator_ctor_constraint<_Allocator>
+ _LIBCPP_HIDE_FROM_ABI
+ flat_map(sorted_unique_t __s, initializer_list<value_type> __il, const key_compare& __comp, const _Allocator& __alloc)
+ : flat_map(__s, __il.begin(), __il.end(), __comp, __alloc) {}
+
+ template <class _Allocator>
+ requires __allocator_ctor_constraint<_Allocator>
+ _LIBCPP_HIDE_FROM_ABI flat_map(sorted_unique_t __s, initializer_list<value_type> __il, const _Allocator& __alloc)
+ : flat_map(__s, __il.begin(), __il.end(), __alloc) {}
+
+ _LIBCPP_HIDE_FROM_ABI flat_map& operator=(initializer_list<value_type> __il) {
+ clear();
+ insert(__il);
+ return *this;
+ }
+
+ // iterators
+ _LIBCPP_HIDE_FROM_ABI iterator begin() noexcept {
+ return iterator(__containers_.keys.begin(), __containers_.values.begin());
+ }
+
+ _LIBCPP_HIDE_FROM_ABI const_iterator begin() const noexcept {
+ return const_iterator(__containers_.keys.begin(), __containers_.values.begin());
+ }
+
+ _LIBCPP_HIDE_FROM_ABI iterator end() noexcept {
+ return iterator(__containers_.keys.end(), __containers_.values.end());
+ }
+
+ _LIBCPP_HIDE_FROM_ABI const_iterator end() const noexcept {
+ return const_iterator(__containers_.keys.end(), __containers_.values.end());
+ }
+
+ _LIBCPP_HIDE_FROM_ABI reverse_iterator rbegin() noexcept { return reverse_iterator(end()); }
+ _LIBCPP_HIDE_FROM_ABI const_reverse_iterator rbegin() const noexcept { const_reverse_iterator(end()); }
+ _LIBCPP_HIDE_FROM_ABI reverse_iterator rend() noexcept { return reverse_iterator(begin()); }
+ _LIBCPP_HIDE_FROM_ABI const_reverse_iterator rend() const noexcept { return const_reverse_iterator(begin()); }
+
+ _LIBCPP_HIDE_FROM_ABI const_iterator cbegin() const noexcept { return begin(); }
+ _LIBCPP_HIDE_FROM_ABI const_iterator cend() const noexcept { return end(); }
+ _LIBCPP_HIDE_FROM_ABI const_reverse_iterator crbegin() const noexcept { return const_reverse_iterator(end()); }
+ _LIBCPP_HIDE_FROM_ABI const_reverse_iterator crend() const noexcept { return const_reverse_iterator(begin()); }
+
+ // [flat.map.capacity], capacity
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI bool empty() const noexcept { return __containers_.keys.empty(); }
+
+ _LIBCPP_HIDE_FROM_ABI size_type size() const noexcept { return __containers_.keys.size(); }
+
+ _LIBCPP_HIDE_FROM_ABI size_type max_size() const noexcept {
+ return std::min<size_type>(__containers_.keys.max_size(), __containers_.values.max_size());
+ }
+
+ // [flat.map.access], element access
+ _LIBCPP_HIDE_FROM_ABI mapped_type& operator[](const key_type& __x) { return try_emplace(__x).first->second; }
+
+ _LIBCPP_HIDE_FROM_ABI mapped_type& operator[](key_type&& __x) { return try_emplace(std::move(__x)).first->second; }
+
+ template <class _Kp>
+ requires __is_compare_transparent
+ _LIBCPP_HIDE_FROM_ABI mapped_type& operator[](_Kp&& __x) {
+ return try_emplace(std::forward<_Kp>(__x)).first->second;
+ }
+
+ _LIBCPP_HIDE_FROM_ABI mapped_type& at(const key_type& __x) {
+ auto __it = find(__x);
+ if (__it == end()) {
+ __throw_out_of_range("flat_map::at(const key_type&): Key does not exist");
+ }
+ return (*__it).second;
+ }
+
+ _LIBCPP_HIDE_FROM_ABI const mapped_type& at(const key_type& __x) const {
+ auto __it = find(__x);
+ if (__it == end()) {
+ __throw_out_of_range("flat_map::at(const key_type&) const: Key does not exist");
+ }
+ return (*__it).second;
+ }
+
+ template <class _Kp>
+ requires __is_compare_transparent
+ _LIBCPP_HIDE_FROM_ABI mapped_type& at(const _Kp& __x) {
+ static_assert(requires { find(__x); }, "flat_map::at(const K& x): find(x) needs to be well-formed");
+ auto __it = find(__x);
+ if (__it == end()) {
+ __throw_out_of_range("flat_map::at(const K&): Key does not exist");
+ }
+ return (*__it).second;
+ }
+
+ template <class _Kp>
+ requires __is_compare_transparent
