On Mon, 30 Sep 2024, Patrick Palka wrote:
> This implements the C++23 container adaptors std::flat_map and
> std::flat_multimap from P0429R9. The implementation is shared
> as much as possible between the two adaptors via a common base
> class that's parameterized according to key uniqueness.
>
> The main known issues are:
>
> * the range insert() overload exceeds its complexity requirements
> since an idiomatic efficient implementation needs a non-buggy
> ranges::inplace_merge
> * exception safety is likely incomplete/buggy
> * unimplemented from_range_t constructors and insert_range function
> * the main workhorse function _M_try_emplace is probably buggy
> buggy wrt its handling of the hint parameter and could be simplified
> * more extensive testcases are a WIP
>
> The iterator type is encoded as a {pointer, index} pair instead of an
> {iterator, iterator} pair. I'm not sure which encoding is preferable?
> It seems the latter would allow for better debuggability when the
> underlying iterators are debug iterators.
Here's v2 which adds somewhat more tests and uses the std:: algos
instead of ranges:: algos where possible, along with some other
very minor cleanups.
-- >8 --
libstdc++-v3/ChangeLog:
* include/Makefile.am: Add new header <flat_map>.
* include/Makefile.in: Regenerate.
* include/bits/stl_function.h (__transparent_comparator): Define.
* include/bits/utility.h (sorted_unique_t): Define for C++23.
(sorted_unique): Likewise.
(sorted_equivalent_t): Likewise.
(sorted_equivalent): Likewise.
* include/bits/version.def (flat_map): Define.
* include/bits/version.h: Regenerate.
* include/std/flat_map: New file.
* testsuite/23_containers/flat_map/1.cc: New test.
* testsuite/23_containers/flat_multimap/1.cc: New test.
---
libstdc++-v3/include/Makefile.am | 1 +
libstdc++-v3/include/Makefile.in | 1 +
libstdc++-v3/include/bits/stl_function.h | 6 +
libstdc++-v3/include/bits/utility.h | 8 +
libstdc++-v3/include/bits/version.def | 8 +
libstdc++-v3/include/bits/version.h | 10 +
libstdc++-v3/include/std/flat_map | 1475 +++++++++++++++++
.../testsuite/23_containers/flat_map/1.cc | 123 ++
.../23_containers/flat_multimap/1.cc | 106 ++
9 files changed, 1738 insertions(+)
create mode 100644 libstdc++-v3/include/std/flat_map
create mode 100644 libstdc++-v3/testsuite/23_containers/flat_map/1.cc
create mode 100644 libstdc++-v3/testsuite/23_containers/flat_multimap/1.cc
diff --git a/libstdc++-v3/include/Makefile.am b/libstdc++-v3/include/Makefile.am
index 422a0f4bd0a..632bbafa63e 100644
--- a/libstdc++-v3/include/Makefile.am
+++ b/libstdc++-v3/include/Makefile.am
@@ -70,6 +70,7 @@ std_headers = \
${std_srcdir}/deque \
${std_srcdir}/execution \
${std_srcdir}/filesystem \
+ ${std_srcdir}/flat_map \
${std_srcdir}/format \
${std_srcdir}/forward_list \
${std_srcdir}/fstream \
diff --git a/libstdc++-v3/include/Makefile.in b/libstdc++-v3/include/Makefile.in
index 9fd4ab4848c..1ac963c4415 100644
--- a/libstdc++-v3/include/Makefile.in
+++ b/libstdc++-v3/include/Makefile.in
@@ -426,6 +426,7 @@ std_freestanding = \
@GLIBCXX_HOSTED_TRUE@ ${std_srcdir}/deque \
@GLIBCXX_HOSTED_TRUE@ ${std_srcdir}/execution \
@GLIBCXX_HOSTED_TRUE@ ${std_srcdir}/filesystem \
+@GLIBCXX_HOSTED_TRUE@ ${std_srcdir}/flat_map \
@GLIBCXX_HOSTED_TRUE@ ${std_srcdir}/format \
@GLIBCXX_HOSTED_TRUE@ ${std_srcdir}/forward_list \
@GLIBCXX_HOSTED_TRUE@ ${std_srcdir}/fstream \
diff --git a/libstdc++-v3/include/bits/stl_function.h
b/libstdc++-v3/include/bits/stl_function.h
index c9123ccecae..c579ba9f47b 100644
--- a/libstdc++-v3/include/bits/stl_function.h
+++ b/libstdc++-v3/include/bits/stl_function.h
@@ -1426,6 +1426,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Func, typename _SfinaeType>
using __has_is_transparent_t
= typename __has_is_transparent<_Func, _SfinaeType>::type;
+
+#if __cpp_concepts
+ template<typename _Func>
+ concept __transparent_comparator
+ = requires { typename _Func::is_transparent; };
+#endif
#endif
_GLIBCXX_END_NAMESPACE_VERSION
diff --git a/libstdc++-v3/include/bits/utility.h
b/libstdc++-v3/include/bits/utility.h
index 4a6c16dc2e0..9e10ce2cb1c 100644
--- a/libstdc++-v3/include/bits/utility.h
+++ b/libstdc++-v3/include/bits/utility.h
@@ -308,6 +308,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
*/
_GLIBCXX17_INLINE constexpr _Swallow_assign ignore{};
+#if __glibcxx_flat_map || __glibcxx_flat_set // >= C++23
+ struct sorted_unique_t { explicit sorted_unique_t() = default; };
+ inline constexpr sorted_unique_t sorted_unique{};
+
+ struct sorted_equivalent_t { explicit sorted_equivalent_t() = default; };
+ inline constexpr sorted_equivalent_t sorted_equivalent{};
+#endif
+
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
diff --git a/libstdc++-v3/include/bits/version.def
b/libstdc++-v3/include/bits/version.def
index 4fa820a5a4a..6f1958ac705 100644
--- a/libstdc++-v3/include/bits/version.def
+++ b/libstdc++-v3/include/bits/version.def
@@ -1658,6 +1658,14 @@ ftms = {
};
};
+ftms = {
+ name = flat_map;
+ values = {
+ v = 202207;
+ cxxmin = 23;
+ };
+};
+
ftms = {
name = formatters;
values = {
diff --git a/libstdc++-v3/include/bits/version.h
b/libstdc++-v3/include/bits/version.h
index fdbee8161d9..ecead3edb26 100644
--- a/libstdc++-v3/include/bits/version.h
+++ b/libstdc++-v3/include/bits/version.h
@@ -1830,6 +1830,16 @@
#endif /* !defined(__cpp_lib_adaptor_iterator_pair_constructor) &&
defined(__glibcxx_want_adaptor_iterator_pair_constructor) */
#undef __glibcxx_want_adaptor_iterator_pair_constructor
+#if !defined(__cpp_lib_flat_map)
+# if (__cplusplus >= 202100L)
+# define __glibcxx_flat_map 202207L
+# if defined(__glibcxx_want_all) || defined(__glibcxx_want_flat_map)
+# define __cpp_lib_flat_map 202207L
+# endif
+# endif
+#endif /* !defined(__cpp_lib_flat_map) && defined(__glibcxx_want_flat_map) */
+#undef __glibcxx_want_flat_map
+
#if !defined(__cpp_lib_formatters)
# if (__cplusplus >= 202100L) && _GLIBCXX_HOSTED
# define __glibcxx_formatters 202302L
diff --git a/libstdc++-v3/include/std/flat_map
b/libstdc++-v3/include/std/flat_map
new file mode 100644
index 00000000000..ff653e949db
--- /dev/null
+++ b/libstdc++-v3/include/std/flat_map
@@ -0,0 +1,1475 @@
+// <flat_map> -*- C++ -*-
+
+// Copyright The GNU Toolchain Authors.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+// <http://www.gnu.org/licenses/>.
+
+/** @file include/flat_map
+ * This is a Standard C++ Library header.
