commit 6ccffeb56b92041991aba923545532087e1977f5
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Thu May 13 14:30:26 2021

    libstdc++: Implement LWG 3506 for std::priority_queue
    
    The LWG 3506 issue ads allocator-extended versions of the constructors
    that take iterator arguments.
    
    Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
    
    libstdc++-v3/ChangeLog:
    
            * include/bits/stl_queue.h (priority_queue): Add
            allocator-extended overloads for constructors taking iterator.
            * testsuite/23_containers/priority_queue/lwg3506.cc: New test.

diff --git a/libstdc++-v3/include/bits/stl_queue.h b/libstdc++-v3/include/bits/stl_queue.h
index f801ebda77f..4519f9f2fec 100644
--- a/libstdc++-v3/include/bits/stl_queue.h
+++ b/libstdc++-v3/include/bits/stl_queue.h
@@ -626,6 +626,49 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	  c.insert(c.end(), __first, __last);
 	  std::make_heap(c.begin(), c.end(), comp);
 	}
+
+      // _GLIBCXX_RESOLVE_LIB_DEFECTS
+      // 3506. Missing allocator-extended constructors for priority_queue
+      template<typename _InputIterator, typename _Alloc,
+	       typename = std::_RequireInputIter<_InputIterator>,
+	       typename _Requires = _Uses<_Alloc>>
+	priority_queue(_InputIterator __first, _InputIterator __last,
+		       const _Alloc& __alloc)
+	: c(__first, __last, __alloc), comp()
+	{ std::make_heap(c.begin(), c.end(), comp); }
+
+      template<typename _InputIterator, typename _Alloc,
+	       typename = std::_RequireInputIter<_InputIterator>,
+	       typename _Requires = _Uses<_Alloc>>
+	priority_queue(_InputIterator __first, _InputIterator __last,
+		       const _Compare& __x, const _Alloc& __alloc)
+	: c(__first, __last, __alloc), comp(__x)
+	{ std::make_heap(c.begin(), c.end(), comp); }
+
+      template<typename _InputIterator, typename _Alloc,
+	       typename = std::_RequireInputIter<_InputIterator>,
+	       typename _Requires = _Uses<_Alloc>>
+	priority_queue(_InputIterator __first, _InputIterator __last,
+		       const _Compare& __x, const _Sequence& __s,
+		       const _Alloc& __alloc)
+	: c(__s, __alloc), comp(__x)
+	{
+	  __glibcxx_requires_valid_range(__first, __last);
+	  c.insert(c.end(), __first, __last);
+	  std::make_heap(c.begin(), c.end(), comp);
+	}
+
+      template<typename _InputIterator, typename _Alloc,
+	       typename _Requires = _Uses<_Alloc>>
+	priority_queue(_InputIterator __first, _InputIterator __last,
+		       const _Compare& __x, _Sequence&& __s,
+		       const _Alloc& __alloc)
+	: c(std::move(__s), __alloc), comp(__x)
+	{
+	  __glibcxx_requires_valid_range(__first, __last);
+	  c.insert(c.end(), __first, __last);
+	  std::make_heap(c.begin(), c.end(), comp);
+	}
 #endif
 
       /**
diff --git a/libstdc++-v3/testsuite/23_containers/priority_queue/lwg3506.cc b/libstdc++-v3/testsuite/23_containers/priority_queue/lwg3506.cc
new file mode 100644
index 00000000000..c9c803df8d2
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/priority_queue/lwg3506.cc
@@ -0,0 +1,54 @@
+// { dg-do run { target c++11 } }
+
+#include <queue>
+#include <testsuite_hooks.h>
+#include <testsuite_allocator.h>
+
+void
+test_lwg3506()
+{
+  // LWG 3506 Missing allocator-extended constructors for priority_queue
+
+  using Alloc = __gnu_test::uneq_allocator<int>;
+
+  using Container = std::vector<int, Alloc>;
+
+  struct Queue : std::priority_queue<int, Container>
+  {
+    using priority_queue::priority_queue;
+
+    Alloc get_allocator() const { return c.get_allocator(); }
+  };
+
+  using Compare = Queue::value_compare;
+
+  const Alloc a1(1), a2(2), a3(3), a4(4);
+  const int vals[] = { 5, 3, 9, 1, 7 };
+  Container cont({ 20, 30, 40 }, Alloc(99));
+
+  Queue q1(vals, vals+5, a1);
+  VERIFY( q1.get_allocator() == a1 );
+  VERIFY( q1.size() == 5 );
+  VERIFY( q1.top() == 9 );
+
+  Queue q2(vals, vals+5, Compare(), a2);
+  VERIFY( q2.get_allocator() == a2 );
+  VERIFY( q2.size() == 5 );
+  VERIFY( q2.top() == 9 );
+
+  Queue q3(vals, vals+5, Compare(), cont, a3);
+  VERIFY( q3.get_allocator() == a3 );
+  VERIFY( q3.size() == 8 );
+  VERIFY( q3.top() == 40 );
+
+  Queue q4(vals, vals+5, Compare(), std::move(cont), a4);
+  VERIFY( q4.get_allocator() == a4 );
+  VERIFY( q4.size() == 8 );
+  VERIFY( q4.top() == 40 );
+  VERIFY( cont.empty() );
+}
+
+int main()
+{
+  test_lwg3506();
+}