+ template<__detail::__container_compatible_range<value_type> _Rg>
+ unordered_multimap(from_range_t, _Rg&& __rg,
+ size_type __n = 0,
+ const hasher& __hf = hasher(),
+ const key_equal& __eql = key_equal(),
+ const allocator_type& __a = allocator_type())
+ : _M_h(__n, __hf, __eql, __a)
+ { insert_range(std::forward<_Rg>(__rg)); }
+
+ template<__detail::__container_compatible_range<value_type> _Rg>
+ unordered_multimap(from_range_t, _Rg&& __rg, size_type __n,
+ const allocator_type& __a)
+ : _M_h(__n, hasher(), key_equal(), __a)
+ { insert_range(std::forward<_Rg>(__rg)); }
+
+ template<__detail::__container_compatible_range<value_type> _Rg>
+ unordered_multimap(from_range_t, _Rg&& __rg, size_type __n,
+ const hasher& __hf, const allocator_type& __a)
+ : _M_h(__n, __hf, key_equal(), __a)
+ { insert_range(std::forward<_Rg>(__rg)); }
+#endif
+
/// Copy assignment operator.
unordered_multimap&
operator=(const unordered_multimap&) = default;
@@ -1655,6 +1791,32 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
insert(initializer_list<value_type> __l)
{ _M_h.insert(__l); }
+#if __glibcxx_ranges_to_container // C++ >= 23
+ /**
+ * @brief Inserts a range of elements.
+ * @since C++23
+ * @param __rg An input range of elements that can be converted to
+ * the maps's value type.
+ */
+ template<__detail::__container_compatible_range<value_type> _Rg>
+ void
+ insert_range(_Rg&& __rg)
+ {
+ auto __first = ranges::begin(__rg);
+ const auto __last = ranges::end(__rg);
+ if (__first == __last)
+ return;
+
+ if constexpr (ranges::forward_range<_Rg> || ranges::sized_range<_Rg>)
+ _M_h._M_rehash_insert(ranges::distance(__rg));
+ else
+ _M_h._M_rehash_insert(1);
+
+ for (; __first != __last; ++__first)
+ _M_h.emplace(*__first);
+ }
+#endif
+
#ifdef __glibcxx_node_extract // >= C++17 && HOSTED
/// Extract a node.
node_type
@@ -2138,6 +2300,50 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
_Hash, _Allocator)
-> unordered_multimap<_Key, _Tp, _Hash, equal_to<_Key>, _Allocator>;
+#if __glibcxx_ranges_to_container // C++ >= 23
+ template<ranges::input_range _Rg,
+ __not_allocator_like _Hash = hash<__detail::__range_key_type<_Rg>>,
+ __not_allocator_like _Pred =
equal_to<__detail::__range_key_type<_Rg>>,
+ __allocator_like _Allocator =
+ allocator<__detail::__range_to_alloc_type<_Rg>>>
+ unordered_multimap(from_range_t, _Rg&&,
+ unordered_multimap<int, int>::size_type = {},
+ _Hash = _Hash(), _Pred = _Pred(),
+ _Allocator = _Allocator())
+ -> unordered_multimap<__detail::__range_key_type<_Rg>,
+ __detail::__range_mapped_type<_Rg>,
+ _Hash, _Pred, _Allocator>;
+
+ template<ranges::input_range _Rg,
+ __allocator_like _Allocator>
+ unordered_multimap(from_range_t, _Rg&&, unordered_multimap<int,
int>::size_type,
+ _Allocator)
+ -> unordered_multimap<__detail::__range_key_type<_Rg>,
+ __detail::__range_mapped_type<_Rg>,
+ hash<__detail::__range_key_type<_Rg>>,
+ equal_to<__detail::__range_key_type<_Rg>>,
+ _Allocator>;
+