+ */
+
+#ifndef _GLIBCXX_FLAT_MAP
+#define _GLIBCXX_FLAT_MAP 1
+
+#ifdef _GLIBCXX_SYSHDR
+#pragma GCC system_header
+#endif
+
+#define __glibcxx_want_flat_map
+#include <bits/version.h>
+
+#ifdef __cpp_lib_flat_map // >= C++23
+
+#include <compare>
+#include <initializer_list>
+
+#include <algorithm>
+#include <exception>
+#include <functional>
+#include <optional>
+#include <ranges>
+#include <type_traits>
+#include <vector>
+#include <bits/functexcept.h>
+#include <bits/stl_function.h> // std::less
+#include <bits/stl_pair.h>
+
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+ template<typename _Key, typename _Tp, typename _Compare,
+ typename _KeyContainer, typename _MappedContainer>
+ class flat_map;
+
+ template<typename _Key, typename _Tp, typename _Compare,
+ typename _KeyContainer, typename _MappedContainer>
+ class flat_multimap;
+
+ template<typename _Key, typename _Tp, typename _Compare,
+ typename _KeyContainer, typename _MappedContainer, bool _Multi>
+ class _Flat_map_impl
+ {
+ static_assert(is_same_v<_Key, typename _KeyContainer::value_type>);
+ static_assert(is_same_v<_Tp, typename _MappedContainer::value_type>);
+
+ static_assert(is_nothrow_swappable_v<_KeyContainer>);
+ static_assert(is_nothrow_swappable_v<_MappedContainer>);
+
+ using _Derived = __conditional_t<_Multi,
+ flat_multimap<_Key, _Tp, _Compare,
+ _KeyContainer,
_MappedContainer>,
+ flat_map<_Key, _Tp, _Compare,
+ _KeyContainer,
_MappedContainer>>;
+ using __sorted_t = __conditional_t<_Multi, sorted_equivalent_t,
sorted_unique_t>;
+
+ public:
+ template<bool _Const> struct _Iterator;
+
+ using key_type = _Key;
+ using mapped_type = _Tp;
+ using value_type = pair<key_type, mapped_type>;
+ using key_compare = _Compare;
+ using reference = pair<const key_type&, mapped_type&>;
+ using const_reference = pair<const key_type&, const
mapped_type&>;
+ using size_type = size_t;
+ using difference_type = ptrdiff_t;
+ using iterator = _Iterator<false>;
+ using const_iterator = _Iterator<true>;
+ 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;
+
+ private:
+ using __emplace_result_t = __conditional_t<_Multi, iterator,
pair<iterator, bool>>;
+
+ public:
+ class value_compare
+ {
+ [[no_unique_address]] key_compare _M_comp;
+ value_compare(key_compare __c) : _M_comp(__c) { }
+
+ public:
+ bool
+ operator()(const_reference __x, const_reference __y) const
+ { return _M_comp(__x.first, __y.first); }
+
+ friend _Flat_map_impl;
+ };
+
+ struct containers
+ {
+ key_container_type keys;
+ mapped_container_type values;
+ };
+
+ // constructors
+ _Flat_map_impl() : _Flat_map_impl(key_compare()) { }
+
+ explicit
+ _Flat_map_impl(const key_compare& __comp)
+ : _M_cont(), _M_comp(__comp)
+ { }
+
+ _Flat_map_impl(key_container_type __key_cont,
+ mapped_container_type __mapped_cont,
+ const key_compare& __comp = key_compare())
+ : _M_cont(std::move(__key_cont), std::move(__mapped_cont)),
_M_comp(__comp)
+ {
+ __glibcxx_assert(_M_cont.keys.size() == _M_cont.values.size());
+ _M_sort_uniq();
+ }
+
+ _Flat_map_impl(__sorted_t,
+ key_container_type __key_cont,
+ mapped_container_type __mapped_cont,
+ const key_compare& __comp = key_compare())
+ : _M_cont(std::move(__key_cont), std::move(__mapped_cont)),
_M_comp(__comp)
+ { __glibcxx_assert(_M_cont.keys.size() == _M_cont.values.size()); }
+
+ template<typename _InputIterator,
+ typename = _RequireInputIter<_InputIterator>>
+ _Flat_map_impl(_InputIterator __first, _InputIterator __last,
+ const key_compare& __comp = key_compare())
+ : _M_cont(), _M_comp(__comp)
+ { insert(__first, __last); }
+
+ template<typename _InputIterator,
+ typename = _RequireInputIter<_InputIterator>>
+ _Flat_map_impl(__sorted_t __s,
+ _InputIterator __first, _InputIterator __last,
+ const key_compare& __comp = key_compare())
+ : _M_cont(), _M_comp(__comp)
+ { insert(__s, __first, __last); }
+
+ // TODO: Implement from_range_t constructors.
+
+ _Flat_map_impl(initializer_list<value_type> __il,
+ const key_compare& __comp = key_compare())
+ : _Flat_map_impl(__il.begin(), __il.end(), __comp)
+ { }
+
+ _Flat_map_impl(__sorted_t __s,
+ initializer_list<value_type> __il,
+ const key_compare& __comp = key_compare())
+ : _Flat_map_impl(__s, __il.begin(), __il.end(), __comp)
+ { }
+
+ // constructors with allocators
+
+ template<typename _Alloc>
+ explicit
+ _Flat_map_impl(const _Alloc& __a)
+ : _Flat_map_impl(key_compare(), __a)
+ { }
+
+ template<typename _Alloc>
+ _Flat_map_impl(const key_compare& __comp, const _Alloc& __a)
+ : _M_cont(std::make_obj_using_allocator<key_container_type>(__a),
+ std::make_obj_using_allocator<mapped_container_type>(__a)),
+ _M_comp(__comp)
+ { }
+
+ template<typename _Alloc>
+ _Flat_map_impl(const key_container_type& __key_cont,
+ const mapped_container_type& __mapped_cont,
+ const _Alloc& __a)
+ : _Flat_map_impl(__key_cont, __mapped_cont, key_compare(), __a)
+ { }
+
+ template<typename _Alloc>
+ _Flat_map_impl(const key_container_type& __key_cont,
+ const mapped_container_type& __mapped_cont,
+ const key_compare& __comp,
+ const _Alloc& __a)
+ : _M_cont(std::make_obj_using_allocator<key_container_type>(__a,
__key_cont),
+ std::make_obj_using_allocator<mapped_container_type>(__a,
__mapped_cont)),
+ _M_comp(__comp)
+ {
+ __glibcxx_assert(_M_cont.keys.size() == _M_cont.values.size());
+ _M_sort_uniq();
+ }
+
+ template<typename _Alloc>
+ _Flat_map_impl(__sorted_t __s,
+ const key_container_type& __key_cont,
+ const mapped_container_type& __mapped_cont,
+ const _Alloc& __a)
+ : _Flat_map_impl(__s, __key_cont, __mapped_cont, key_compare(), __a)
+ { }
+
+ template<typename _Alloc>
+ _Flat_map_impl(__sorted_t __s,
+ const key_container_type& __key_cont,
+ const mapped_container_type& __mapped_cont,
+ const key_compare& __comp,
+ const _Alloc& __a)
+ : _M_comp(__comp),
+ _M_cont(std::make_obj_using_allocator<key_container_type>(__a,
__key_cont),
+ std::make_obj_using_allocator<mapped_container_type>(__a,
__mapped_cont))
+ { __glibcxx_assert(_M_cont.keys.size() == _M_cont.values.size()); }
+
+ template<typename _Alloc>
+ _Flat_map_impl(const _Derived& __x, const _Alloc& __a)
+ : _M_comp(__x._M_comp),
+ _M_cont(std::make_obj_using_allocator<containers>(__a, __x._M_cont))
+ { }
+
+ template<typename _Alloc>
+ _Flat_map_impl(_Derived&& __x, const _Alloc& __a)
+ : _M_comp(__x._M_comp),
+ _M_cont(std::make_obj_using_allocator<containers>(__a,
std::move(__x._M_cont)))
+ { }
+
+ template<typename _InputIterator, typename _Alloc,
+ typename = _RequireInputIter<_InputIterator>>
+ _Flat_map_impl(_InputIterator __first, _InputIterator __last,
+ const _Alloc& __a)
+ : _Flat_map_impl(std::move(__first), std::move(__last), key_compare(),
__a)
+ { }
+
+ template<typename _InputIterator, typename _Alloc,
+ typename = _RequireInputIter<_InputIterator>>
+ _Flat_map_impl(_InputIterator __first, _InputIterator __last,
+ const key_compare& __comp,
+ const _Alloc& __a)
+ : _Flat_map_impl(__comp, __a)
+ { insert(__first, __last); }
+
+ template<typename _InputIterator, typename _Alloc,
+ typename = _RequireInputIter<_InputIterator>>
+ _Flat_map_impl(__sorted_t __s,
+ _InputIterator __first, _InputIterator __last,
+ const _Alloc& __a)
+ : _Flat_map_impl(__s, std::move(__first), std::move(__last),
key_compare(), __a)
+ { }
+
+ template<typename _InputIterator, typename _Alloc,
+ typename = _RequireInputIter<_InputIterator>>
+ _Flat_map_impl(__sorted_t __s,
+ _InputIterator __first, _InputIterator __last,
+ const key_compare& __comp,
+ const _Alloc& __a)
+ : _Flat_map_impl(__comp, __a)
+ { insert(__s, __first, __last); }
+
+ // TODO: Implement allocator-aware from_range_t constructors.
