PR78134 fix return types of heterogeneous lookup functions

	PR libstdc++/78134
	* include/bits/stl_map.h (map::lower_bound, map::upper_bound)
	(map::equal_range): Fix return type of heterogeneous overloads.
	* include/bits/stl_multimap.h (multimap::lower_bound)
	(multimap::upper_bound, multimap::equal_range): Likewise.
	* include/bits/stl_multiset.h (multiset::lower_bound)
	(multiset::upper_bound, multiset::equal_range): Likewise.
	* include/bits/stl_set.h (set::lower_bound, set::upper_bound)
	(set::equal_range): Likewise.
	* testsuite/23_containers/map/operations/2.cc
	* testsuite/23_containers/multimap/operations/2.cc
	* testsuite/23_containers/multiset/operations/2.cc
	* testsuite/23_containers/set/operations/2.cc

From-SVN: r244318

9 files changed, 158 insertions, 68 deletions

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index b52d6df..35fbb95 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,5 +1,19 @@
 2017-01-11  Jonathan Wakely  <jwakely@redhat.com>
 
+	PR libstdc++/78134
+	* include/bits/stl_map.h (map::lower_bound, map::upper_bound)
+	(map::equal_range): Fix return type of heterogeneous overloads.
+	* include/bits/stl_multimap.h (multimap::lower_bound)
+	(multimap::upper_bound, multimap::equal_range): Likewise.
+	* include/bits/stl_multiset.h (multiset::lower_bound)
+	(multiset::upper_bound, multiset::equal_range): Likewise.
+	* include/bits/stl_set.h (set::lower_bound, set::upper_bound)
+	(set::equal_range): Likewise.
+	* testsuite/23_containers/map/operations/2.cc
+	* testsuite/23_containers/multimap/operations/2.cc
+	* testsuite/23_containers/multiset/operations/2.cc
+	* testsuite/23_containers/set/operations/2.cc
+
 	PR libstdc++/78273
 	* include/bits/stl_map.h (map::count<_Kt>(const _Kt&)): Don't assume
 	the heterogeneous comparison can only find one match.
diff --git a/libstdc++-v3/include/bits/stl_map.h b/libstdc++-v3/include/bits/stl_map.h
index 91b80d9..194ce42 100644
--- a/libstdc++-v3/include/bits/stl_map.h
+++ b/libstdc++-v3/include/bits/stl_map.h
@@ -1218,8 +1218,8 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       template<typename _Kt>
 	auto
 	lower_bound(const _Kt& __x)
-	-> decltype(_M_t._M_lower_bound_tr(__x))
-	{ return _M_t._M_lower_bound_tr(__x); }
+	-> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
+	{ return iterator(_M_t._M_lower_bound_tr(__x)); }
 #endif
       //@}
 
@@ -1243,8 +1243,8 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       template<typename _Kt>
 	auto
 	lower_bound(const _Kt& __x) const
-	-> decltype(_M_t._M_lower_bound_tr(__x))
-	{ return _M_t._M_lower_bound_tr(__x); }
+	-> decltype(const_iterator(_M_t._M_lower_bound_tr(__x)))
+	{ return const_iterator(_M_t._M_lower_bound_tr(__x)); }
 #endif
       //@}
 
@@ -1263,8 +1263,8 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       template<typename _Kt>
 	auto
 	upper_bound(const _Kt& __x)
-	-> decltype(_M_t._M_upper_bound_tr(__x))
-	{ return _M_t._M_upper_bound_tr(__x); }
+	-> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
+	{ return iterator(_M_t._M_upper_bound_tr(__x)); }
 #endif
       //@}
 
@@ -1283,8 +1283,8 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       template<typename _Kt>
 	auto
 	upper_bound(const _Kt& __x) const
-	-> decltype(_M_t._M_upper_bound_tr(__x))
-	{ return _M_t._M_upper_bound_tr(__x); }
+	-> decltype(const_iterator(_M_t._M_upper_bound_tr(__x)))
+	{ return const_iterator(_M_t._M_upper_bound_tr(__x)); }
 #endif
       //@}
 