+ template<ranges::input_range _Rg,
+ __allocator_like _Allocator>
+ unordered_multimap(from_range_t, _Rg&&, _Allocator)
+ -> unordered_multimap<__detail::__range_key_type<_Rg>,
+ __detail::__range_mapped_type<_Rg>,
+ hash<__detail::__range_key_type<_Rg>>,
+ equal_to<__detail::__range_key_type<_Rg>>,
+ _Allocator>;
+
+ template<ranges::input_range _Rg,
+ __not_allocator_like _Hash,
+ __allocator_like _Allocator>
+ unordered_multimap(from_range_t, _Rg&&,
+ unordered_multimap<int, int>::size_type,
+ _Hash, _Allocator)
+ -> unordered_multimap<__detail::__range_key_type<_Rg>,
+ __detail::__range_mapped_type<_Rg>,
+ _Hash, equal_to<__detail::__range_key_type<_Rg>>,
+ _Allocator>;
+#endif
#endif
template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
diff --git
a/libstdc++-v3/testsuite/23_containers/unordered_map/cons/from_range.cc
b/libstdc++-v3/testsuite/23_containers/unordered_map/cons/from_range.cc
new file mode 100644
index 00000000000..b3cbb2e6062
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/unordered_map/cons/from_range.cc
@@ -0,0 +1,232 @@
+// { dg-do run { target c++23 } }
+
+#include <algorithm>
+#include <unordered_map>
+#include <span>
+#include <testsuite_allocator.h>
+#include <testsuite_hooks.h>
+#include <testsuite_iterators.h>
+
+struct StateHash {
+ int state = 17;
+
+ template<typename T>
+ size_t operator()(T const& t) const {
+ return std::hash<T>()(t) + 43;
+ }
+};
+
+struct StateEq {
+ int state = 7;
+
+ template<typename T, typename U>
+ bool operator()(T const& l, U const & r) const {
+ return l == r;
+ }
+};
+
+void
+test_deduction_guide()
+{
+ __gnu_test::test_input_range<std::pair<long, float>> r(0, 0);
+ std::unordered_map m(std::from_range, r);
+ static_assert(std::is_same_v<decltype(m), std::unordered_map<long, float>>);
+
+ std::unordered_map m2(std::from_range, r, 0);
+ static_assert(std::is_same_v<decltype(m2), std::unordered_map<long, float>>);
+
+ StateHash hf;
+ std::unordered_map m3(std::from_range, r, 0, hf);
+ static_assert(std::is_same_v<
+ decltype(m3),
+ std::unordered_map<long, float, StateHash>>);
+
+ StateEq eq;
+ std::unordered_map m4(std::from_range, r, 0, hf, eq);
+ static_assert(std::is_same_v<
+ decltype(m4),
+ std::unordered_map<long, float, StateHash, StateEq>>);
+
+ using Alloc = __gnu_test::SimpleAllocator<std::pair<const long, float>>;
+ Alloc alloc;
+ // LWG2713: there is no matching constructor
+ // std::unordered_map m5(std::from_range, r, alloc);
+ // static_assert(std::is_same_v<
+ // decltype(m5),
+ // std::unordered_map<long, float,
+ // std::hash<long>, std::equal_to<long>, Alloc>>);
+
+ std::unordered_map m6(std::from_range, r, 0, alloc);
+ static_assert(std::is_same_v<
+ decltype(m6),
+ std::unordered_map<long, float,
+ std::hash<long>, std::equal_to<long>, Alloc>>);
+
+ std::unordered_map m7(std::from_range, r, 0, hf, alloc);
+ static_assert(std::is_same_v<
+ decltype(m7),
+ std::unordered_map<long, float, StateHash, std::equal_to<long>, Alloc>>);
+