+ _LIBCPP_HIDE_FROM_ABI const mapped_type& at(const _Kp& __x) const {
+ static_assert(requires { find(__x); }, "flat_map::at(const K& x) const: find(x) needs to be well-formed");
+ auto __it = find(__x);
+ if (__it == end()) {
+ __throw_out_of_range("flat_map::at(const K&) const: Key does not exist");
+ }
+ return (*__it).second;
+ }
+
+ // [flat.map.modifiers], modifiers
+ template <class... _Args>
+ requires is_constructible_v<pair<key_type, mapped_type>, _Args...>
+ _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> emplace(_Args&&... __args) {
+ std::pair<key_type, mapped_type> __pair(std::forward<_Args>(__args)...);
+ return __binary_search_emplace_impl(std::move(__pair));
+ }
+
+ template <class... _Args>
+ requires is_constructible_v<pair<key_type, mapped_type>, _Args...>
+ _LIBCPP_HIDE_FROM_ABI iterator emplace_hint(const_iterator __hint, _Args&&... __args) {
+ std::pair<key_type, mapped_type> __pair(std::forward<_Args>(__args)...);
+ if (__is_hint_correct(__hint, __pair.first)) {
+ if (__compare_(__pair.first, __hint->first)) {
+ return __emplace_impl(__hint, std::move(__pair));
+ } else {
+ // key equals
+ auto __dist = __hint - cbegin();
+ return iterator(__containers_.keys.begin() + __dist, __containers_.values.begin() + __dist);
+ }
+ } else {
+ return __binary_search_emplace_impl(std::move(__pair)).first;
+ }
+ }
+
+ _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> insert(const value_type& __x) { return emplace(__x); }
+
+ _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> insert(value_type&& __x) { return emplace(std::move(__x)); }
+
+ _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __hint, const value_type& __x) {
+ return emplace_hint(__hint, __x);
+ }
+
+ _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __hint, value_type&& __x) {
+ return emplace_hint(__hint, std::move(__x));
+ }
+
+ template <class _Pp>
+ requires is_constructible_v<pair<key_type, mapped_type>, _Pp>
+ _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> insert(_Pp&& __x) {
+ return emplace(std::forward<_Pp>(__x));
+ }
+
+ template <class _Pp>
+ requires is_constructible_v<pair<key_type, mapped_type>, _Pp>
+ _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __hint, _Pp&& __x) {
+ return emplace_hint(__hint, std::forward<_Pp>(__x));
+ }
+
+ template <input_iterator _InputIterator>
+ _LIBCPP_HIDE_FROM_ABI void insert(_InputIterator __first, _InputIterator __last) {
+ if constexpr (sized_sentinel_for<_InputIterator, _InputIterator>) {
+ __reserve_impl(__last - __first);
+ }
+
+ for (; __first != __last; ++__first) {
+ __binary_search_emplace_impl(value_type(*__first));
+ }
+ }
+
+ template <input_iterator _InputIterator>
+ void insert(sorted_unique_t, _InputIterator __first, _InputIterator __last) {
+ if constexpr (sized_sentinel_for<_InputIterator, _InputIterator>) {
+ __reserve_impl(__last - __first);
+ }
+
+ auto __it = begin();
+ while (__first != __last) {
+ value_type __pair(*__first);
+ auto __end = end();
+ __it = ranges::lower_bound(__it, __end, __pair.first, __compare_, [](const auto& __p) -> decltype(auto) {
+ return std::get<0>(__p);
+ });
+ if (__it == __end || __compare_(__pair.first, __it->first)) {
+ __it = __emplace_impl(__it, std::move(__pair));
+ }
+ ++__it;
+ ++__first;
+ }
+ }
+
+ template <_ContainerCompatibleRange<value_type> _Range>
+ _LIBCPP_HIDE_FROM_ABI void insert_range(_Range&& __range) {
+ if constexpr (ranges::sized_range<_Range>) {
+ __reserve_impl(ranges::size(__range));
+ }
+
+ auto __last = ranges::end(__range);
+ for (auto __it = ranges::begin(__range); __it != __last; ++__it) {
+ __binary_search_emplace_impl(value_type(*__it));
+ }
+ }
+
+ _LIBCPP_HIDE_FROM_ABI void insert(initializer_list<value_type> __il) { insert(__il.begin(), __il.end()); }
+