@@ -1312,8 +1312,8 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       template<typename _Kt>
 	auto
 	equal_range(const _Kt& __x)
-	-> decltype(_M_t._M_equal_range_tr(__x))
-	{ return _M_t._M_equal_range_tr(__x); }
+	-> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
+	{ return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
 #endif
       //@}
 
@@ -1341,8 +1341,12 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       template<typename _Kt>
 	auto
 	equal_range(const _Kt& __x) const
-	-> decltype(_M_t._M_equal_range_tr(__x))
-	{ return _M_t._M_equal_range_tr(__x); }
+	-> decltype(pair<const_iterator, const_iterator>(
+	      _M_t._M_equal_range_tr(__x)))
+	{
+	  return pair<const_iterator, const_iterator>(
+	      _M_t._M_equal_range_tr(__x));
+	}
 #endif
       //@}
 
diff --git a/libstdc++-v3/include/bits/stl_multimap.h b/libstdc++-v3/include/bits/stl_multimap.h
index 98af1ba..8b37de9 100644
--- a/libstdc++-v3/include/bits/stl_multimap.h
+++ b/libstdc++-v3/include/bits/stl_multimap.h
@@ -887,8 +887,8 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       template<typename _Kt>
 	auto
 	lower_bound(const _Kt& __x)
-	-> decltype(_M_t._M_lower_bound_tr(__x))
-	{ return _M_t._M_lower_bound_tr(__x); }
+	-> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
+	{ return iterator(_M_t._M_lower_bound_tr(__x)); }
 #endif
       //@}
 
@@ -912,8 +912,8 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       template<typename _Kt>
 	auto
 	lower_bound(const _Kt& __x) const
-	-> decltype(_M_t._M_lower_bound_tr(__x))
-	{ return _M_t._M_lower_bound_tr(__x); }
+	-> decltype(const_iterator(_M_t._M_lower_bound_tr(__x)))
+	{ return const_iterator(_M_t._M_lower_bound_tr(__x)); }
 #endif
       //@}
 
@@ -932,8 +932,8 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       template<typename _Kt>
 	auto
 	upper_bound(const _Kt& __x)
-	-> decltype(_M_t._M_upper_bound_tr(__x))
-	{ return _M_t._M_upper_bound_tr(__x); }
+	-> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
+	{ return iterator(_M_t._M_upper_bound_tr(__x)); }
 #endif
       //@}
 
@@ -952,8 +952,8 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       template<typename _Kt>
 	auto
 	upper_bound(const _Kt& __x) const
-	-> decltype(_M_t._M_upper_bound_tr(__x))
-	{ return _M_t._M_upper_bound_tr(__x); }
+	-> decltype(const_iterator(_M_t._M_upper_bound_tr(__x)))
+	{ return const_iterator(_M_t._M_upper_bound_tr(__x)); }
 #endif
       //@}
 
@@ -979,8 +979,8 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       template<typename _Kt>
 	auto
 	equal_range(const _Kt& __x)
-	-> decltype(_M_t._M_equal_range_tr(__x))
-	{ return _M_t._M_equal_range_tr(__x); }
+	-> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
+	{ return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
 #endif
       //@}
 