+ std::unordered_map m8(std::from_range, r, 0, hf, eq, alloc);
+ static_assert(std::is_same_v<
+ decltype(m8),
+ std::unordered_map<long, float, StateHash, StateEq, Alloc>>);
+
+ __gnu_test::test_input_range<std::pair<const long, const float>> r2(0, 0);
+ std::unordered_map m9(std::from_range, r2);
+ static_assert(std::is_same_v<
+ decltype(m9),
+ std::unordered_map<long, const float>>);
+
+ // LWG4223: deduces map<const long&, float&>
+ // __gnu_test::test_input_range<std::pair<const long&, float&>> r3(0, 0);
+ // std::unordered_map m10(std::from_range, r3);
+
+ // LWG4223: no deduction guide
+ // __gnu_test::test_input_range<std::tuple<long, float>> r4(0, 0);
+ // std::unordered_map m11(std::from_range, r4);
+}
+
+template<typename T, typename U>
+constexpr bool is_equal(std::hash<T>, std::hash<U>)
+{ return true; }
+
+template<typename T, typename U>
+constexpr bool is_equal(std::equal_to<T>, std::equal_to<U>)
+{ return true; }
+
+constexpr bool is_equal(StateHash lhs, StateHash rhs)
+{ return lhs.state = rhs.state; }
+
+constexpr bool is_equal(StateEq lhs, StateEq rhs)
+{ return lhs.state = rhs.state; }
+
+template<typename Range, typename Alloc, typename Hash, typename Equal>
+constexpr void
+do_test(Alloc alloc, Hash hf, Equal eqf)
+{
+ // The map's value_type, key_type and mapped_type.
+ using P = typename Alloc::value_type;
+ using K = typename P::first_type;
+ using V = typename P::second_type;
+
+ // The range's value_type.
+ using T = std::ranges::range_value_t<Range>;
+ T a[]{{1,2},{2,3},{3,4},{4,5},{5,6},{6,7},{7,8},{8,9},{9,0},
+ {1,1},{2,2},{3,3},{4,4},{5,5}};
+
+ auto eq = [&](std::unordered_map<K, V, Hash, Equal, Alloc> const& l,
+ std::span<T> r) {
+ if (l.size() != r.size())
+ return false;
+
+ return std::ranges::is_permutation(l, r);
+ };
+
+ std::unordered_map<K, V, Hash, Equal, Alloc>
+ m0(std::from_range, Range(a, a+0));
+ VERIFY( m0.empty() );
+ VERIFY( is_equal(m0.hash_function(), Hash()) );
+ VERIFY( is_equal(m0.key_eq(), Equal()) );
+ VERIFY( m0.get_allocator() == Alloc() );
+
+ std::unordered_map<K, V, Hash, Equal, Alloc>
+ m4(std::from_range, Range(a, a+4), 2);
+ VERIFY( eq(m4, {a, 4}) );
+ VERIFY( m4.bucket_count() >= 2 );
+ VERIFY( is_equal(m4.hash_function(), Hash()) );
+ VERIFY( is_equal(m4.key_eq(), Equal()) );
+ VERIFY( m4.get_allocator() == Alloc() );
+
+ std::unordered_map<K, V, Hash, Equal, Alloc>
+ m7(std::from_range, Range(a, a+7), 3, hf);
+ VERIFY( eq(m7, {a, 7}) );
+ VERIFY( m7.bucket_count() >= 3 );
+ VERIFY( is_equal(m7.hash_function(), hf) );
+ VERIFY( is_equal(m7.key_eq(), Equal()) );
+ VERIFY( m7.get_allocator() == Alloc() );
+
+ std::unordered_map<K, V, Hash, Equal, Alloc>
+ m9(std::from_range, Range(a, a+9), 5, hf, eqf);
+ VERIFY( eq(m9, {a, 9}) );
+ VERIFY( m9.bucket_count() >= 5 );
+ VERIFY( m9.get_allocator() == Alloc() );
+ VERIFY( is_equal(m9.hash_function(), hf) );
+ VERIFY( is_equal(m9.key_eq(), eqf) );
+
+ // LWG2713: there is no matching constructor