+ _LIBCPP_HIDE_FROM_ABI void insert(sorted_unique_t __s, initializer_list<value_type> __il) {
+ insert(__s, __il.begin(), __il.end());
+ }
+
+ _LIBCPP_HIDE_FROM_ABI containers extract() && {
+# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
+ try {
+# endif // _LIBCPP_HAS_NO_EXCEPTIONS
+ return std::move(__containers_);
+# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
+ } catch (...) {
+ clear();
+ throw;
+ }
+# endif // _LIBCPP_HAS_NO_EXCEPTIONS
+ }
+
+ _LIBCPP_HIDE_FROM_ABI void replace(key_container_type&& __key_cont, mapped_container_type&& __mapped_cont) {
+# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
+ try {
+# endif // _LIBCPP_HAS_NO_EXCEPTIONS
+ __containers_.keys = std::move(__key_cont);
+ __containers_.values = std::move(__mapped_cont);
+# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
+ } catch (...) {
+ clear();
+ throw;
+ }
+# endif // _LIBCPP_HAS_NO_EXCEPTIONS
+ }
+
+ template <class... _Args>
+ requires is_constructible_v<mapped_type, _Args...>
+ _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> try_emplace(const key_type& __key, _Args&&... __args) {
+ return __binary_search_try_emplace_impl(__key, std::forward<_Args>(__args)...);
+ }
+
+ template <class... _Args>
+ requires is_constructible_v<mapped_type, _Args...>
+ _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> try_emplace(key_type&& __key, _Args&&... __args) {
+ return __binary_search_try_emplace_impl(std::move(__key), std::forward<_Args>(__args)...);
+ }
+
+ template <class _Kp, class... _Args>
+ requires __is_compare_transparent && is_constructible_v<key_type, _Kp> &&
+ is_constructible_v<mapped_type, _Args...> && is_convertible_v<_Kp&&, const_iterator> &&
+ is_convertible_v<_Kp&&, iterator>
+ _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> try_emplace(_Kp&& __key, _Args&&... __args) {
+ return __binary_search_try_emplace_impl(std::forward<_Kp>(__key), std::forward<_Args>(__args)...);
+ }
+
+ template <class... _Args>
+ requires is_constructible_v<mapped_type, _Args...>
+ _LIBCPP_HIDE_FROM_ABI iterator try_emplace(const_iterator __hint, const key_type& __key, _Args&&... __args) {
+ return try_emplace_hint_impl(__hint, __key, std::forward<_Args>(__args)...);
+ }
+
+ template <class... _Args>
+ requires is_constructible_v<mapped_type, _Args...>
+ _LIBCPP_HIDE_FROM_ABI iterator try_emplace(const_iterator __hint, key_type&& __key, _Args&&... __args) {
+ return try_emplace_hint_impl(__hint, std::move(__key), std::forward<_Args>(__args)...);
+ }
+
+ template <class _Kp, class... _Args>
+ requires __is_compare_transparent && is_constructible_v<key_type, _Kp> && is_constructible_v<mapped_type, _Args...>
+ _LIBCPP_HIDE_FROM_ABI iterator try_emplace(const_iterator __hint, _Kp&& __key, _Args&&... __args) {
+ return try_emplace_hint_impl(__hint, std::forward<_Kp>(__key), std::forward<_Args>(__args)...);
+ }
+
+ template <class _Mapped>
+ requires is_assignable_v<mapped_type&, _Mapped> && is_constructible_v<mapped_type, _Mapped>
+ _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> insert_or_assign(const key_type& __key, _Mapped&& __obj) {
+ return __insert_or_assign_impl(__key, std::forward<_Mapped>(__obj));
+ }
+
+ template <class _Mapped>
+ requires is_assignable_v<mapped_type&, _Mapped> && is_constructible_v<mapped_type, _Mapped>
+ _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> insert_or_assign(key_type&& __key, _Mapped&& __obj) {
+ return __insert_or_assign_impl(std::move(__key), std::forward<_Mapped>(__obj));
+ }
+
+ template <class _Kp, class _Mapped>
+ requires __is_compare_transparent && is_constructible_v<key_type, _Kp> && is_assignable_v<mapped_type&, _Mapped> &&
+ is_constructible_v<mapped_type, _Mapped>
+ _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> insert_or_assign(_Kp&& __key, _Mapped&& __obj) {