+
+ template<typename _Alloc>
+ _Flat_map_impl(initializer_list<value_type> __il,
+ const _Alloc& __a)
+ : _Flat_map_impl(__il, key_compare(), __a)
+ { }
+
+ template<typename _Alloc>
+ _Flat_map_impl(initializer_list<value_type> __il,
+ const key_compare& __comp,
+ const _Alloc& __a)
+ : _Flat_map_impl(__il.begin(), __il.end(), __comp, __a)
+ { }
+
+ template<typename _Alloc>
+ _Flat_map_impl(__sorted_t __s,
+ initializer_list<value_type> __il,
+ const _Alloc& __a)
+ : _Flat_map_impl(__s, __il.begin(), __il.end(), key_compare(), __a)
+ { }
+
+ template<typename _Alloc>
+ _Flat_map_impl(__sorted_t __s,
+ initializer_list<value_type> __il,
+ const key_compare& __comp,
+ const _Alloc& __a)
+ : _Flat_map_impl(__s, __il.begin(), __il.end(), __comp, __a)
+ { }
+
+ _Derived&
+ operator=(initializer_list<value_type> __il)
+ {
+ clear();
+ insert(__il);
+ return static_cast<_Derived&>(*this);
+ }
+
+ // iterators
+ iterator
+ begin() noexcept
+ { return {this, _M_cont.keys.cbegin()}; }
+
+ const_iterator
+ begin() const noexcept
+ { return {this, _M_cont.keys.cbegin()}; }
+
+ iterator
+ end() noexcept
+ { return {this, _M_cont.keys.cend()}; }
+
+ const_iterator
+ end() const noexcept
+ { return {this, _M_cont.keys.cend()}; }
+
+ reverse_iterator
+ rbegin() noexcept
+ { return reverse_iterator(end()); }
+
+ const_reverse_iterator
+ rbegin() const noexcept
+ { return const_reverse_iterator(end()); }
+
+ reverse_iterator
+ rend() noexcept
+ { return reverse_iterator(begin()); }
+
+ const_reverse_iterator
+ rend() const noexcept
+ { return const_reverse_iterator(begin()); }
+
+ const_iterator
+ cbegin() const noexcept
+ { return {this, _M_cont.keys.cbegin()}; }
+
+ const_iterator
+ cend() const noexcept
+ { return {this, _M_cont.keys.cend()}; }
+
+ const_reverse_iterator
+ crbegin() const noexcept
+ { return const_reverse_iterator(cend()); }
+
+ const_reverse_iterator
+ crend() const noexcept
+ { return const_reverse_iterator(cbegin()); }
+
+ // capacity
+ [[nodiscard]] bool
+ empty() const noexcept
+ { return _M_cont.keys.empty(); }
+
+ size_type
+ size() const noexcept
+ { return _M_cont.keys.size(); }
+
+ size_type
+ max_size() const noexcept
+ { return std::min<size_type>(keys().max_size(), values().max_size()); }
+
+ // element access
+ // operator[] and at defined directly in class flat_map only.
+
+ // modifiers
+ template<typename _Key2, typename... _Args>
+ pair<iterator, bool>
+ _M_try_emplace(optional<const_iterator> __hint, _Key2&& __k, _Args&&...
__args)
+ {
+ // TODO: Simplify and audit the hint handling.
+ typename key_container_type::iterator __key_it;
+ int __r = -1, __s = -1;
+ if (__hint.has_value()
+ && (__hint == cbegin()
+ || (__r = !_M_comp(__k, (*__hint)[-1].first))) // k >=
hint[-1]
+ && (__hint == cend()
+ || (__s = !_M_comp((*__hint)[0].first, __k)))) // k <= hint[0]
+ {
+ __key_it = _M_cont.keys.begin() + __hint->_M_index;
+ if constexpr (!_Multi)
+ if (__r == 1 && !_M_comp(__key_it[-1], __k)) // k == hint[-1]
+ return {iterator{this, __key_it - 1}, false};
+ }
+ else
+ {
+ auto __first = _M_cont.keys.begin();
+ auto __last = _M_cont.keys.end();
+ if (__r == 1) // k >= hint[-1]
+ __first += __hint->_M_index;
+ else if (__r == 0) // k < __hint[-1]
+ __last = __first + __hint->_M_index;
+ if constexpr (_Multi)
+ {
+ if (__s == 0) // hint[0] < k
+ // Insert before the leftmost equivalent key.
+ __key_it = std::lower_bound(__first, __last, __k, _M_comp);
+ else
+ // Insert after the rightmost equivalent key.
+ __key_it =
std::upper_bound(std::make_reverse_iterator(__last),
+
std::make_reverse_iterator(__first),
+ __k,
std::not_fn(_M_comp)).base();
+ }
+ else
+ __key_it = std::lower_bound(__first, __last, __k, _M_comp);
+ }
+
+ if constexpr (!_Multi)
+ if (__key_it != _M_cont.keys.end() && !_M_comp(__k, __key_it[0]))
+ return {iterator{this, __key_it}, false};
+
+ __key_it = _M_cont.keys.insert(__key_it, std::move(__k));
+ __try
+ {
+ auto __value_it = _M_cont.values.begin() + (__key_it -
_M_cont.keys.begin());
+ _M_cont.values.emplace(__value_it,
std::forward<_Args>(__args)...);
+ }
+ __catch(...)
+ {
+ _M_cont.keys.erase(__key_it);
+ __throw_exception_again;
+ }
+ return {iterator{this, __key_it}, true};
+ }
+
+ template<typename... _Args>
+ requires is_constructible_v<value_type, _Args...>
+ __emplace_result_t
+ emplace(_Args&&... __args)
+ {
+ value_type __p(std::forward<_Args>(__args)...);
+ auto __r = _M_try_emplace(nullopt, std::move(__p.first),
std::move(__p.second));
+ if constexpr (_Multi)
+ return __r.first;
+ else
+ return __r;
+ }
+
+ template<typename... _Args>
+ iterator
+ emplace_hint(const_iterator __position, _Args&&... __args)
+ {
+ value_type __p(std::forward<_Args>(__args)...);
+ return _M_try_emplace(__position, std::move(__p.first),
std::move(__p.second)).first;
+ }
+
+ __emplace_result_t
+ insert(const value_type& __x)
+ { return emplace(__x); }
+
+ __emplace_result_t
+ insert(value_type&& __x)
+ { return emplace(std::move(__x)); }
+
+ iterator
+ insert(const_iterator __position, const value_type& __x)
+ { return emplace_hint(__position, __x); }
+
+ iterator
+ insert(const_iterator __position, value_type&& __x)
+ { return emplace_hint(__position, std::move(__x)); }
+
+ template<typename _Arg>
+ requires is_constructible_v<value_type, _Arg>
+ __emplace_result_t
+ insert(_Arg&& __x)
+ { return emplace(std::forward<_Arg>(__x)); }
+
+ template<typename _Arg>
+ requires is_constructible_v<value_type, _Arg>
+ iterator
+ insert(const_iterator __position, _Arg&& __x)
+ { return emplace_hint(__position, std::forward<_Arg>(__x)); }
+
+ template<typename _InputIterator, typename =
_RequireInputIter<_InputIterator>>
+ void
+ insert(_InputIterator __first, _InputIterator __last)
+ {
+ // FIXME: This implementation fails its complexity requirements.
+ // We can't idiomatically implement an efficient version (as in the
+ // disabled code) until ranges::inplace_merge is fixed to dispatch
+ // on iterator concept instead of iterator category.
+#if 0
+ auto __n = size();
+ for (; __first != __last; ++__first)
+ {
+ value_type __value = *__first;
+ _M_cont.keys.emplace_back(std::move(__value.first));
+ _M_cont.values.emplace_back(std::move(__value.second));
+ }
+ auto __zv = views::zip(_M_cont.keys, _M_cont.values);
+ ranges::sort(__zv.begin() + __n, __zv.end(), value_comp());
+ ranges::inplace_merge(__zv.begin(), __zv.begin() + __n, __zv.end(),
value_comp());
+ if constexpr (!_Multi)
+ _M_unique();
+#else
+ for (; __first != __last; ++__first)
+ {
+ value_type __value = *__first;
+ _M_cont.keys.emplace_back(std::move(__value.first));
+ _M_cont.values.emplace_back(std::move(__value.second));
+ }
+ _M_sort_uniq();
+#endif
+ }
+
+ template<typename _InputIterator, typename =
_RequireInputIter<_InputIterator>>
+ void
+ insert(__sorted_t, _InputIterator __first, _InputIterator __last)
+ {
+ // FIXME: This implementation fails its complexity requirements; see
above.
+ insert(std::move(__first), std::move(__last));
+ }
+
+ // TODO: Implement insert_range.
+
+ void
+ insert(initializer_list<value_type> __il)
+ { insert(__il.begin(), __il.end()); }
+
+ void
+ insert(__sorted_t __s, initializer_list<value_type> __il)
+ { insert(__s, __il.begin(), __il.end()); }
+
+ containers
+ extract() &&
+ {
+ struct _Guard
+ {
+ _Guard(_Flat_map_impl* __m) : _M_m(__m) { }
+
+ ~_Guard() { _M_m->clear(); }
+
+ _Flat_map_impl* _M_m;
+ } __clear_guard = {this};
+ return {std::move(_M_cont.keys), std::move(_M_cont.values)};
+ }
+
+ void
+ replace(key_container_type&& __key_cont, mapped_container_type&&
__mapped_cont)
+ {
+ __glibcxx_assert(__key_cont.size() == __mapped_cont.size());
+ __try
+ {
+ _M_cont.keys = std::move(__key_cont);
+ _M_cont.values = std::move(__mapped_cont);
+ }
+ __catch(...)