+ // std::unordered_map<K, V, Hash, Equal, Alloc>
+ // ma1(std::from_range, Range(a, a+14), alloc);
+ // VERIFY( eq(ma1, {a, 9}) );
+ // VERIFY( is_equal(ma1.hash_function(), Hash()) );
+ // VERIFY( is_equal(ma1.key_eq(), Equal()) );
+ // VERIFY( ma1.get_allocator() == alloc );
+
+ std::unordered_map<K, V, Hash, Equal, Alloc>
+ ma2(std::from_range, Range(a, a+14), 2, alloc);
+ VERIFY( eq(ma2, {a, 9}) );
+ VERIFY( ma2.bucket_count() >= 2 );
+ VERIFY( is_equal(ma2.hash_function(), Hash()) );
+ VERIFY( is_equal(ma2.key_eq(), Equal()) );
+ VERIFY( ma2.get_allocator() == alloc );
+
+ std::unordered_map<K, V, Hash, Equal, Alloc>
+ ma3(std::from_range, Range(a, a+14), 3, hf, alloc);
+ VERIFY( eq(ma3, {a, 9}) );
+ VERIFY( ma3.bucket_count() >= 3 );
+ VERIFY( is_equal(ma3.hash_function(), hf) );
+ VERIFY( is_equal(ma3.key_eq(), Equal()) );
+ VERIFY( ma3.get_allocator() == alloc );
+
+ std::unordered_map<K, V, Hash, Equal, Alloc>
+ ma4(std::from_range, Range(a, a+14), 5, hf, eqf, alloc);
+ VERIFY( eq(ma4, {a, 9}) );
+ VERIFY( ma4.bucket_count() >= 5 );
+ VERIFY( is_equal(ma4.hash_function(), hf) );
+ VERIFY( is_equal(ma4.key_eq(), eqf) );
+ VERIFY( ma4.get_allocator() == alloc );
+}
+
+template<typename Range>
+void
+do_test_ahe()
+{
+ do_test<Range>(std::allocator<std::pair<const int, double>>(),
+ std::hash<int>(), std::equal_to<int>());
+ do_test<Range>(std::allocator<std::pair<const int, double>>(),
+ StateHash{27}, StateEq{17});
+ do_test<Range>(__gnu_test::uneq_allocator<std::pair<const int, double>>(42),
+ std::hash<int>(), std::equal_to<int>());
+ do_test<Range>(__gnu_test::uneq_allocator<std::pair<const int, double>>(42),
+ StateHash{27}, StateEq{17});
+}
+
+struct MyPair {
+ long x;
+ long y;
+
+ constexpr operator std::pair<int const, double>() const
+ { return {x, y}; }
+
+ friend bool operator==(MyPair, MyPair) = default;
+ constexpr friend bool operator==(MyPair lhs, std::pair<int const, double>
rhs)
+ { return (lhs.x == rhs.first) && (lhs.y == rhs.second); }
+};
+
+bool
+test_ranges()
+{
+ using namespace __gnu_test;
+
+ do_test_ahe<test_forward_range<std::pair<int, double>>>();
+ do_test_ahe<test_forward_range<std::pair<short, float>>>();
+ do_test_ahe<test_forward_range<std::tuple<int, double>>>();
+ do_test_ahe<test_forward_range<MyPair>>();
+
+ return true;
+}
+
+int main()
+{
+ test_ranges();
+}
diff --git
a/libstdc++-v3/testsuite/23_containers/unordered_map/modifiers/insert_range.cc
b/libstdc++-v3/testsuite/23_containers/unordered_map/modifiers/insert_range.cc
new file mode 100644
index 00000000000..41be2fdc196
--- /dev/null
+++
b/libstdc++-v3/testsuite/23_containers/unordered_map/modifiers/insert_range.cc
@@ -0,0 +1,79 @@
+// { dg-do run { target c++23 } }
+
+#include <algorithm>
+#include <unordered_map>
+#include <span>
+#include <testsuite_allocator.h>
+#include <testsuite_hooks.h>
+#include <testsuite_iterators.h>
+
+template<typename Range, typename K, typename V>
+constexpr void
+do_test()
+{
+ // The range's value_type.