+ return __insert_or_assign_impl(std::forward<_Kp>(__key), std::forward<_Mapped>(__obj));
+ }
+
+ template <class _Mapped>
+ requires is_assignable_v<mapped_type&, _Mapped> && is_constructible_v<mapped_type, _Mapped>
+ _LIBCPP_HIDE_FROM_ABI iterator insert_or_assign(const_iterator __hint, const key_type& __key, _Mapped&& __obj) {
+ return __insert_or_assign_impl(__key, std::forward<_Mapped>(__obj), __hint).first;
+ }
+
+ template <class _Mapped>
+ requires is_assignable_v<mapped_type&, _Mapped> && is_constructible_v<mapped_type, _Mapped>
+ _LIBCPP_HIDE_FROM_ABI iterator insert_or_assign(const_iterator __hint, key_type&& __key, _Mapped&& __obj) {
+ return __insert_or_assign_impl(std::move(__key), std::forward<_Mapped>(__obj), __hint).first;
+ }
+
+ template <class _Kp, class _Mapped>
+ requires __is_compare_transparent && is_constructible_v<key_type, _Kp> && is_assignable_v<mapped_type&, _Mapped> &&
+ is_constructible_v<mapped_type, _Mapped>
+ _LIBCPP_HIDE_FROM_ABI iterator insert_or_assign(const_iterator __hint, _Kp&& __key, _Mapped&& __obj) {
+ return __insert_or_assign_impl(std::forward<_Kp>(__key), std::forward<_Mapped>(__obj), __hint).first;
+ }
+
+ _LIBCPP_HIDE_FROM_ABI iterator erase(iterator __position) {
+ return __erase_impl(__position.__key_iter_, __position.__mapped_iter_);
+ }
+
+ _LIBCPP_HIDE_FROM_ABI iterator erase(const_iterator __position) {
+ return __erase_impl(__position.__key_iter_, __position.__mapped_iter_);
+ }
+
+ _LIBCPP_HIDE_FROM_ABI size_type erase(const key_type& __x) {
+ auto __iter = find(__x);
+ if (__iter != end()) {
+ erase(__iter);
+ return 1;
+ }
+ return 0;
+ }
+
+ template <class _Kp>
+ requires(__is_compare_transparent && !is_convertible_v<_Kp &&, iterator> &&
+ !is_convertible_v<_Kp &&, const_iterator>)
+ _LIBCPP_HIDE_FROM_ABI size_type erase(_Kp&& __x) {
+ auto [__first, __last] = equal_range(__x);
+ auto __res = __last - __first;
+ erase(__first, __last);
+ return __res;
+ }
+
+ _LIBCPP_HIDE_FROM_ABI iterator erase(const_iterator __first, const_iterator __last) {
+# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
+ try {
+# endif // _LIBCPP_HAS_NO_EXCEPTIONS
+ auto __key_it = __containers_.keys.erase(__first.__key_iter_, __last.__key_iter_);
+ auto __mapped_it = __containers_.values.erase(__first.__mapped_iter_, __last.__mapped_iter_);
+ return iterator(std::move(__key_it), std::move(__mapped_it));
+# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
+ } catch (const exception& __ex) {
+ clear();
+ throw __flat_map_restore_error(
+ std::string("flat_map::erase: "
+ "Unable to restore flat_map to previous state. Clear out the containers to make the two "
+ "containers consistent. Reason: ") +
+ __ex.what());
+ } catch (...) {
+ clear();
+ throw __flat_map_restore_error(
+ "flat_map::erase: "
+ "Unable to restore flat_map to previous state. Clear out the containers to make the two "
+ "containers consistent.");
+ }
+# endif // _LIBCPP_HAS_NO_EXCEPTIONS
+ }
+
+ _LIBCPP_HIDE_FROM_ABI void swap(flat_map& __y) noexcept {
+# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
+ try {
+# endif // _LIBCPP_HAS_NO_EXCEPTIONS
+ using std::swap;
+ swap(__compare_, __y.__compare_);
+ swap(__containers_.keys, __y.__containers_.keys);
+ swap(__containers_.values, __y.__containers_.values);
+# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
+ } catch (...) {
+ clear();
+ __y.clear();
+ }
+# endif // _LIBCPP_HAS_NO_EXCEPTIONS
+ }
+
+ _LIBCPP_HIDE_FROM_ABI void clear() noexcept {
+ __containers_.keys.clear();
+ __containers_.values.clear();
+ }
+
+ // observers
+ _LIBCPP_HIDE_FROM_ABI key_compare key_comp() const { return __compare_; }
+ _LIBCPP_HIDE_FROM_ABI value_compare value_comp() const { return value_compare(__compare_); }
+ _LIBCPP_HIDE_FROM_ABI const key_container_type& keys() const noexcept { return __containers_.keys; }