+ {
+ clear();
+ __throw_exception_again;
+ }
+ }
+
+ // try_emplace defined directly in class flat_map only.
+ // insert_or_assign defined directly in class flat_map only.
+
+ iterator
+ erase(iterator __position)
+ { return erase(static_cast<const_iterator>(__position)); }
+
+ iterator
+ erase(const_iterator __position)
+ {
+ auto __idx = __position._M_index;
+ auto __it = _M_cont.keys.erase(_M_cont.keys.begin() + __idx);
+ _M_cont.values.erase(_M_cont.values.begin() + __idx);
+ return iterator{this, __it};
+ }
+
+ size_type
+ erase(const key_type& __x)
+ { return erase<const key_type&>(__x); }
+
+ template<typename _Key2>
+ requires same_as<remove_cvref_t<_Key2>, _Key>
+ || (__transparent_comparator<_Compare>
+ && !is_convertible_v<_Key2, iterator>
+ && !is_convertible_v<_Key2, const_iterator>)
+ size_type
+ erase(_Key2&& __x)
+ {
+ auto [__first, __last] = equal_range(std::forward<_Key2>(__x));
+ auto __n = __last - __first;
+ erase(__first, __last);
+ return __n;
+ }
+
+ iterator
+ erase(const_iterator __first, const_iterator __last)
+ {
+ auto __it = _M_cont.keys.erase(_M_cont.keys.begin() + __first._M_index,
+ _M_cont.keys.begin() + __last._M_index);
+ _M_cont.values.erase(_M_cont.values.begin() + __first._M_index,
+ _M_cont.values.begin() + __last._M_index);
+ return iterator{this, __it};
+ }
+
+ void
+ swap(_Derived& __x) noexcept
+ {
+ using std::swap;
+ swap(_M_cont, __x._M_cont);
+ swap(_M_comp, __x._M_comp);
+ }
+
+ void
+ clear() noexcept
+ {
+ _M_cont.keys.clear();
+ _M_cont.values.clear();
+ }
+
+ // observers
+ key_compare
+ key_comp() const
+ { return _M_comp; }
+
+ value_compare
+ value_comp() const
+ { return value_compare(key_comp()); }
+
+ const key_container_type&
+ keys() const noexcept
+ { return _M_cont.keys; }
+
+ const mapped_container_type&
+ values() const noexcept
+ { return _M_cont.values; }
+
+ // map operations
+ iterator
+ find(const key_type& __x)
+ { return find<key_type>(__x); }
+
+ const_iterator
+ find(const key_type& __x) const
+ { return find<key_type>(__x); }
+
+ template<typename _Key2>
+ requires same_as<_Key2, _Key> || __transparent_comparator<_Compare>
+ iterator
+ find(const _Key2& __x)
+ {
+ auto __it = lower_bound(__x);
+ if (__it != end() && !_M_comp(__x, __it->first))
+ return __it;
+ else
+ return end();
+ }
+
+ template<typename _Key2>
+ requires same_as<_Key2, _Key> || __transparent_comparator<_Compare>
+ const_iterator
+ find(const _Key2& __x) const
+ {
+ auto __it = lower_bound(__x);
+ if (__it != cend() && !_M_comp(__x, __it->first))
+ return __it;
+ else
+ return cend();
+ }
+
+ size_type
+ count(const key_type& __x) const
+ { return count<key_type>(__x); }
+
+ template<typename _Key2>
+ requires same_as<_Key2, _Key> || __transparent_comparator<_Compare>
+ size_type
+ count(const _Key2& __x) const
+ {
+ if constexpr (!_Multi && same_as<_Key2, _Key>)
+ return contains(__x);
+ else
+ {
+ auto [__first, __last] = equal_range(__x);
+ return __last - __first;
+ }
+ }
+
+ bool
+ contains(const key_type& __x) const
+ { return contains<key_type>(__x); }
+
+ template<typename _Key2>
+ requires same_as<_Key2, _Key> || __transparent_comparator<_Compare>
+ bool
+ contains(const _Key2& __x) const
+ { return find(__x) != cend(); }
+
+ iterator
+ lower_bound(const key_type& __x)
+ { return lower_bound<key_type>(__x); }
+
+ const_iterator
+ lower_bound(const key_type& __x) const
+ { return lower_bound<key_type>(__x); }
+
+ template<typename _Key2>
+ requires same_as<_Key2, _Key> || __transparent_comparator<_Compare>
+ iterator
+ lower_bound(const _Key2& __x)
+ {
+ auto __it = std::lower_bound(_M_cont.keys.begin(), _M_cont.keys.end(),
+ __x, _M_comp);
+ return {this, __it};
+ }
+
+ template<typename _Key2>
+ requires same_as<_Key2, _Key> || __transparent_comparator<_Compare>
+ const_iterator
+ lower_bound(const _Key2& __x) const
+ {
+ auto __it = std::lower_bound(_M_cont.keys.begin(), _M_cont.keys.end(),
+ __x, _M_comp);
+ return {this, __it};
+ }
+
+ iterator
+ upper_bound(const key_type& __x)
+ { return upper_bound<key_type>(__x); }
+
+ const_iterator
+ upper_bound(const key_type& __x) const
+ { return upper_bound<key_type>(__x); }
+
+ template<typename _Key2>
+ requires same_as<_Key2, _Key> || __transparent_comparator<_Compare>
+ iterator
+ upper_bound(const _Key2& __x)
+ {
+ auto __it = std::upper_bound(_M_cont.keys.begin(), _M_cont.keys.end(),
+ __x, _M_comp);
+ return {this, __it};
+ }
+
+ template<typename _Key2>
+ requires same_as<_Key2, _Key> || __transparent_comparator<_Compare>
+ const_iterator
+ upper_bound(const _Key2& __x) const
+ {
+ auto __it = std::upper_bound(_M_cont.keys.begin(), _M_cont.keys.end(),
+ __x, _M_comp);
+ return {this, __it};
+ }
+
+ pair<iterator, iterator>
+ equal_range(const key_type& __x)
+ { return equal_range<key_type>(__x); }
+
+ pair<const_iterator, const_iterator>
+ equal_range(const key_type& __x) const
+ { return equal_range<key_type>(__x); }
+
+ template<typename _Key2>
+ requires same_as<_Key2, _Key> || __transparent_comparator<_Compare>
+ pair<iterator, iterator>
+ equal_range(const _Key2& __x)
+ {
+ auto [__first, __last] = std::equal_range(_M_cont.keys.begin(),
+ _M_cont.keys.end(),
+ __x, _M_comp);
+ return {{this, __first}, {this, __last}};
+ }
+
+ template<typename _Key2>
+ requires same_as<_Key2, _Key> || __transparent_comparator<_Compare>
+ pair<const_iterator, const_iterator>
+ equal_range(const _Key2& __x) const
+ {
+ auto [__first, __last] = std::equal_range(_M_cont.keys.begin(),
+ _M_cont.keys.end(),
+ __x, _M_comp);
+ return {{this, __first}, {this, __last}};
+ }
+
+ friend bool
+ operator==(const _Derived& __x, const _Derived& __y)
+ { return std::equal(__x.begin(), __x.end(), __y.begin(), __y.end()); }
+
+ template<typename _Up = value_type>
+ friend __detail::__synth3way_t<_Up>
+ operator<=>(const _Derived& __x, const _Derived& __y)
+ {
+ return std::lexicographical_compare_three_way(__x.begin(), __x.end(),
+ __y.begin(), __y.end(),
+ __detail::__synth3way);
+ }
+
+ friend void
+ swap(_Derived& __x, _Derived& __y) noexcept
+ { return __x.swap(__y); }
+
+ template<typename _Predicate>
+ friend size_type
+ erase_if(_Derived& __c, _Predicate __pred)
+ {
+ __try
+ {
+ auto __zv = views::zip(__c._M_cont.keys, __c._M_cont.values);
+ auto __sr = ranges::remove_if(__zv, __pred);
+ auto __erased = __sr.size();
+ __c.erase(__c.end() - __erased, __c.end());
+ return __erased;
+ }
+ __catch(...)