@@ -1006,8 +1006,12 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       template<typename _Kt>
 	auto
 	equal_range(const _Kt& __x) const
-	-> decltype(_M_t._M_equal_range_tr(__x))
-	{ return _M_t._M_equal_range_tr(__x); }
+	-> decltype(pair<const_iterator, const_iterator>(
+	      _M_t._M_equal_range_tr(__x)))
+	{
+	  return pair<const_iterator, const_iterator>(
+	      _M_t._M_equal_range_tr(__x));
+	}
 #endif
       //@}
 
diff --git a/libstdc++-v3/include/bits/stl_multiset.h b/libstdc++-v3/include/bits/stl_multiset.h
index e2bc4f2..871369c 100644
--- a/libstdc++-v3/include/bits/stl_multiset.h
+++ b/libstdc++-v3/include/bits/stl_multiset.h
@@ -785,14 +785,14 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       template<typename _Kt>
 	auto
 	lower_bound(const _Kt& __x)
-	-> decltype(_M_t._M_lower_bound_tr(__x))
-	{ return _M_t._M_lower_bound_tr(__x); }
+	-> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
+	{ return iterator(_M_t._M_lower_bound_tr(__x)); }
 
       template<typename _Kt>
 	auto
 	lower_bound(const _Kt& __x) const
-	-> decltype(_M_t._M_lower_bound_tr(__x))
-	{ return _M_t._M_lower_bound_tr(__x); }
+	-> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
+	{ return iterator(_M_t._M_lower_bound_tr(__x)); }
 #endif
       //@}
 
@@ -815,14 +815,14 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       template<typename _Kt>
 	auto
 	upper_bound(const _Kt& __x)
-	-> decltype(_M_t._M_upper_bound_tr(__x))
-	{ return _M_t._M_upper_bound_tr(__x); }
+	-> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
+	{ return iterator(_M_t._M_upper_bound_tr(__x)); }
 
       template<typename _Kt>
 	auto
 	upper_bound(const _Kt& __x) const
-	-> decltype(_M_t._M_upper_bound_tr(__x))
-	{ return _M_t._M_upper_bound_tr(__x); }
+	-> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
+	{ return iterator(_M_t._M_upper_bound_tr(__x)); }
 #endif
       //@}
 
@@ -854,14 +854,14 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       template<typename _Kt>
 	auto
 	equal_range(const _Kt& __x)
-	-> decltype(_M_t._M_equal_range_tr(__x))
-	{ return _M_t._M_equal_range_tr(__x); }
+	-> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
+	{ return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
 
       template<typename _Kt>
 	auto
 	equal_range(const _Kt& __x) const
-	-> decltype(_M_t._M_equal_range_tr(__x))
-	{ return _M_t._M_equal_range_tr(__x); }
+	-> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
+	{ return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
 #endif
       //@}
 
diff --git a/libstdc++-v3/include/bits/stl_set.h b/libstdc++-v3/include/bits/stl_set.h
index ab960f1..3decaff 100644
--- a/libstdc++-v3/include/bits/stl_set.h
+++ b/libstdc++-v3/include/bits/stl_set.h
@@ -804,14 +804,14 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       template<typename _Kt>
 	auto
 	lower_bound(const _Kt& __x)
-	-> decltype(_M_t._M_lower_bound_tr(__x))
-	{ return _M_t._M_lower_bound_tr(__x); }
+	-> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
+	{ return iterator(_M_t._M_lower_bound_tr(__x)); }
 
       template<typename _Kt>
 	auto
 	lower_bound(const _Kt& __x) const
-	-> decltype(_M_t._M_lower_bound_tr(__x))
-	{ return _M_t._M_lower_bound_tr(__x); }
+	-> decltype(const_iterator(_M_t._M_lower_bound_tr(__x)))
+	{ return const_iterator(_M_t._M_lower_bound_tr(__x)); }
 #endif
       //@}
 
@@ -834,14 +834,14 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       template<typename _Kt>
 	auto
 	upper_bound(const _Kt& __x)
-	-> decltype(_M_t._M_upper_bound_tr(__x))
-	{ return _M_t._M_upper_bound_tr(__x); }
+	-> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
+	{ return iterator(_M_t._M_upper_bound_tr(__x)); }
 
       template<typename _Kt>
 	auto
 	upper_bound(const _Kt& __x) const
-	-> decltype(_M_t._M_upper_bound_tr(__x))
-	{ return _M_t._M_upper_bound_tr(__x); }
+	-> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
+	{ return const_iterator(_M_t._M_upper_bound_tr(__x)); }
 #endif
       //@}
 