+ _LIBCPP_HIDE_FROM_ABI const mapped_container_type& values() const noexcept { return __containers_.values; }
+
+ // map operations
+ _LIBCPP_HIDE_FROM_ABI iterator find(const key_type& __x) { return __find_impl(*this, __x); }
+
+ _LIBCPP_HIDE_FROM_ABI const_iterator find(const key_type& __x) const { return __find_impl(*this, __x); }
+
+ template <class _Kp>
+ requires __is_compare_transparent
+ _LIBCPP_HIDE_FROM_ABI iterator find(const _Kp& __x) {
+ return __find_impl(*this, __x);
+ }
+
+ template <class _Kp>
+ requires __is_compare_transparent
+ _LIBCPP_HIDE_FROM_ABI const_iterator find(const _Kp& __x) const {
+ return __find_impl(*this, __x);
+ }
+
+ _LIBCPP_HIDE_FROM_ABI size_type count(const key_type& __x) const { return contains(__x) ? 1 : 0; }
+
+ template <class _Kp>
+ requires __is_compare_transparent
+ _LIBCPP_HIDE_FROM_ABI size_type count(const _Kp& __x) const {
+ auto [__first, __last] = __equal_range_return_key_iter(*this, __x);
+ return __last - __first;
+ }
+
+ _LIBCPP_HIDE_FROM_ABI bool contains(const key_type& __x) const { return find(__x) != end(); }
+
+ template <class _Kp>
+ _LIBCPP_HIDE_FROM_ABI bool contains(const _Kp& __x) const {
+ return find(__x) != end();
+ }
+
+ _LIBCPP_HIDE_FROM_ABI iterator lower_bound(const key_type& __x) { return __lower_bound_impl<iterator>(*this, __x); }
+
+ _LIBCPP_HIDE_FROM_ABI const_iterator lower_bound(const key_type& __x) const {
+ return __lower_bound_impl<const_iterator>(*this, __x);
+ }
+
+ template <class _Kp>
+ requires __is_compare_transparent
+ _LIBCPP_HIDE_FROM_ABI iterator lower_bound(const _Kp& __x) {
+ return __lower_bound_impl<iterator>(*this, __x);
+ }
+
+ template <class _Kp>
+ requires __is_compare_transparent
+ _LIBCPP_HIDE_FROM_ABI const_iterator lower_bound(const _Kp& __x) const {
+ return __lower_bound_impl<const_iterator>(*this, __x);
+ }
+
+ _LIBCPP_HIDE_FROM_ABI iterator upper_bound(const key_type& __x) { return __upper_bound_impl<iterator>(*this, __x); }
+
+ _LIBCPP_HIDE_FROM_ABI const_iterator upper_bound(const key_type& __x) const {
+ return __upper_bound_impl<const_iterator>(*this, __x);
+ }
+
+ template <class _Kp>
+ requires __is_compare_transparent
+ _LIBCPP_HIDE_FROM_ABI iterator upper_bound(const _Kp& __x) {
+ return __upper_bound_impl<iterator>(*this, __x);
+ }
+
+ template <class _Kp>
+ requires __is_compare_transparent
+ _LIBCPP_HIDE_FROM_ABI const_iterator upper_bound(const _Kp& __x) const {
+ return __upper_bound_impl<iterator>(*this, __x);
+ }
+
+ _LIBCPP_HIDE_FROM_ABI pair<iterator, iterator> equal_range(const key_type& __x) {
+ return __equal_range_impl(*this, __x);
+ }
+
+ _LIBCPP_HIDE_FROM_ABI pair<const_iterator, const_iterator> equal_range(const key_type& __x) const {
+ return __equal_range_impl(*this, __x);
+ }
+
+ template <class _Kp>
+ requires __is_compare_transparent
+ _LIBCPP_HIDE_FROM_ABI pair<iterator, iterator> equal_range(const _Kp& __x) {
+ return __equal_range_impl(*this, __x);
+ }
+ template <class _Kp>
+ requires __is_compare_transparent
+ _LIBCPP_HIDE_FROM_ABI pair<const_iterator, const_iterator> equal_range(const _Kp& __x) const {
+ return __equal_range_impl(*this, __x);
+ }
+
+ friend _LIBCPP_HIDE_FROM_ABI bool operator==(const flat_map& __x, const flat_map& __y) {
+ return ranges::equal(__x, __y);
+ }
+
+ friend _LIBCPP_HIDE_FROM_ABI auto operator<=>(const flat_map& __x, const flat_map& __y) {
+ return std::lexicographical_compare_three_way(
+ __x.begin(), __x.end(), __y.begin(), __y.end(), std::__synth_three_way);
+ }
+
+ friend _LIBCPP_HIDE_FROM_ABI void swap(flat_map& __x, flat_map& __y) noexcept { __x.swap(__y); }
+
+private:
+ struct __ctor_uses_allocator_tag {
+ explicit __ctor_uses_allocator_tag() = default;
+ };
+ struct __ctor_uses_allocator_empty_tag {
+ explicit __ctor_uses_allocator_empty_tag() = default;