+ {
+ __c.clear();
+ __throw_exception_again;
+ }
+ }
+
+ private:
+ containers _M_cont;
+ [[no_unique_address]] _Compare _M_comp;
+
+ void
+ _M_sort_uniq()
+ {
+ auto __zv = views::zip(_M_cont.keys, _M_cont.values);
+ ranges::sort(__zv, value_comp());
+ if constexpr (!_Multi)
+ _M_unique();
+ }
+
+ void
+ _M_unique() requires (!_Multi)
+ {
+ struct __key_equiv
+ {
+ __key_equiv(key_compare __c) : _M_comp(__c) { }
+
+ bool
+ operator()(const_reference __x, const_reference __y) const
+ { return !_M_comp(__x.first, __y.first) && !_M_comp(__y.first,
__x.first); }
+
+ [[no_unique_address]] key_compare _M_comp;
+ };
+
+ auto __zv = views::zip(_M_cont.keys, _M_cont.values);
+ auto __it = ranges::unique(__zv, __key_equiv(_M_comp)).begin();
+ auto __n = __it - __zv.begin();
+ _M_cont.keys.erase(_M_cont.keys.begin() + __n, _M_cont.keys.end());
+ _M_cont.values.erase(_M_cont.values.begin() + __n,
_M_cont.values.end());
+ }
+ };
+
+ template<typename _Key, typename _Tp, typename _Compare,
+ typename _KeyContainer, typename _MappedContainer, bool _Multi>
+ template<bool _Const>
+ class _Flat_map_impl<_Key, _Tp, _Compare, _KeyContainer, _MappedContainer,
_Multi>::_Iterator
+ {
+ using __size_type = typename _Flat_map_impl::size_type;
+
+ public:
+ using iterator_category = input_iterator_tag;
+ using iterator_concept = random_access_iterator_tag;
+ using value_type = pair<const key_type, mapped_type>;
+ using reference = pair<const key_type&,
+ ranges::__maybe_const_t<_Const,
mapped_type>&>;
+ using difference_type = ptrdiff_t;
+
+ _Iterator() = default;
+
+ _Iterator(_Iterator<!_Const> __it) requires _Const
+ : _M_cont(__it._M_cont), _M_index(__it._M_index)
+ { }
+
+ reference
+ operator*() const noexcept
+ { return {_M_cont->keys[_M_index], _M_cont->values[_M_index]}; }
+
+ struct pointer
+ {
+ reference __p;
+
+ const reference*
+ operator->() const noexcept
+ { return std::__addressof(__p); }
+ };
+
+ pointer
+ operator->() const
+ { return pointer{operator*()}; }
+
+ reference
+ operator[](difference_type __n) const noexcept
+ { return *(*this + __n); }
+
+ _Iterator&
+ operator++() noexcept
+ {
+ ++_M_index;
+ return *this;
+ }
+
+ _Iterator&
+ operator--() noexcept
+ {
+ --_M_index;
+ return *this;
+ }
+
+ _Iterator
+ operator++(int) noexcept
+ {
+ auto __tmp = *this;
+ ++*this;
+ return __tmp;
+ }
+
+ _Iterator
+ operator--(int) noexcept
+ {
+ auto __tmp = *this;
+ --*this;
+ return __tmp;
+ }
+
+ _Iterator&
+ operator+=(difference_type __n) noexcept
+ {
+ _M_index += __n;
+ return *this;
+ }
+
+ _Iterator&
+ operator-=(difference_type __n) noexcept
+ {
+ _M_index -= __n;
+ return *this;
+ }
+
+ private:
+ friend _Flat_map_impl;
+ friend _Iterator<!_Const>;
+
+ _Iterator(_Flat_map_impl* __fm, typename
key_container_type::const_iterator __it)
+ requires (!_Const)
+ : _M_cont(std::__addressof(__fm->_M_cont)), _M_index(__it -
__fm->keys().cbegin())
+ { }
+
+ _Iterator(const _Flat_map_impl* __fm, typename
key_container_type::const_iterator __it)
+ requires _Const
+ : _M_cont(std::__addressof(__fm->_M_cont)), _M_index(__it -
__fm->keys().cbegin())
+ { }
+
+ friend _Iterator
+ operator+(_Iterator __it, difference_type __n) noexcept
+ {
+ __it += __n;
+ return __it;
+ }
+
+ friend _Iterator
+ operator+(difference_type __n, _Iterator __it) noexcept
+ {
+ __it += __n;
+ return __it;
+ }
+
+ friend _Iterator
+ operator-(_Iterator __it, difference_type __n) noexcept
+ {
+ __it -= __n;
+ return __it;
+ }
+
+ friend difference_type
+ operator-(const _Iterator& __x, const _Iterator& __y) noexcept
+ {
+ __glibcxx_assert(__x._M_cont == __y._M_cont);
+ return __x._M_index - __y._M_index;
+ }
+
+ friend bool
+ operator==(const _Iterator& __x, const _Iterator& __y) noexcept
+ {
+ __glibcxx_assert(__x._M_cont == __y._M_cont);
+ __glibcxx_assert((__x._M_index == size_t(-1)) == (__y._M_index ==
size_t(-1)));
+ return __x._M_index == __y._M_index;
+ }
+
+ friend strong_ordering
+ operator<=>(const _Iterator& __x, const _Iterator& __y)
+ {
+ __glibcxx_assert(__x._M_cont == __y._M_cont);
+ __glibcxx_assert((__x._M_index == size_t(-1)) == (__y._M_index ==
size_t(-1)));
+ return __x._M_index <=> __y._M_index;
+ }
+
+ ranges::__maybe_const_t<_Const, containers>* _M_cont = nullptr;
+ __size_type _M_index = -1;
+ };
+
+ /* Class template flat_map - container adaptor
+ *
+ * @ingroup
+ */
+ template<typename _Key, typename _Tp, typename _Compare = less<_Key>,
+ typename _KeyContainer = vector<_Key>,
+ typename _MappedContainer = vector<_Tp>>
+ class flat_map
+ : private _Flat_map_impl<_Key, _Tp, _Compare, _KeyContainer,
_MappedContainer, false>
+ {
+ using _Impl = _Flat_map_impl<_Key, _Tp, _Compare, _KeyContainer,
_MappedContainer, false>;
+ friend _Impl;
+
+ public:
+ // types
+ using typename _Impl::key_type;
+ using typename _Impl::mapped_type;
+ using typename _Impl::value_type;
+ using typename _Impl::key_compare;
+ using typename _Impl::reference;
+ using typename _Impl::const_reference;
+ using typename _Impl::size_type;
+ using typename _Impl::difference_type;
+ using typename _Impl::iterator;
+ using typename _Impl::const_iterator;
+ using typename _Impl::reverse_iterator;
+ using typename _Impl::const_reverse_iterator;
+ using typename _Impl::key_container_type;
+ using typename _Impl::mapped_container_type;
+ using typename _Impl::value_compare;
+ using typename _Impl::containers;
+
+ // constructors
+ using _Impl::_Impl;
+
+ // iterators
+ using _Impl::begin;
+ using _Impl::end;
+ using _Impl::rbegin;
+ using _Impl::rend;
+
+ using _Impl::cbegin;
+ using _Impl::cend;
+ using _Impl::crbegin;
+ using _Impl::crend;
+
+ // capacity
+ using _Impl::empty;
+ using _Impl::size;
+ using _Impl::max_size;
+
+ // element access
+ mapped_type&
+ operator[](const key_type& __x)
+ { return operator[]<const key_type>(__x); }
+
+ mapped_type&
+ operator[](key_type&& __x)
+ { return operator[]<key_type>(std::move(__x)); }
+
+ template<typename _Key2>
+ requires same_as<remove_cvref_t<_Key2>, _Key> ||
__transparent_comparator<_Compare>
+ mapped_type&
+ operator[](_Key2&& __x)
+ { return try_emplace(std::forward<_Key2>(__x)).first->second; }
+
+ mapped_type&
+ at(const key_type& __x)
+ { return at<key_type>(__x); }
+
+ const mapped_type&
+ at(const key_type& __x) const
+ { return at<key_type>(__x); }
+
+ template<typename _Key2>
+ requires same_as<_Key2, _Key> || __transparent_comparator<_Compare>
+ mapped_type&
+ at(const _Key2& __x)
+ {
+ auto __it = this->find(__x);
+ if (__it == this->end())
+ __throw_out_of_range("flat_map::at");
+ return __it->second;
+ }
+
+ template<typename _Key2>
+ requires same_as<_Key2, _Key> || __transparent_comparator<_Compare>
+ const mapped_type&
+ at(const _Key2& __x) const
+ {
+ auto __it = this->find(__x);
+ if (__it == this->end())
+ __throw_out_of_range("flat_map::at");
+ return __it->second;
+ }
+
+ // modifiers
+ using _Impl::emplace;
+ using _Impl::emplace_hint;
+ using _Impl::insert;
+ // using _Impl::insert_range;
+ using _Impl::extract;
+ using _Impl::replace;
+ using _Impl::erase;
+ using _Impl::swap;
+ using _Impl::clear;
+
+ template<typename... _Args>
+ requires is_constructible_v<mapped_type, _Args...>
+ pair<iterator, bool>
+ try_emplace(const key_type& __k, _Args&&... __args)
+ { return _Impl::_M_try_emplace(nullopt, __k,
std::forward<_Args>(__args)...); }
+
+ template<typename... _Args>
+ requires is_constructible_v<mapped_type, _Args...>
+ pair<iterator, bool>
+ try_emplace(key_type&& __k, _Args&&... __args)
+ {
+ return _Impl::_M_try_emplace(nullopt, std::move(__k),
+ std::forward<_Args>(__args)...);
+ }
+
+ template<typename _Key2, typename... _Args>
+ requires __transparent_comparator<_Compare>
+ && is_constructible_v<key_type, _Key2>
+ && is_constructible_v<mapped_type, _Args...>
+ && (!is_convertible_v<_Key2&&, const_iterator>)
+ && (!is_convertible_v<_Key2&&, iterator>)
+ pair<iterator, bool>
+ try_emplace(_Key2&& __k, _Args&&... __args)
+ {
+ return _Impl::_M_try_emplace(nullopt, std::forward<_Key2>(__k),
+ std::forward<_Args>(__args)...);
+ }
+
+ template<typename... _Args>
+ requires is_constructible_v<mapped_type, _Args...>
+ iterator
+ try_emplace(const_iterator __hint, const key_type& __k, _Args&&...