@@ -873,14 +873,14 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       template<typename _Kt>
 	auto
 	equal_range(const _Kt& __x)
-	-> decltype(_M_t._M_equal_range_tr(__x))
-	{ return _M_t._M_equal_range_tr(__x); }
+	-> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
+	{ return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
 
       template<typename _Kt>
 	auto
 	equal_range(const _Kt& __x) const
-	-> decltype(_M_t._M_equal_range_tr(__x))
-	{ return _M_t._M_equal_range_tr(__x); }
+	-> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
+	{ return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
 #endif
       //@}
 
diff --git a/libstdc++-v3/testsuite/23_containers/map/operations/2.cc b/libstdc++-v3/testsuite/23_containers/map/operations/2.cc
index ef4e76b..a301025 100644
--- a/libstdc++-v3/testsuite/23_containers/map/operations/2.cc
+++ b/libstdc++-v3/testsuite/23_containers/map/operations/2.cc
@@ -53,7 +53,7 @@ test01()
   cit = cx.find(2L);
   VERIFY( cit == cx.end() );
 
-  VERIFY( Cmp::count == 0);
+  VERIFY( Cmp::count == 0 );
 
   static_assert(std::is_same<decltype(it), test_type::iterator>::value,
       "find returns iterator");
@@ -76,7 +76,7 @@ test02()
   cn = cx.count(2L);
   VERIFY( cn == 0 );
 
-  VERIFY( Cmp::count == 0);
+  VERIFY( Cmp::count == 0 );
 }
 
 void
@@ -94,7 +94,12 @@ test03()
   cit = cx.lower_bound(2L);
   VERIFY( cit != cx.end() && cit->second == '4' );
 
-  VERIFY( Cmp::count == 0);
+  VERIFY( Cmp::count == 0 );
+
+  static_assert(std::is_same<decltype(it), test_type::iterator>::value,
+      "lower_bound returns iterator");
+  static_assert(std::is_same<decltype(cit), test_type::const_iterator>::value,
+      "const lower_bound returns const_iterator");
 }
 
 void
@@ -112,7 +117,12 @@ test04()
   cit = cx.upper_bound(3L);
   VERIFY( cit == cx.end() );
 
-  VERIFY( Cmp::count == 0);
+  VERIFY( Cmp::count == 0 );
+
+  static_assert(std::is_same<decltype(it), test_type::iterator>::value,
+      "upper_bound returns iterator");
+  static_assert(std::is_same<decltype(cit), test_type::const_iterator>::value,
+      "const upper_bound returns const_iterator");
 }
 
 void
@@ -130,7 +140,14 @@ test05()
   cit = cx.equal_range(2L);
   VERIFY( cit.first == cit.second && cit.first != cx.end() );
 
-  VERIFY( Cmp::count == 0);
+  VERIFY( Cmp::count == 0 );
+
+  using pair = std::pair<test_type::iterator, test_type::iterator>;
+  static_assert(std::is_same<decltype(it), pair>::value,
+      "equal_range returns pair<iterator, iterator>");
+  using cpair = std::pair<test_type::const_iterator, test_type::const_iterator>;
+  static_assert(std::is_same<decltype(cit), cpair>::value,
+      "const equal_range returns pair<const_iterator, const_iterator>");
 }
 
 void
diff --git a/libstdc++-v3/testsuite/23_containers/multimap/operations/2.cc b/libstdc++-v3/testsuite/23_containers/multimap/operations/2.cc
index 06e084d..01a10f6 100644
--- a/libstdc++-v3/testsuite/23_containers/multimap/operations/2.cc
+++ b/libstdc++-v3/testsuite/23_containers/multimap/operations/2.cc
@@ -53,7 +53,7 @@ test01()
   cit = cx.find(2L);
   VERIFY( cit == cx.end() );
 