+ };
+ _LIBCPP_HIDE_FROM_ABI void __sort_and_unique() {
+ auto __zv = ranges::views::zip(__containers_.keys, __containers_.values);
+ ranges::stable_sort(__zv, __compare_, [](const auto& __p) -> decltype(auto) { return std::get<0>(__p); });
+ auto __it = ranges::unique(__zv, __key_equiv(__compare_)).begin();
+ auto __dist = ranges::distance(__zv.begin(), __it);
+ __containers_.keys.erase(__containers_.keys.begin() + __dist, __containers_.keys.end());
+ __containers_.values.erase(__containers_.values.begin() + __dist, __containers_.values.end());
+ }
+
+ template <class _Allocator, class _KeyCont, class _MappedCont, class... _CompArg>
+ _LIBCPP_HIDE_FROM_ABI
+ flat_map(__ctor_uses_allocator_tag,
+ const _Allocator& __alloc,
+ _KeyCont&& __key_cont,
+ _MappedCont&& __mapped_cont,
+ _CompArg&&... __comp)
+ : __containers_{.keys = std::make_obj_using_allocator<key_container_type>(
+ __alloc, std::forward<_KeyCont>(__key_cont)),
+ .values = std::make_obj_using_allocator<mapped_container_type>(
+ __alloc, std::forward<_MappedCont>(__mapped_cont))},
+ __compare_(std::forward<_CompArg>(__comp)...) {}
+
+ template <class _Allocator, class... _CompArg>
+ _LIBCPP_HIDE_FROM_ABI flat_map(__ctor_uses_allocator_empty_tag, const _Allocator& __alloc, _CompArg&&... __comp)
+ : __containers_{.keys = std::make_obj_using_allocator<key_container_type>(__alloc),
+ .values = std::make_obj_using_allocator<mapped_container_type>(__alloc)},
+ __compare_(std::forward<_CompArg>(__comp)...) {}
+
+ template <class _Self, class _Kp>
+ _LIBCPP_HIDE_FROM_ABI static auto __find_impl(_Self&& __self, const _Kp& __key) {
+ auto __it = __self.lower_bound(__key);
+ auto __last = __self.end();
+ if (__it == __last || __self.__compare_(__key, __it->first)) {
+ return __last;
+ }
+ return __it;
+ }
+
+ template <class _Self>
+ _LIBCPP_HIDE_FROM_ABI static auto __equal_range_return_key_iter(_Self&& __self, const _Key& __key) {
+ auto __it = ranges::lower_bound(__self.__containers_.keys, __key, __self.__compare_);
+ auto __last = __self.__containers_.keys.end();
+ if (__it == __last || __self.__compare_(__key, *__it)) {
+ return std::make_pair(__it, __it);
+ }
+ return std::make_pair(__it, std::next(__it));
+ }
+
+ template <class _Self, class _Kp>
+ _LIBCPP_HIDE_FROM_ABI static auto __equal_range_return_key_iter(_Self&& __self, const _Kp& __key) {
+ // if the comparator gives different results between Key(__x) < key2 and __x < key2,
+ // the container might have duplicates w.r.t to _Kp < Key
+ // TODO: this is the case in Author's test case, but do we really want to support it?
+ auto __first_not_smaller = ranges::lower_bound(__self.__containers_.keys, __key, __self.__compare_);
+ auto __first_bigger =
+ std::ranges::partition_point(__first_not_smaller, __self.__containers_.keys.end(), [&](const auto& __ele) {
+ return !std::invoke(__self.__compare_, __key, __ele);
+ });
+ return std::make_pair(std::move(__first_not_smaller), std::move(__first_bigger));
+ }
+
+ template <class _Self, class _Kp>
+ _LIBCPP_HIDE_FROM_ABI static auto __equal_range_impl(_Self&& __self, const _Kp& __key) {
+ // if the comparator gives different results between Key(__x) < key2 and __x < key2,
+ // the container might have duplicates w.r.t to _Kp < Key
+ // TODO: this is the case in Author's test case, but do we really want to support it?
+ auto [__first_not_smaller_key_iter, __first_bigger_key_iter] = __equal_range_return_key_iter(__self, __key);
+
+ const auto __make_mapped_iter = [&](const auto& __key_iter) {
+ return __self.__containers_.values.begin() +
+ static_cast<ranges::range_difference_t<mapped_container_type>>(
+ ranges::distance(__self.__containers_.keys.begin(), __key_iter));
+ };
+
+ using __iterator_type = ranges::iterator_t<decltype(__self)>;
+ return std::make_pair(