+ using T = std::ranges::range_value_t<Range>;
+ T a[]{{1,2},{2,3},{3,4},{4,5},{5,6},{6,7},{7,8},{8,9},{9,0},
+ {1,1},{2,2},{3,3},{4,4},{5,5}};
+
+ auto eq = [&](std::unordered_map<K, V> const& l,
+ std::span<T> r) {
+ if (l.size() != r.size())
+ return false;
+
+ return std::ranges::is_permutation(l, r);
+ };
+
+ std::unordered_map<K, V> m;
+ m.insert_range(Range(a, a+0));
+ VERIFY( m.empty() );
+
+ m.insert_range(Range(a, a+4));
+ VERIFY( eq(m, {a, 4}) );
+
+ m.insert_range(Range(a+4, a+7));
+ VERIFY( eq(m, {a, 7}) );
+
+ m.insert_range(Range(a, a+9));
+ VERIFY( eq(m, {a, 9}) );
+
+ m.insert_range(Range(a, a+14));
+ VERIFY( eq(m, {a, 9}) );
+}
+
+struct MyPair {
+ long x;
+ long y;
+
+ constexpr operator std::pair<int const, double>() const
+ { return {x, y}; }
+
+ friend bool operator==(MyPair, MyPair) = default;
+ constexpr friend bool operator==(MyPair lhs, std::pair<int const, double>
rhs)
+ { return (lhs.x == rhs.first) && (lhs.y == rhs.second); }
+};
+
+template<typename Range>
+void
+do_test_v()
+{
+ do_test<Range, int, double>();
+}
+
+bool
+test_ranges()
+{
+ using namespace __gnu_test;
+
+ do_test_v<test_forward_range<std::pair<int, double>>>();
+ do_test_v<test_forward_range<std::pair<short, float>>>();
+ do_test_v<test_forward_range<std::tuple<int, double>>>();
+ do_test_v<test_forward_range<MyPair>>();
+
+ return true;
+}
+
+int main()
+{
+ test_ranges();
+}
diff --git
a/libstdc++-v3/testsuite/23_containers/unordered_multimap/cons/from_range.cc
b/libstdc++-v3/testsuite/23_containers/unordered_multimap/cons/from_range.cc
new file mode 100644
index 00000000000..9273ef0d57a
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/unordered_multimap/cons/from_range.cc
@@ -0,0 +1,238 @@
+// { dg-do run { target c++23 } }
+
+#include <algorithm>
+#include <unordered_map>
+#include <span>
+#include <testsuite_allocator.h>
+#include <testsuite_hooks.h>
+#include <testsuite_iterators.h>
+
+struct StateHash {
+ int state = 17;
+
+ template<typename T>
+ size_t operator()(T const& t) const {
+ return std::hash<T>()(t) + 43;
+ }
+};
+
+struct StateEq {
+ int state = 7;
+
+ template<typename T, typename U>
+ bool operator()(T const& l, U const & r) const {
+ return l == r;
+ }
+};
+
+void
+test_deduction_guide()
+{
+ __gnu_test::test_input_range<std::pair<long, float>> r(0, 0);
+ std::unordered_multimap m(std::from_range, r);
+ static_assert(std::is_same_v<
+ decltype(m),
+ std::unordered_multimap<long, float>>);
+
+ std::unordered_multimap m2(std::from_range, r, 0);
+ static_assert(std::is_same_v<
+ decltype(m2),
+ std::unordered_multimap<long, float>>);