-  VERIFY( Cmp::count == 0);
+  VERIFY( Cmp::count == 0 );
 
   static_assert(std::is_same<decltype(it), test_type::iterator>::value,
       "find returns iterator");
@@ -76,7 +76,7 @@ test02()
   cn = cx.count(2L);
   VERIFY( cn == 0 );
 
-  VERIFY( Cmp::count == 0);
+  VERIFY( Cmp::count == 0 );
 }
 
 void
@@ -94,7 +94,12 @@ test03()
   cit = cx.lower_bound(2L);
   VERIFY( cit != cx.end() && cit->second == '4' );
 
-  VERIFY( Cmp::count == 0);
+  VERIFY( Cmp::count == 0 );
+
+  static_assert(std::is_same<decltype(it), test_type::iterator>::value,
+      "lower_bound returns iterator");
+  static_assert(std::is_same<decltype(cit), test_type::const_iterator>::value,
+      "const lower_bound returns const_iterator");
 }
 
 void
@@ -112,7 +117,12 @@ test04()
   cit = cx.upper_bound(3L);
   VERIFY( cit == cx.end() );
 
-  VERIFY( Cmp::count == 0);
+  VERIFY( Cmp::count == 0 );
+
+  static_assert(std::is_same<decltype(it), test_type::iterator>::value,
+      "upper_bound returns iterator");
+  static_assert(std::is_same<decltype(cit), test_type::const_iterator>::value,
+      "const upper_bound returns const_iterator");
 }
 
 void
@@ -131,7 +141,14 @@ test05()
   cit = cx.equal_range(2L);
   VERIFY( cit.first == cit.second && cit.first != cx.end() );
 
-  VERIFY( Cmp::count == 0);
+  VERIFY( Cmp::count == 0 );
+
+  using pair = std::pair<test_type::iterator, test_type::iterator>;
+  static_assert(std::is_same<decltype(it), pair>::value,
+      "equal_range returns pair<iterator, iterator>");
+  using cpair = std::pair<test_type::const_iterator, test_type::const_iterator>;
+  static_assert(std::is_same<decltype(cit), cpair>::value,
+      "const equal_range returns pair<const_iterator, const_iterator>");
 }
 
 
diff --git a/libstdc++-v3/testsuite/23_containers/multiset/operations/2.cc b/libstdc++-v3/testsuite/23_containers/multiset/operations/2.cc
index 890016b..9468151 100644
--- a/libstdc++-v3/testsuite/23_containers/multiset/operations/2.cc
+++ b/libstdc++-v3/testsuite/23_containers/multiset/operations/2.cc
@@ -53,7 +53,7 @@ test01()
   cit = cx.find(2L);
   VERIFY( cit == cx.end() );
 
-  VERIFY( Cmp::count == 0);
+  VERIFY( Cmp::count == 0 );
 
   static_assert(std::is_same<decltype(it), test_type::iterator>::value,
       "find returns iterator");
@@ -76,7 +76,7 @@ test02()
   cn = cx.count(2L);
   VERIFY( cn == 0 );
 
-  VERIFY( Cmp::count == 0);
+  VERIFY( Cmp::count == 0 );
 }
 
 void
@@ -94,7 +94,12 @@ test03()
   cit = cx.lower_bound(2L);
   VERIFY( cit != cx.end() && *cit == 3 );
 
-  VERIFY( Cmp::count == 0);
+  VERIFY( Cmp::count == 0 );
+
+  static_assert(std::is_same<decltype(it), test_type::iterator>::value,
+      "lower_bound returns iterator");
+  static_assert(std::is_same<decltype(cit), test_type::const_iterator>::value,
+      "const lower_bound returns const_iterator");
 }
 
 void
@@ -112,7 +117,12 @@ test04()
   cit = cx.upper_bound(5L);
   VERIFY( cit == cx.end() );
 