+ __iterator_type(__first_not_smaller_key_iter, __make_mapped_iter(__first_not_smaller_key_iter)),
+ __iterator_type(__first_bigger_key_iter, __make_mapped_iter(__first_bigger_key_iter)));
+ }
+
+ template <class _Res, class _Self, class _Kp>
+ _LIBCPP_HIDE_FROM_ABI static _Res __lower_bound_impl(_Self&& __self, _Kp& __x) {
+ return __binary_search_impl<_Res>(ranges::lower_bound, __self, __x);
+ }
+
+ template <class _Res, class _Self, class _Kp>
+ _LIBCPP_HIDE_FROM_ABI static _Res __upper_bound_impl(_Self&& __self, _Kp& __x) {
+ return __binary_search_impl<_Res>(ranges::upper_bound, __self, __x);
+ }
+
+ template <class _Kp>
+ _LIBCPP_HIDE_FROM_ABI bool __is_hint_correct(const_iterator __hint, _Kp&& __key) {
+ if (__hint != cbegin() && !__compare_(std::prev(__hint)->first, __key)) {
+ return false;
+ }
+ if (__hint != cend() && __compare_(__hint->first, __key)) {
+ return false;
+ }
+ return true;
+ }
+
+ template <class _Res, class _Fn, class _Self, class _Kp>
+ _LIBCPP_HIDE_FROM_ABI static _Res __binary_search_impl(_Fn __search_fn, _Self&& __self, _Kp& __x) {
+ auto __key_iter = __search_fn(__self.__containers_.keys, __x, __self.__compare_);
+ auto __mapped_iter =
+ __self.__containers_.values.begin() +
+ static_cast<ranges::range_difference_t<mapped_container_type>>(
+ ranges::distance(__self.__containers_.keys.begin(), __key_iter));
+
+ return _Res(std::move(__key_iter), std::move(__mapped_iter));
+ }
+
+ _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> __binary_search_emplace_impl(std::pair<key_type, mapped_type>&& __pair) {
+ if (auto __it = lower_bound(__pair.first); __it == end() || __compare_(__pair.first, (*__it).first)) {
+ return pair<iterator, bool>(__emplace_impl(__it, std::move(__pair)), true);
+ } else {
+ return pair<iterator, bool>(std::move(__it), false);
+ }
+ }
+
+ template <class _Iter>
+ _LIBCPP_HIDE_FROM_ABI iterator __emplace_impl(_Iter&& __it, std::pair<key_type, mapped_type>&& __pair) {
+ return __try_emplace_impl(__it.__key_iter_, __it.__mapped_iter_, std::move(__pair.first), std::move(__pair.second));
+ }
+
+ template <class _KeyArg, class... _MArgs>
+ _LIBCPP_HIDE_FROM_ABI pair<iterator, bool>
+ __binary_search_try_emplace_impl(_KeyArg&& __key, _MArgs&&... __mapped_args) {
+ auto __key_it = ranges::lower_bound(__containers_.keys, __key, __compare_);
+ auto __mapped_it = __containers_.values.begin() + ranges::distance(__containers_.keys.begin(), __key_it);
+
+ if (__key_it == __containers_.keys.end() || __compare_(__key, *__key_it)) {
+ return pair<iterator, bool>(
+ __try_emplace_impl(std::move(__key_it),
+ std::move(__mapped_it),
+ std::forward<_KeyArg>(__key),
+ std::forward<_MArgs>(__mapped_args)...),
+ true);
+ } else {
+ return pair<iterator, bool>(iterator(std::move(__key_it), std::move(__mapped_it)), false);
+ }
+ }
+
+ template <class _Kp, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI iterator try_emplace_hint_impl(const_iterator __hint, _Kp&& __key, _Args&&... __args) {
+ if (__is_hint_correct(__hint, __key)) {
+ if (__compare_(__key, __hint->first)) {
+ return __try_emplace_impl(
+ __hint.__key_iter_, __hint.__mapped_iter_, std::forward<_Kp>(__key), std::forward<_Args>(__args)...);
+ } else {
+ // key equals
+ auto __dist = __hint - cbegin();
+ return iterator(__containers_.keys.begin() + __dist, __containers_.values.begin() + __dist);
+ }
+ } else {
+ __binary_search_try_emplace_impl(std::forward<_Kp>(__key), std::forward<_Args>(__args)...).first;
+ }
+ }
+
+ template <class _Container>
+ static consteval bool __emplacement_has_strong_exception_safety_guarantee() {
+ // [container.reqmts] If an exception is thrown by an insert() or emplace() function while inserting a single
+ // element, that function has no effects. Except it is specified otherwise in the container...