+
+ StateHash hf;
+ std::unordered_multimap m3(std::from_range, r, 0, hf);
+ static_assert(std::is_same_v<
+ decltype(m3),
+ std::unordered_multimap<long, float, StateHash>>);
+
+ StateEq eq;
+ std::unordered_multimap m4(std::from_range, r, 0, hf, eq);
+ static_assert(std::is_same_v<
+ decltype(m4),
+ std::unordered_multimap<long, float, StateHash, StateEq>>);
+
+ using Alloc = __gnu_test::SimpleAllocator<std::pair<const long, float>>;
+ Alloc alloc;
+ // LWG2713: there is no matching constructor
+ // std::unordered_multimap m5(std::from_range, r, alloc);
+ // static_assert(std::is_same_v<
+ // decltype(m5),
+ // std::unordered_multimap<long, float,
+ // std::hash<long>, std::equal_to<long>, Alloc>>);
+
+ std::unordered_multimap m6(std::from_range, r, 0, alloc);
+ static_assert(std::is_same_v<
+ decltype(m6),
+ std::unordered_multimap<long, float,
+ std::hash<long>, std::equal_to<long>, Alloc>>);
+
+ std::unordered_multimap m7(std::from_range, r, 0, hf, alloc);
+ static_assert(std::is_same_v<
+ decltype(m7),
+ std::unordered_multimap<long, float,
+ StateHash, std::equal_to<long>, Alloc>>);
+
+ std::unordered_multimap m8(std::from_range, r, 0, hf, eq, alloc);
+ static_assert(std::is_same_v<
+ decltype(m8),
+ std::unordered_multimap<long, float, StateHash, StateEq, Alloc>>);
+
+ __gnu_test::test_input_range<std::pair<const long, const float>> r2(0, 0);
+ std::unordered_multimap m9(std::from_range, r2);
+ static_assert(std::is_same_v<
+ decltype(m9),
+ std::unordered_multimap<long, const float>>);
+
+ // LWG4223: deduces map<const long&, float&>
+ // __gnu_test::test_input_range<std::pair<const long&, float&>> r3(0, 0);
+ // std::unordered_multimap m10(std::from_range, r3);
+
+ // LWG4223: no deduction guide
+ // __gnu_test::test_input_range<std::tuple<long, float>> r4(0, 0);
+ // std::unordered_multimap m11(std::from_range, r4);
+}
+
+template<typename T, typename U>
+constexpr bool is_equal(std::hash<T>, std::hash<U>)
+{ return true; }
+
+template<typename T, typename U>
+constexpr bool is_equal(std::equal_to<T>, std::equal_to<U>)
+{ return true; }
+
+constexpr bool is_equal(StateHash lhs, StateHash rhs)
+{ return lhs.state = rhs.state; }
+
+constexpr bool is_equal(StateEq lhs, StateEq rhs)
+{ return lhs.state = rhs.state; }
+
+template<typename Range, typename Alloc, typename Hash, typename Equal>
+constexpr void
+do_test(Alloc alloc, Hash hf, Equal eqf)
+{
+ // The map's value_type, key_type and mapped_type.
+ using P = typename Alloc::value_type;
+ using K = typename P::first_type;
+ using V = typename P::second_type;
+
+ // The range's value_type.