__args)
+ { return _Impl::_M_try_emplace(__hint, __k,
std::forward<_Args>(__args)...).first; }
+
+ template<typename... _Args>
+ requires is_constructible_v<mapped_type, _Args...>
+ iterator
+ try_emplace(const_iterator __hint, key_type&& __k, _Args&&... __args)
+ {
+ return _Impl::_M_try_emplace(__hint, std::move(__k),
+ std::forward<_Args>(__args)...).first;
+ }
+
+ template<typename _Key2, typename... _Args>
+ requires __transparent_comparator<_Compare>
+ && is_constructible_v<key_type, _Key2>
+ && is_constructible_v<mapped_type, _Args...>
+ iterator
+ try_emplace(const_iterator __hint, _Key2&& __k, _Args&&... __args)
+ {
+ return _Impl::_M_try_emplace(__hint, std::forward<_Key2>(__k),
+ std::forward<_Args>(__args)...).first;
+ }
+
+ template<typename _Mapped>
+ requires is_assignable_v<mapped_type&, _Mapped>
+ && is_constructible_v<mapped_type, _Mapped>
+ pair<iterator, bool>
+ insert_or_assign(const key_type& __k, _Mapped&& __obj)
+ { return insert_or_assign<const key_type&, _Mapped>(__k,
std::forward<_Mapped>(__obj)); }
+
+ template<typename _Mapped>
+ requires is_assignable_v<mapped_type&, _Mapped>
+ && is_constructible_v<mapped_type, _Mapped>
+ pair<iterator, bool>
+ insert_or_assign(key_type&& __k, _Mapped&& __obj)
+ {
+ return insert_or_assign<key_type, _Mapped>(std::move(__k),
+
std::forward<_Mapped>(__obj));
+ }
+
+ template<typename _Key2, typename _Mapped>
+ requires (same_as<remove_cvref_t<_Key2>, _Key> ||
__transparent_comparator<_Compare>)
+ && is_constructible_v<key_type, _Key2>
+ && is_assignable_v<mapped_type&, _Mapped>
+ && is_constructible_v<mapped_type, _Mapped>
+ pair<iterator, bool>
+ insert_or_assign(_Key2&& __k, _Mapped&& __obj)
+ {
+ auto __r = _Impl::_M_try_emplace(nullopt, std::forward<_Key2>(__k),
+ std::forward<_Mapped>(__obj));
+ if (!__r.second)
+ __r.first->second = std::forward<_Mapped>(__obj);
+ return __r;
+ }
+
+ template<typename _Mapped>
+ requires is_assignable_v<mapped_type&, _Mapped>
+ && is_constructible_v<mapped_type, _Mapped>
+ iterator
+ insert_or_assign(const_iterator __hint, const key_type& __k, _Mapped&&
__obj)
+ {
+ return insert_or_assign<const key_type&, _Mapped>(__hint, __k,
+
std::forward<_Mapped>(__obj));
+ }
+
+ template<typename _Mapped>
+ requires is_assignable_v<mapped_type&, _Mapped>
+ && is_constructible_v<mapped_type, _Mapped>
+ iterator
+ insert_or_assign(const_iterator __hint, key_type&& __k, _Mapped&& __obj)
+ {
+ return insert_or_assign<key_type, _Mapped>(__hint, std::move(__k),
+
std::forward<_Mapped>(__obj));
+ }
+
+ template<typename _Key2, typename _Mapped>
+ requires (same_as<remove_cvref_t<_Key2>, _Key> ||
__transparent_comparator<_Compare>)
+ && is_constructible_v<key_type, _Key2>
+ && is_assignable_v<mapped_type&, _Mapped>
+ && is_constructible_v<mapped_type, _Mapped>
+ iterator
+ insert_or_assign(const_iterator __hint, _Key2&& __k, _Mapped&& __obj)
+ {
+ auto __r = _Impl::_M_try_emplace(__hint, std::forward<_Key2>(__k),
+ std::forward<_Mapped>(__obj));
+ if (!__r.second)
+ __r.first->second = std::forward<_Mapped>(__obj);
+ return __r.first;
+ }
+
+ // observers
+ using _Impl::key_comp;
+ using _Impl::value_comp;
+ using _Impl::keys;
+ using _Impl::values;
+
+ // map operations
+ using _Impl::find;
+ using _Impl::count;
+ using _Impl::contains;
+ using _Impl::lower_bound;
+ using _Impl::upper_bound;
+ using _Impl::equal_range;
+ };
+
+ template<typename _KeyContainer, typename _MappedContainer,
+ typename _Compare = less<typename _KeyContainer::value_type>,
+ typename = _RequireNotAllocator<_Compare>>
+ flat_map(_KeyContainer, _MappedContainer, _Compare = _Compare())
+ -> flat_map<typename _KeyContainer::value_type, typename
_MappedContainer::value_type,
+ _Compare, _KeyContainer, _MappedContainer>;
+
+ template<typename _KeyContainer, typename _MappedContainer, typename _Alloc,
+ typename = _RequireAllocator<_Alloc>>
+ flat_map(_KeyContainer, _MappedContainer, _Alloc)
+ -> flat_map<typename _KeyContainer::value_type, typename
_MappedContainer::value_type,
+ less<typename _KeyContainer::value_type>, _KeyContainer,
_MappedContainer>;
+
+ template<typename _KeyContainer, typename _MappedContainer, typename
_Compare, typename _Alloc,
+ typename = _RequireNotAllocator<_Compare>,
+ typename = _RequireAllocator<_Alloc>>
+ flat_map(_KeyContainer, _MappedContainer, _Compare, _Alloc)
+ -> flat_map<typename _KeyContainer::value_type, typename
_MappedContainer::value_type,
+ _Compare, _KeyContainer, _MappedContainer>;
+
+ template<typename _KeyContainer, typename _MappedContainer,
+ typename _Compare = less<typename _KeyContainer::value_type>,
+ typename = _RequireNotAllocator<_Compare>>
+ flat_map(sorted_unique_t, _KeyContainer, _MappedContainer, _Compare =
_Compare())
+ -> flat_map<typename _KeyContainer::value_type, typename
_MappedContainer::value_type,
+ _Compare, _KeyContainer, _MappedContainer>;
+
+ template<typename _KeyContainer, typename _MappedContainer, typename _Alloc,
+ typename = _RequireAllocator<_Alloc>>
+ flat_map(sorted_unique_t, _KeyContainer, _MappedContainer, _Alloc)
+ -> flat_map<typename _KeyContainer::value_type, typename
_MappedContainer::value_type,
+ less<typename _KeyContainer::value_type>, _KeyContainer,
_MappedContainer>;
+
+ template<typename _KeyContainer, typename _MappedContainer, typename
_Compare, typename _Alloc,
+ typename = _RequireNotAllocator<_Compare>,
+ typename = _RequireAllocator<_Alloc>>
+ flat_map(sorted_unique_t, _KeyContainer, _MappedContainer, _Compare,
_Alloc)
+ -> flat_map<typename _KeyContainer::value_type, typename
_MappedContainer::value_type,
+ _Compare, _KeyContainer, _MappedContainer>;
+
+ template<typename _InputIterator, typename _Compare =
less<__iter_key_t<_InputIterator>>,
+ typename = _RequireInputIter<_InputIterator>,
+ typename = _RequireNotAllocator<_Compare>>
+ flat_map(_InputIterator, _InputIterator, _Compare = _Compare())
+ -> flat_map<__iter_key_t<_InputIterator>, __iter_val_t<_InputIterator>,
_Compare>;
+
+ template<typename _InputIterator, typename _Compare =
less<__iter_key_t<_InputIterator>>,
+ typename = _RequireInputIter<_InputIterator>,
+ typename = _RequireNotAllocator<_Compare>>
+ flat_map(sorted_unique_t, _InputIterator, _InputIterator, _Compare =
_Compare())
+ -> flat_map<__iter_key_t<_InputIterator>, __iter_val_t<_InputIterator>,
_Compare>;
+
+ // TODO: Implement from_range_t deduction guides.