+
+ // according to http://eel.is/c++draft/deque.modifiers#3 and http://eel.is/c++draft/vector.modifiers#2,
+ // the only exceptions that can cause side effects on single emplacement are by move constructors of
+ // non-Cpp17CopyInsertable T
+
+ using _Element = typename _Container::value_type;
+ if constexpr (is_nothrow_move_constructible_v<_Element>) {
+ return false;
+ } else {
+ if constexpr (requires { typename _Container::allocator_type; }) {
+ return !__is_cpp17_copy_insertable<typename _Container::allocator_type>::value;
+ } else {
+ return !__is_cpp17_copy_insertable<std::allocator<_Element>>::value;
+ }
+ }
+ }
+
+ struct __flat_map_restore_error : runtime_error {
+ using runtime_error::runtime_error;
+ };
+
+ template <class _Container, class _Iter, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI ranges::iterator_t<_Container>
+ __safe_emplace(_Container& __container, _Iter&& __iter, _Args&&... __args) {
+ if constexpr (__emplacement_has_strong_exception_safety_guarantee<_Container>()) {
+ // just let the exception be thrown as the container is still in its original state on exception
+ return __container.emplace(__iter, std::forward<_Args>(__args)...);
+ } else {
+# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
+ try {
+# endif // _LIBCPP_HAS_NO_EXCEPTIONS
+ return __container.emplace(__iter, std::forward<_Args>(__args)...);
+# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
+ } catch (const exception& __ex) {
+ // The container might be in some unknown state and we can't get flat_map into consistent state
+ // because we have two containers. The only possible solution is to clear them out
+ clear();
+ throw __flat_map_restore_error(
+ std::string("flat_map::emplace: Emplacement on the underlying container has failed and has side effect. "
+ "Unable to restore flat_map to previous state. Clear out the containers to make the two "
+ "containers consistent. Reason: ") +
+ __ex.what());
+ } catch (...) {
+ // The container might be in some unknown state and we can't get flat_map into consistent state
+ // because we have two containers. The only possible solution is to clear them out
+ clear();
+ throw __flat_map_restore_error(
+ "flat_map::emplace: Emplacement on the underlying container has failed and has side effect. "
+ "Unable to restore flat_map to previous state. Clear out the containers to make the two "
+ "containers consistent.");
+ }
+# endif // _LIBCPP_HAS_NO_EXCEPTIONS
+ }
+ }
+
+ template <class _Container, class _Iter>
+ _LIBCPP_HIDE_FROM_ABI auto __safe_erase(_Container& __container, _Iter&& __iter) {
+ // [container.reqmts] No erase(), clear(), pop_back() or pop_front() function throws an exception,
+ // except that there are exceptional cases
+
+ // http://eel.is/c++draft/deque.modifiers#5
+ // http://eel.is/c++draft/vector.modifiers#4
+
+# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
+ try {
+# endif // _LIBCPP_HAS_NO_EXCEPTIONS
+ return __container.erase(__iter);
+# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
+ } catch (const exception& __ex) {
+ // The container might be in some unknown state and we can't get flat_map into consistent state
+ // because we have two containers. The only possible solution is to clear them out
+ clear();
+ throw __flat_map_restore_error(
+ std::string("flat_map: Erasing on the underlying container has failed. "
+ "Unable to restore flat_map to previous state. Clear out the containers to make the two "
+ "containers consistent. Reason: ") +
+ __ex.what());
+ } catch (...) {
+ // The container might be in some unknown state and we can't get flat_map into consistent state
+ // because we have two containers. The only possible solution is to clear them out
+ clear();
+ throw __flat_map_restore_error(
+ "flat_map: Erasing on the underlying container has failed. "
+ "Unable to restore flat_map to previous state. Clear out the containers to make the two "
+ "containers consistent.");
+ }
+# endif // _LIBCPP_HAS_NO_EXCEPTIONS
+ }
+
+ template <class _IterK, class _IterM, class _KeyArg, class... _MArgs>
+ _LIBCPP_HIDE_FROM_ABI iterator
+ __try_emplace_impl(_IterK&& __it_key, _IterM&& __it_mapped, _KeyArg&& __key, _MArgs&&... __mapped_args) {
----------------
ldionne wrote:
>From our live review just now:
```c++
template <class _IterK, class _IterM, class _KeyArg, class... _MArgs>
_LIBCPP_HIDE_FROM_ABI iterator
__try_emplace_impl(_IterK&& __it_key, _IterM&& __it_mapped, _KeyArg&& __key, _MArgs&&... __mapped_args) {
auto __on_key_failed = std::__make_exception_guard([&]() noexcept {
if constexpr (__emplacement_has_strong_exception_safety_guarantee<_KeyContainer>()) {
// Nothing to roll back!
} else {
// we need to clear both because we don't know the state of our keys anymore
clear() /* noexcept */;
}
});
auto __key_it = __containers_.keys.emplace(__it_key, std::forward<_KeyArg>(__key));
__on_key_failed.__complete();
auto __on_value_failed = std::__make_exception_guard([&]() noexcept {
if constexpr (!__emplacement_has_strong_exception_safety_guarantee<_ValueContainer>()) {
// we need to clear both because we don't know the state of our values anymore
clear() /* noexcept */;
} else {
// In this case, we know the values are just like before we attempted emplacement,
// and we also know that the keys have been emplaced successfully. Just roll back the keys.
try {
__containers_.keys.erase(__key_it);
} catch (...) {
// Now things are funky for real. We're failing to rollback the keys.
// Just give up and clear the whole thing.
//
// Also, swallow the exception that happened during the rollback and let the
// original value-emplacement exception propagate normally.
clear() /* noexcept */;
}
}
});
auto __mapped_it = __containers_.values.emplace(__it_mapped, std::forward<_MArgs>(__mapped_args)...);
__on_value_failed.__complete();
return iterator(std::move(__key_it), std::move(__mapped_it));
}
```
https://github.com/llvm/llvm-project/pull/98643
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