-  VERIFY( Cmp::count == 0);
+  VERIFY( Cmp::count == 0 );
+
+  static_assert(std::is_same<decltype(it), test_type::iterator>::value,
+      "upper_bound returns iterator");
+  static_assert(std::is_same<decltype(cit), test_type::const_iterator>::value,
+      "const upper_bound returns const_iterator");
 }
 
 void
@@ -131,7 +141,14 @@ test05()
   cit = cx.equal_range(2L);
   VERIFY( cit.first == cit.second && cit.first != cx.end() );
 
-  VERIFY( Cmp::count == 0);
+  VERIFY( Cmp::count == 0 );
+
+  using pair = std::pair<test_type::iterator, test_type::iterator>;
+  static_assert(std::is_same<decltype(it), pair>::value,
+      "equal_range returns pair<iterator, iterator>");
+  using cpair = std::pair<test_type::const_iterator, test_type::const_iterator>;
+  static_assert(std::is_same<decltype(cit), cpair>::value,
+      "const equal_range returns pair<const_iterator, const_iterator>");
 }
 
 
diff --git a/libstdc++-v3/testsuite/23_containers/set/operations/2.cc b/libstdc++-v3/testsuite/23_containers/set/operations/2.cc
index aef808d..acddb18 100644
--- a/libstdc++-v3/testsuite/23_containers/set/operations/2.cc
+++ b/libstdc++-v3/testsuite/23_containers/set/operations/2.cc
@@ -53,7 +53,7 @@ test01()
   cit = cx.find(2L);
   VERIFY( cit == cx.end() );
 
-  VERIFY( Cmp::count == 0);
+  VERIFY( Cmp::count == 0 );
 
   static_assert(std::is_same<decltype(it), test_type::iterator>::value,
       "find returns iterator");
@@ -76,7 +76,7 @@ test02()
   cn = cx.count(2L);
   VERIFY( cn == 0 );
 
-  VERIFY( Cmp::count == 0);
+  VERIFY( Cmp::count == 0 );
 }
 
 void
@@ -94,7 +94,12 @@ test03()
   cit = cx.lower_bound(2L);
   VERIFY( cit != cx.end() && *cit == 3 );
 
-  VERIFY( Cmp::count == 0);
+  VERIFY( Cmp::count == 0 );
+
+  static_assert(std::is_same<decltype(it), test_type::iterator>::value,
+      "lower_bound returns iterator");
+  static_assert(std::is_same<decltype(cit), test_type::const_iterator>::value,
+      "const lower_bound returns const_iterator");
 }
 
 void
@@ -112,7 +117,12 @@ test04()
   cit = cx.upper_bound(5L);
   VERIFY( cit == cx.end() );
 
-  VERIFY( Cmp::count == 0);
+  VERIFY( Cmp::count == 0 );
+
+  static_assert(std::is_same<decltype(it), test_type::iterator>::value,
+      "upper_bound returns iterator");
+  static_assert(std::is_same<decltype(cit), test_type::const_iterator>::value,
+      "const upper_bound returns const_iterator");
 }
 
 void
@@ -130,7 +140,14 @@ test05()
   cit = cx.equal_range(2L);
   VERIFY( cit.first == cit.second && cit.first != cx.end() );
 
-  VERIFY( Cmp::count == 0);
+  VERIFY( Cmp::count == 0 );
+
+  using pair = std::pair<test_type::iterator, test_type::iterator>;
+  static_assert(std::is_same<decltype(it), pair>::value,
+      "equal_range returns pair<iterator, iterator>");
+  using cpair = std::pair<test_type::const_iterator, test_type::const_iterator>;
+  static_assert(std::is_same<decltype(cit), cpair>::value,
+      "const equal_range returns pair<const_iterator, const_iterator>");
 }
 
 void