+ using T = std::ranges::range_value_t<Range>;
+ T a[]{{1,2},{2,3},{3,4},{4,5},{5,6},{6,7},{7,8},{8,9},{9,0},
+ {1,1},{2,2},{3,3},{4,4},{5,5}};
+
+ auto eq = [&](std::unordered_multimap<K, V, Hash, Equal, Alloc> const& l,
+ std::span<T> r) {
+ if (l.size() != r.size())
+ return false;
+
+ return std::ranges::is_permutation(l, r);
+ };
+
+ std::unordered_multimap<K, V, Hash, Equal, Alloc>
+ m0(std::from_range, Range(a, a+0));
+ VERIFY( m0.empty() );
+ VERIFY( is_equal(m0.hash_function(), Hash()) );
+ VERIFY( is_equal(m0.key_eq(), Equal()) );
+ VERIFY( m0.get_allocator() == Alloc() );
+
+ std::unordered_multimap<K, V, Hash, Equal, Alloc>
+ m4(std::from_range, Range(a, a+4), 2);
+ VERIFY( eq(m4, {a, 4}) );
+ VERIFY( m4.bucket_count() >= 2 );
+ VERIFY( is_equal(m4.hash_function(), Hash()) );
+ VERIFY( is_equal(m4.key_eq(), Equal()) );
+ VERIFY( m4.get_allocator() == Alloc() );
+
+ std::unordered_multimap<K, V, Hash, Equal, Alloc>
+ m7(std::from_range, Range(a, a+7), 3, hf);
+ VERIFY( eq(m7, {a, 7}) );
+ VERIFY( m7.bucket_count() >= 3 );
+ VERIFY( is_equal(m7.hash_function(), hf) );
+ VERIFY( is_equal(m7.key_eq(), Equal()) );
+ VERIFY( m7.get_allocator() == Alloc() );
+
+ std::unordered_multimap<K, V, Hash, Equal, Alloc>
+ m9(std::from_range, Range(a, a+9), 5, hf, eqf);
+ VERIFY( eq(m9, {a, 9}) );
+ VERIFY( m9.bucket_count() >= 5 );
+ VERIFY( m9.get_allocator() == Alloc() );
+ VERIFY( is_equal(m9.hash_function(), hf) );
+ VERIFY( is_equal(m9.key_eq(), eqf) );
+
+ // LWG2713: there is no matching constructor
+ // std::unordered_multimap<K, V, Hash, Equal, Alloc>
+ // ma1(std::from_range, Range(a, a+14), alloc);
+ // VERIFY( eq(ma1, {a, 14}) );
+ // VERIFY( is_equal(ma1.hash_function(), Hash()) );
+ // VERIFY( is_equal(ma1.key_eq(), Equal()) );
+ // VERIFY( ma1.get_allocator() == alloc );
+
+ std::unordered_multimap<K, V, Hash, Equal, Alloc>
+ ma2(std::from_range, Range(a, a+14), 2, alloc);
+ VERIFY( eq(ma2, {a, 14}) );
+ VERIFY( ma2.bucket_count() >= 2 );
+ VERIFY( is_equal(ma2.hash_function(), Hash()) );
+ VERIFY( is_equal(ma2.key_eq(), Equal()) );
+ VERIFY( ma2.get_allocator() == alloc );
+
+ std::unordered_multimap<K, V, Hash, Equal, Alloc>
+ ma3(std::from_range, Range(a, a+14), 3, hf, alloc);
+ VERIFY( eq(ma3, {a, 14}) );
+ VERIFY( ma3.bucket_count() >= 3 );
+ VERIFY( is_equal(ma3.hash_function(), hf) );
+ VERIFY( is_equal(ma3.key_eq(), Equal()) );
+ VERIFY( ma3.get_allocator() == alloc );
+
+ std::unordered_multimap<K, V, Hash, Equal, Alloc>
+ ma4(std::from_range, Range(a, a+14), 5, hf, eqf, alloc);
+ VERIFY( eq(ma4, {a, 14}) );
+ VERIFY( ma4.bucket_count() >= 5 );
+ VERIFY( is_equal(ma4.hash_function(), hf) );
+ VERIFY( is_equal(ma4.key_eq(), eqf) );
+ VERIFY( ma4.get_allocator() == alloc );
+}
+
+template<typename Range>
+void
+do_test_ahe()
+{
+ do_test<Range>(std::allocator<std::pair<const int, double>>(),
+ std::hash<int>(), std::equal_to<int>());
+ do_test<Range>(std::allocator<std::pair<const int, double>>(),
+ StateHash{27}, StateEq{17});
