[gcc r15-8291] libstdc++: Cast difference_type for insert_range unordered non-unique containers [PR119358]

[Tomasz Kaminski]

https://gcc.gnu.org/g:3b32473d3e40d816e4ba280f8a58f44957219681

commit r15-8291-g3b32473d3e40d816e4ba280f8a58f44957219681
Author: Tomasz Kamiński <tkaminsk@redhat.com>
Date:   Tue Mar 18 17:32:40 2025 +0100

    libstdc++: Cast difference_type for insert_range unordered non-unique containers [PR119358]
    
    ranges::distance may produce an integer-like class type
    (ranges::__detail::__max_diff_type) that is only explicitly convertible to
    other integer types, so the result needs to be casted to containers size_type.
    
            PR libstdc++/119358
    
    libstdc++-v3/ChangeLog:
    
            * include/bits/unordered_map.h (unordered_multimap::insert_range):
            Cast ranges::distance to size_type before passing to _M_rehash_insert.
            * include/bits/unordered_set.h (unordered_multiset::insert_range):
            Same as unordered_multimap::insert_range.
            * testsuite/23_containers/unordered_multimap/cons/from_range.cc:
            New tests.
            * testsuite/23_containers/unordered_multiset/cons/from_range.cc:
            New tests.

Diff:
---
 libstdc++-v3/include/bits/unordered_map.h                    |  2 +-
 libstdc++-v3/include/bits/unordered_set.h                    |  2 +-
 .../23_containers/unordered_multimap/cons/from_range.cc      | 12 ++++++++++++
 .../23_containers/unordered_multiset/cons/from_range.cc      | 11 +++++++++++
 4 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/libstdc++-v3/include/bits/unordered_map.h b/libstdc++-v3/include/bits/unordered_map.h
index 5c9304871907..4a0527c6025e 100644
--- a/libstdc++-v3/include/bits/unordered_map.h
+++ b/libstdc++-v3/include/bits/unordered_map.h
@@ -1805,7 +1805,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
 	    return;
 
 	  if constexpr (ranges::forward_range<_Rg> || ranges::sized_range<_Rg>)
-	    _M_h._M_rehash_insert(ranges::distance(__rg));
+	    _M_h._M_rehash_insert(size_type(ranges::distance(__rg)));
 	  else
 	    _M_h._M_rehash_insert(1);
 
diff --git a/libstdc++-v3/include/bits/unordered_set.h b/libstdc++-v3/include/bits/unordered_set.h
index 21ffdaf50a02..cfa8ee297f4e 100644
--- a/libstdc++-v3/include/bits/unordered_set.h
+++ b/libstdc++-v3/include/bits/unordered_set.h
@@ -1485,7 +1485,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
 	    return;
 
 	  if constexpr (ranges::forward_range<_Rg> || ranges::sized_range<_Rg>)
-	    _M_h._M_rehash_insert(ranges::distance(__rg));
+	    _M_h._M_rehash_insert(size_type(ranges::distance(__rg)));
 	  else
 	    _M_h._M_rehash_insert(1);
 
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
index 9273ef0d57a3..381302bf7fd4 100644
--- a/libstdc++-v3/testsuite/23_containers/unordered_multimap/cons/from_range.cc
+++ b/libstdc++-v3/testsuite/23_containers/unordered_multimap/cons/from_range.cc
@@ -2,6 +2,7 @@
 
 #include <algorithm>
 #include <unordered_map>
+#include <ranges>
 #include <span>
 #include <testsuite_allocator.h>
 #include <testsuite_hooks.h>
@@ -232,7 +233,18 @@ test_ranges()
   return true;
 }
 
+void test_PR119358() {
+#ifdef __SIZEOF_INT128__
+  auto r = std::views::iota(__int128(0))
+	 | std::views::take(5);
+  auto z = std::views::zip(r, r);
+  std::unordered_multimap<__int128, __int128> m(std::from_range, z);
+  VERIFY( std::ranges::is_permutation(m, z) );
+#endif
+}
+
 int main()
 {
   test_ranges();
+  test_PR119358();
 }
diff --git a/libstdc++-v3/testsuite/23_containers/unordered_multiset/cons/from_range.cc b/libstdc++-v3/testsuite/23_containers/unordered_multiset/cons/from_range.cc
index fb3887644233..cb522b012aae 100644
--- a/libstdc++-v3/testsuite/23_containers/unordered_multiset/cons/from_range.cc
+++ b/libstdc++-v3/testsuite/23_containers/unordered_multiset/cons/from_range.cc
@@ -2,6 +2,7 @@
 
 #include <algorithm>
 #include <unordered_set>
+#include <ranges>
 #include <span>
 #include <testsuite_allocator.h>
 #include <testsuite_hooks.h>
@@ -195,7 +196,17 @@ test_ranges()
   return true;
 }
 
+void test_PR119358() {
+#ifdef __SIZEOF_INT128__
+  auto r = std::views::iota(__int128(0))
+	 | std::views::take(5);
+  std::unordered_multiset<__int128> s(std::from_range, r);
+  VERIFY( std::ranges::is_permutation(s, r) );
+#endif
+}
+
 int main()
 {
   test_ranges();
+  test_PR119358();
 }