+
+ template<typename _Key, typename _Tp, typename _Compare = less<_Key>,
+ typename = _RequireNotAllocator<_Compare>>
+ flat_map(initializer_list<pair<_Key, _Tp>>, _Compare = _Compare())
+ -> flat_map<_Key, _Tp, _Compare>;
+
+ template<typename _Key, typename _Tp, typename _Compare = less<_Key>,
+ typename = _RequireNotAllocator<_Compare>>
+ flat_map(sorted_unique_t, initializer_list<pair<_Key, _Tp>>, _Compare =
_Compare())
+ -> flat_map<_Key, _Tp, _Compare>;
+
+ template<typename _Key, typename _Tp, typename _Compare,
+ typename _KeyContainer, typename _MappedContainer, typename _Alloc>
+ struct uses_allocator<flat_map<_Key, _Tp, _Compare, _KeyContainer,
_MappedContainer>, _Alloc>
+ : bool_constant<uses_allocator_v<_KeyContainer, _Alloc>
+ && uses_allocator_v<_MappedContainer, _Alloc>>
+ { };
+
+ /* Class template flat_multimap - container adaptor
+ *
+ * @ingroup
+ */
+ template<typename _Key, typename _Tp, typename _Compare = less<_Key>,
+ typename _KeyContainer = vector<_Key>,
+ typename _MappedContainer = vector<_Tp>>
+ class flat_multimap
+ : private _Flat_map_impl<_Key, _Tp, _Compare, _KeyContainer,
_MappedContainer, true>
+ {
+ using _Impl = _Flat_map_impl<_Key, _Tp, _Compare, _KeyContainer,
_MappedContainer, true>;
+ friend _Impl;
+
+ public:
+ // types
+ using typename _Impl::key_type;
+ using typename _Impl::mapped_type;
+ using typename _Impl::value_type;
+ using typename _Impl::key_compare;
+ using typename _Impl::reference;
+ using typename _Impl::const_reference;
+ using typename _Impl::size_type;
+ using typename _Impl::difference_type;
+ using typename _Impl::iterator;
+ using typename _Impl::const_iterator;
+ using typename _Impl::reverse_iterator;
+ using typename _Impl::const_reverse_iterator;
+ using typename _Impl::key_container_type;
+ using typename _Impl::mapped_container_type;
+ using typename _Impl::value_compare;
+ using typename _Impl::containers;
+
+ // constructors
+ using _Impl::_Impl;
+
+ // iterators
+ using _Impl::begin;
+ using _Impl::end;
+ using _Impl::rbegin;
+ using _Impl::rend;
+
+ using _Impl::cbegin;
+ using _Impl::cend;
+ using _Impl::crbegin;
+ using _Impl::crend;
+
+ // capacity
+ using _Impl::empty;
+ using _Impl::size;
+ using _Impl::max_size;
+
+ // modifiers
+ using _Impl::emplace;
+ using _Impl::emplace_hint;
+ using _Impl::insert;
+ // using _Impl::insert_range;
+ using _Impl::extract;
+ using _Impl::replace;
+ using _Impl::erase;
+ using _Impl::swap;
+ using _Impl::clear;
+
+ // observers
+ using _Impl::key_comp;
+ using _Impl::value_comp;
+ using _Impl::keys;
+ using _Impl::values;
+
+ // map operations
+ using _Impl::find;
+ using _Impl::count;
+ using _Impl::contains;
+ using _Impl::lower_bound;
+ using _Impl::upper_bound;
+ using _Impl::equal_range;
+ };
+
+ template<typename _KeyContainer, typename _MappedContainer,
+ typename _Compare = less<typename _KeyContainer::value_type>,
+ typename = _RequireNotAllocator<_Compare>>
+ flat_multimap(_KeyContainer, _MappedContainer, _Compare = _Compare())
+ -> flat_multimap<typename _KeyContainer::value_type, typename
_MappedContainer::value_type,
+ _Compare, _KeyContainer, _MappedContainer>;
+
+ template<typename _KeyContainer, typename _MappedContainer, typename _Alloc,
+ typename = _RequireAllocator<_Alloc>>
+ flat_multimap(_KeyContainer, _MappedContainer, _Alloc)
+ -> flat_multimap<typename _KeyContainer::value_type, typename
_MappedContainer::value_type,
+ less<typename _KeyContainer::value_type>, _KeyContainer,
_MappedContainer>;
+
+ template<typename _KeyContainer, typename _MappedContainer, typename
_Compare, typename _Alloc,
+ typename = _RequireNotAllocator<_Compare>,
+ typename = _RequireAllocator<_Alloc>>
+ flat_multimap(_KeyContainer, _MappedContainer, _Compare, _Alloc)
+ -> flat_multimap<typename _KeyContainer::value_type, typename
_MappedContainer::value_type,
+ _Compare, _KeyContainer, _MappedContainer>;
+
+ template<typename _KeyContainer, typename _MappedContainer,
+ typename _Compare = less<typename _KeyContainer::value_type>,
+ typename = _RequireNotAllocator<_Compare>>
+ flat_multimap(sorted_equivalent_t, _KeyContainer, _MappedContainer,
_Compare = _Compare())
+ -> flat_multimap<typename _KeyContainer::value_type, typename
_MappedContainer::value_type,
+ _Compare, _KeyContainer, _MappedContainer>;
+
+ template<typename _KeyContainer, typename _MappedContainer, typename _Alloc,
+ typename = _RequireAllocator<_Alloc>>
+ flat_multimap(sorted_equivalent_t, _KeyContainer, _MappedContainer, _Alloc)
+ -> flat_multimap<typename _KeyContainer::value_type, typename
_MappedContainer::value_type,
+ less<typename _KeyContainer::value_type>, _KeyContainer,
_MappedContainer>;
+
+ template<typename _KeyContainer, typename _MappedContainer, typename
_Compare, typename _Alloc,
+ typename = _RequireNotAllocator<_Compare>,
+ typename = _RequireAllocator<_Alloc>>
+ flat_multimap(sorted_equivalent_t, _KeyContainer, _MappedContainer,
_Compare, _Alloc)
+ -> flat_multimap<typename _KeyContainer::value_type, typename
_MappedContainer::value_type,
+ _Compare, _KeyContainer, _MappedContainer>;
+
+ template<typename _InputIterator, typename _Compare =
less<__iter_key_t<_InputIterator>>,
+ typename = _RequireInputIter<_InputIterator>,
+ typename = _RequireNotAllocator<_Compare>>
+ flat_multimap(_InputIterator, _InputIterator, _Compare = _Compare())
+ -> flat_multimap<__iter_key_t<_InputIterator>,
__iter_val_t<_InputIterator>, _Compare>;
+
+ template<typename _InputIterator, typename _Compare =
less<__iter_key_t<_InputIterator>>,
+ typename = _RequireInputIter<_InputIterator>,
+ typename = _RequireNotAllocator<_Compare>>
+ flat_multimap(sorted_equivalent_t, _InputIterator, _InputIterator,
_Compare = _Compare())
+ -> flat_multimap<__iter_key_t<_InputIterator>,
__iter_val_t<_InputIterator>, _Compare>;
+
+ // TODO: Implement from_range_t deduction guides.