+ do_test<Range>(__gnu_test::uneq_allocator<std::pair<const int, double>>(42),
+ std::hash<int>(), std::equal_to<int>());
+ do_test<Range>(__gnu_test::uneq_allocator<std::pair<const int, double>>(42),
+ StateHash{27}, StateEq{17});
+}
+
+struct MyPair {
+ long x;
+ long y;
+
+ constexpr operator std::pair<int const, double>() const
+ { return {x, y}; }
+
+ friend bool operator==(MyPair, MyPair) = default;
+ constexpr friend bool operator==(MyPair lhs, std::pair<int const, double>
rhs)
+ { return (lhs.x == rhs.first) && (lhs.y == rhs.second); }
+};
+
+bool
+test_ranges()
+{
+ using namespace __gnu_test;
+
+ do_test_ahe<test_forward_range<std::pair<int, double>>>();
+ do_test_ahe<test_range_nocopy<std::pair<int, double>,
input_iterator_wrapper_nocopy>>();
+ do_test_ahe<test_forward_range<std::pair<short, float>>>();
+ do_test_ahe<test_forward_range<std::tuple<int, double>>>();
+ do_test_ahe<test_forward_range<MyPair>>();
+
+ return true;
+}
+
+int main()
+{
+ test_ranges();
+}
diff --git
a/libstdc++-v3/testsuite/23_containers/unordered_multimap/modifiers/insert_range.cc
b/libstdc++-v3/testsuite/23_containers/unordered_multimap/modifiers/insert_range.cc
new file mode 100644
index 00000000000..30503e51fd7
--- /dev/null
+++
b/libstdc++-v3/testsuite/23_containers/unordered_multimap/modifiers/insert_range.cc
@@ -0,0 +1,76 @@
+// { dg-do run { target c++23 } }
+
+#include <algorithm>
+#include <unordered_map>
+#include <span>
+#include <testsuite_allocator.h>
+#include <testsuite_hooks.h>
+#include <testsuite_iterators.h>
+
+template<typename Range, typename K, typename V>
+constexpr void
+do_test()
+{
+ // The range's value_type.
+ using T = std::ranges::range_value_t<Range>;
+ T a[]{{1,2},{2,3},{3,4},{4,5},{5,6},{6,7},{7,8},{8,9},{9,0},
+ {1,1},{2,2},{3,3},{4,4},{5,5}};
+
+ auto eq = [&](std::unordered_multimap<K, V> const& l,
+ std::span<T> r) {
+ if (l.size() != r.size())
+ return false;
+
+ return std::ranges::is_permutation(l, r);
+ };
+
+ std::unordered_multimap<K, V> m;
+ m.insert_range(Range(a, a+0));
+ VERIFY( m.empty() );
+
+ m.insert_range(Range(a, a+4));
+ VERIFY( eq(m, {a, 4}) );
+
+ m.insert_range(Range(a+4, a+9));
+ VERIFY( eq(m, {a, 9}) );
+
+ m.insert_range(Range(a+9, a+14));
+ VERIFY( eq(m, {a, 14}) );
+}
+
+struct MyPair {
+ long x;
+ long y;
+
+ constexpr operator std::pair<int const, double>() const
+ { return {x, y}; }
+
+ friend bool operator==(MyPair, MyPair) = default;
+ constexpr friend bool operator==(MyPair lhs, std::pair<int const, double>
rhs)
+ { return (lhs.x == rhs.first) && (lhs.y == rhs.second); }
+};
+
+template<typename Range>
+void
+do_test_v()
+{
+ do_test<Range, int, double>();
+}
+
+bool
+test_ranges()
+{
+ using namespace __gnu_test;
+
+ do_test_v<test_forward_range<std::pair<int, double>>>();
+ do_test_v<test_forward_range<std::pair<short, float>>>();
+ do_test_v<test_forward_range<std::tuple<int, double>>>();
+ do_test_v<test_forward_range<MyPair>>();
+
+ return true;
+}
+
+int main()
+{
+ test_ranges();
+}
--
2.48.1
