Fix return type of heterogeneous find for sets

	PR libstdc++/68190
	* include/bits/stl_multiset.h (multiset::find): Fix return types.
	* include/bits/stl_set.h (set::find): Likewise.
	* testsuite/23_containers/map/operations/2.cc: Test find return types.
	* testsuite/23_containers/multimap/operations/2.cc: Likewise.
	* testsuite/23_containers/multiset/operations/2.cc: Likewise.
	* testsuite/23_containers/set/operations/2.cc: Likewise.

From-SVN: r230113

libstdc++-v3/ChangeLog

 2015-11-10  Jonathan Wakely  <jwakely@redhat.com>
 
+	PR libstdc++/68190
+	* include/bits/stl_multiset.h (multiset::find): Fix return types.
+	* include/bits/stl_set.h (set::find): Likewise.
+	* testsuite/23_containers/map/operations/2.cc: Test find return types.
+	* testsuite/23_containers/multimap/operations/2.cc: Likewise.
+	* testsuite/23_containers/multiset/operations/2.cc: Likewise.
+	* testsuite/23_containers/set/operations/2.cc: Likewise.
+
 	* doc/xml/manual/status_cxx2017.xml: Update.
 	* doc/html/*: Regenerate.
 

libstdc++-v3/include/bits/stl_multiset.h

@@ -680,13 +680,15 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
 #if __cplusplus > 201103L
       template<typename _Kt>
 	auto
-	find(const _Kt& __x) -> decltype(_M_t._M_find_tr(__x))
-	{ return _M_t._M_find_tr(__x); }
+	find(const _Kt& __x)
+	-> decltype(iterator{_M_t._M_find_tr(__x)})
+	{ return iterator{_M_t._M_find_tr(__x)}; }
 
       template<typename _Kt>
 	auto
-	find(const _Kt& __x) const -> decltype(_M_t._M_find_tr(__x))
-	{ return _M_t._M_find_tr(__x); }
+	find(const _Kt& __x) const
+	-> decltype(const_iterator{_M_t._M_find_tr(__x)})
+	{ return const_iterator{_M_t._M_find_tr(__x)}; }
 #endif
       //@}
 

libstdc++-v3/include/bits/stl_set.h

@@ -699,13 +699,15 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
 #if __cplusplus > 201103L
       template<typename _Kt>
 	auto
-	find(const _Kt& __x) -> decltype(_M_t._M_find_tr(__x))
-	{ return _M_t._M_find_tr(__x); }
+	find(const _Kt& __x)
+	-> decltype(iterator{_M_t._M_find_tr(__x)})
+	{ return iterator{_M_t._M_find_tr(__x)}; }
 
       template<typename _Kt>
 	auto
-	find(const _Kt& __x) const -> decltype(_M_t._M_find_tr(__x))
-	{ return _M_t._M_find_tr(__x); }
+	find(const _Kt& __x) const
+	-> decltype(const_iterator{_M_t._M_find_tr(__x)})
+	{ return const_iterator{_M_t._M_find_tr(__x)}; }
 #endif
       //@}
 

libstdc++-v3/testsuite/23_containers/map/operations/2.cc

@@ -54,6 +54,11 @@ test01()
   VERIFY( cit == cx.end() );
 
   VERIFY( Cmp::count == 0);
+
+  static_assert(std::is_same<decltype(it), test_type::iterator>::value,
+      "find returns iterator");
+  static_assert(std::is_same<decltype(cit), test_type::const_iterator>::value,
+      "const find returns const_iterator");
 }
 
 void

libstdc++-v3/testsuite/23_containers/multimap/operations/2.cc

@@ -54,6 +54,11 @@ test01()
   VERIFY( cit == cx.end() );
 
   VERIFY( Cmp::count == 0);
+
+  static_assert(std::is_same<decltype(it), test_type::iterator>::value,
+      "find returns iterator");
+  static_assert(std::is_same<decltype(cit), test_type::const_iterator>::value,
+      "const find returns const_iterator");
 }
 
 void

libstdc++-v3/testsuite/23_containers/multiset/operations/2.cc

@@ -54,6 +54,11 @@ test01()
   VERIFY( cit == cx.end() );
 
   VERIFY( Cmp::count == 0);
+
+  static_assert(std::is_same<decltype(it), test_type::iterator>::value,
+      "find returns iterator");
+  static_assert(std::is_same<decltype(cit), test_type::const_iterator>::value,
+      "const find returns const_iterator");
 }
 
 void

libstdc++-v3/testsuite/23_containers/set/operations/2.cc

@@ -54,6 +54,11 @@ test01()
   VERIFY( cit == cx.end() );
 
   VERIFY( Cmp::count == 0);
+
+  static_assert(std::is_same<decltype(it), test_type::iterator>::value,
+      "find returns iterator");
+  static_assert(std::is_same<decltype(cit), test_type::const_iterator>::value,
+      "const find returns const_iterator");
 }
 
 void