+
+ template<typename _Key, typename _Tp, typename _Compare = less<_Key>,
+ typename = _RequireNotAllocator<_Compare>>
+ flat_multimap(initializer_list<pair<_Key, _Tp>>, _Compare = _Compare())
+ -> flat_multimap<_Key, _Tp, _Compare>;
+
+ template<typename _Key, typename _Tp, typename _Compare = less<_Key>,
+ typename = _RequireNotAllocator<_Compare>>
+ flat_multimap(sorted_equivalent_t, initializer_list<pair<_Key, _Tp>>,
_Compare = _Compare())
+ -> flat_multimap<_Key, _Tp, _Compare>;
+
+ template<typename _Key, typename _Tp, typename _Compare,
+ typename _KeyContainer, typename _MappedContainer, typename _Alloc>
+ struct uses_allocator<flat_multimap<_Key, _Tp, _Compare, _KeyContainer,
_MappedContainer>,
+ _Alloc>
+ : bool_constant<uses_allocator_v<_KeyContainer, _Alloc>
+ && uses_allocator_v<_MappedContainer, _Alloc>>
+ { };
+
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace std
+#endif // __cpp_lib_flat_map
+#endif // _GLIBCXX_FLAT_MAP
diff --git a/libstdc++-v3/testsuite/23_containers/flat_map/1.cc
b/libstdc++-v3/testsuite/23_containers/flat_map/1.cc
new file mode 100644
index 00000000000..1e387a3ad90
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/flat_map/1.cc
@@ -0,0 +1,123 @@
+// { dg-do run { target c++23 } }
+
+#include <flat_map>
+#include <deque>
+#include <testsuite_hooks.h>
+
+#if __cpp_lib_flat_map != 202207L
+# error "Feature-test macro __cpp_lib_flat_map has wrong value in <flat_map>"
+#endif
+
+template<template<class> class Sequence>
+void
+test01()
+{
+ std::flat_map<int, int, std::less<int>, Sequence<int>, Sequence<int>> m;
+ static_assert( std::ranges::random_access_range<decltype(m)> );
+
+ m.insert({1,-1});
+ m.insert({2,-2});
+ m.insert({3,-3});
+ m.insert({1,-4});
+ m.insert({2,-5});
+ m.insert({3,-6});
+ m.insert({0, 0});
+ VERIFY( m.size() == 4 );
+ VERIFY( std::ranges::equal(m.keys(), (int[]){0, 1, 2, 3}) );
+ VERIFY( std::ranges::equal(m.values(), (int[]){0, -1, -2, -3}) );
+
+ for (int i = 0; i < 4; i++)
+ {
+ m.clear();
+ m.insert(m.end(), {0, 0});
+ m.insert(m.end(), {1,-1});
+ m.insert(m.end(), {2,-2});
+ m.insert(m.end(), {3,-3});
+ m.insert(m.begin() + i, {1,-4});
+ m.insert(m.begin() + i, {2,-5});
+ m.insert(m.begin() + i, {3,-6});
+ m.insert(m.begin() + i, {0,-7});
+ VERIFY( std::ranges::equal(m.keys(), (int[]){0, 1, 2, 3}) );
+ VERIFY( std::ranges::equal(m.values(), (int[]){0, -1, -2, -3}) );
+ }
+
+ m.clear();
+ m = {{10,0},{10,1}};
+ VERIFY( m.size() == 1 );
+ m.insert({{11,2},{12,3},{11,4}});
+ VERIFY( m.size() == 3 );
+ VERIFY( m[10] == 0 );
+ VERIFY( m[11] == 2 );
+ VERIFY( m[12] == 3 );
+ m[20] = 42;
+ VERIFY( m[20] == 42 );
+ VERIFY( m.end()[-1] == std::pair(20,42) );
+}
+
+void
+test02()
+{
+ std::flat_map<int, int, std::greater<int>> m;
+ static_assert( std::ranges::random_access_range<decltype(m)> );
+
+ auto r = m.insert({1,-1});
+ VERIFY( r.first->first == 1 && r.first->second == -1 && r.second );
+ r = m.insert({2,-2});
+ VERIFY( r.first->first == 2 && r.first->second == -2 && r.second );
+ r = m.insert({3,-3});
+ VERIFY( r.first->first == 3 && r.first->second == -3 && r.second );
+ r = m.insert({1,-4});
+ VERIFY( r.first->first == 1 && r.first->second == -1 && !r.second );
+ r = m.insert({2,-5});
+ VERIFY( r.first->first == 2 && r.first->second == -2 && !r.second );
+ r = m.insert({3,-6});
+ VERIFY( r.first->first == 3 && r.first->second == -3 && !r.second );
+ r = m.insert_or_assign(0, 0);
+ VERIFY( r.first->first == 0 && r.first->second == 0 && r.second );
+ r = m.insert_or_assign(0, 1);
+ VERIFY( r.first->first == 0 && r.first->second == 1 && !r.second );
+ VERIFY( *m.insert_or_assign(m.end(), 0, 2) == std::pair(0, 2) );
+ VERIFY( m.size() == 4 );
+ VERIFY( std::ranges::equal(m.keys(), (int[]){3, 2, 1, 0}) );
+ VERIFY( std::ranges::equal(m.values(), (int[]){-3, -2, -1, 2}) );
+
+ VERIFY( m.contains(3) && !m.contains(7) );
+ VERIFY( m.count(3) == 1 );
+}
+
+void
+test03()
+{
+ std::flat_map<int, int> m;
+ m = {std::pair(1, 2), {3, 4}, {5, 6}};
+ m.insert({std::pair(7, 8), {9, 10}});
+
+ auto it = m.find(0);
+ VERIFY( it == m.end() );
+ it = m.find(9);
+ VERIFY( it->second == 10 );
+
+ const auto n = m;
+ VERIFY( m == m );
+ VERIFY( m == n );
+
+ m.erase(m.begin());
+ m.erase(5);
+ m.erase(m.end()-2, m.end());
+ VERIFY( std::ranges::equal(m, (std::pair<int, int>[]){{3, 4}}) );
+ VERIFY( m != n );
+ VERIFY( n < m );
+
+ m = n;
+ erase_if(m, [](const auto& x) { auto [k, v] = x; return k < 5 || k > 5; });
+ VERIFY( std::ranges::equal(m, (std::pair<int, int>[]){{5, 6}}) );
+}
+
+int
+main()
+{
+ test01<std::vector>();
+ test01<std::deque>();
+ test02();
+ test03();
+}
diff --git a/libstdc++-v3/testsuite/23_containers/flat_multimap/1.cc
b/libstdc++-v3/testsuite/23_containers/flat_multimap/1.cc
new file mode 100644
index 00000000000..d9732e2afa6
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/flat_multimap/1.cc
@@ -0,0 +1,106 @@
+// { dg-do run { target c++23 } }
+
+#include <flat_map>
+#include <deque>
+#include <testsuite_hooks.h>
+
+template<template<class> class Sequence>
+void
+test01()
+{
+ std::flat_multimap<int, int, std::less<int>, Sequence<int>, Sequence<int>> m;
+ static_assert( std::ranges::random_access_range<decltype(m)> );
+
+ m.insert({1,-1});
+ m.insert({2,-2});
+ m.insert({3,-3});
+ m.insert({1,-4});
+ m.insert({2,-5});
+ m.insert({3,-6});
+ m.insert({0, 0});
+ VERIFY( m.size() == 7 );
+ VERIFY( std::ranges::equal(m.keys(), (int[]){0, 1, 1, 2, 2, 3, 3}) );
+ VERIFY( std::ranges::equal(m.values(), (int[]){0, -1, -4, -2, -5, -3, -6}) );
+
+ m.clear();
+ m.insert(m.begin(), {0, 0});
+ m.insert(m.begin(), {1,-1});
+ m.insert(m.begin(), {2,-2});
+ m.insert(m.begin(), {3,-3});
+ m.insert(m.begin(), {1,-4});
+ m.insert(m.begin(), {2,-5});
+ m.insert(m.begin(), {3,-6});
+ m.insert(m.begin(), {0,-7});
+ VERIFY( std::ranges::equal(m.keys(), (int[]){0, 0, 1, 1, 2, 2, 3, 3}) );
+ VERIFY( std::ranges::equal(m.values(), (int[]){-7, 0, -4, -1, -5, -2, -6,
-3}) );
+
+ m.clear();
+ m = {{10,0},{10,1}};
+ VERIFY( m.size() == 2 );
+ m.insert({{11,2},{12,3},{11,4}});
+ VERIFY( m.size() == 5 );
+ VERIFY( m.end()[-1] == std::pair(12,3) );
+}
+
+void
+test02()
+{
+ std::flat_multimap<int, int, std::greater<int>> m;
+ static_assert( std::ranges::random_access_range<decltype(m)> );
+
+ auto r = m.insert({1,-1});
+ VERIFY( r->first == 1 && r->second == -1 );
+ r = m.insert({2,-2});
+ VERIFY( r->first == 2 && r->second == -2 );
+ r = m.insert({3,-3});
+ VERIFY( r->first == 3 && r->second == -3 );
+ r = m.insert({1,-4});
+ VERIFY( r->first == 1 && r->second == -4 );
+ r = m.insert({2,-5});
+ VERIFY( r->first == 2 && r->second == -5 );
+ r = m.insert({3,-6});
+ VERIFY( r->first == 3 && r->second == -6 );
+ VERIFY( m.size() == 6 );
+ VERIFY( std::ranges::equal(m.keys(), (int[]){3, 3, 2, 2, 1, 1}) );
+ VERIFY( std::ranges::equal(m.values(), (int[]){-3, -6, -2, -5, -1, -4}) );
+
+ VERIFY( m.contains(3) && !m.contains(7) );
+ VERIFY( m.count(3) == 2 );
+}
+
+void
+test03()
+{
+ std::flat_multimap<int, int> m;
+ m = {std::pair(1, 2), {3, 4}, {5, 6}};
+ m.insert({std::pair(7, 8), {9, 10}});
+
+ auto it = m.find(0);
+ VERIFY( it == m.end() );
+ it = m.find(9);
+ VERIFY( it->second == 10 );
+
+ const auto n = m;
+ VERIFY( m == m );
+ VERIFY( m == n );
+
+ m.erase(m.begin());
+ m.erase(5);
+ m.erase(m.end()-2, m.end());
+ VERIFY( std::ranges::equal(m, (std::pair<int, int>[]){{3, 4}}) );
+ VERIFY( m != n );
+ VERIFY( n < m );
+
+ m = n;
+ erase_if(m, [](const auto& x) { auto [k, v] = x; return k < 5 || k > 5; });
+ VERIFY( std::ranges::equal(m, (std::pair<int, int>[]){{5, 6}}) );
+}
+
+int
+main()
+{
+ test01<std::vector>();
+ test01<std::deque>();
+ test02();
+ test03();
+}
--
2.47.0.86.g15030f9556
