libstdc++: Make _GLIBCXX_NODISCARD work for C++11 and C++14

The _GLIBCXX_NODISCARD macro only expands to [[__nodiscard__]] for C++17
and later, but all supported compilers will allow us to use that for
C++11 and C++14 too. Enable it for those older standards, to give
improved diagnostics for users of those older standards.

libstdc++-v3/ChangeLog:

	* include/bits/c++config (_GLIBCXX_NODISCARD): Expand for C++11
	and C++14.
	* testsuite/22_locale/locale/cons/12438.cc: Adjust dg-warning to
	expect nodiscard warnings for C++11 and C++14 as well.
	* testsuite/22_locale/locale/operations/2.cc: Likewise.
	* testsuite/25_algorithms/equal/debug/1_neg.cc: Likewise.
	* testsuite/25_algorithms/equal/debug/2_neg.cc: Likewise.
	* testsuite/25_algorithms/equal/debug/3_neg.cc: Likewise.
	* testsuite/25_algorithms/find_first_of/concept_check_1.cc:
	Likewise.
	* testsuite/25_algorithms/is_permutation/2.cc: Likewise.
	* testsuite/25_algorithms/lexicographical_compare/71545.cc:
	Likewise.
	* testsuite/25_algorithms/lower_bound/33613.cc: Likewise.
	* testsuite/25_algorithms/lower_bound/debug/irreflexive.cc:
	Likewise.
	* testsuite/25_algorithms/lower_bound/debug/partitioned_neg.cc:
	Likewise.
	* testsuite/25_algorithms/lower_bound/debug/partitioned_pred_neg.cc: Likewise.
	* testsuite/25_algorithms/minmax/3.cc: Likewise.
	* testsuite/25_algorithms/search/78346.cc: Likewise.
	* testsuite/25_algorithms/search_n/58358.cc: Likewise.
	* testsuite/25_algorithms/unique/1.cc: Likewise.
	* testsuite/25_algorithms/unique/11480.cc: Likewise.
	* testsuite/25_algorithms/upper_bound/33613.cc: Likewise.
	* testsuite/25_algorithms/upper_bound/debug/partitioned_neg.cc:
	Likewise.
	* testsuite/25_algorithms/upper_bound/debug/partitioned_pred_neg.cc: Likewise.
	* testsuite/27_io/ios_base/types/fmtflags/bitmask_operators.cc:
	Likewise.
	* testsuite/27_io/ios_base/types/iostate/bitmask_operators.cc:
	Likewise.
	* testsuite/27_io/ios_base/types/openmode/bitmask_operators.cc:
	Likewise.
	* testsuite/ext/concept_checks.cc: Likewise.
	* testsuite/ext/is_heap/47709.cc: Likewise.
	* testsuite/ext/is_sorted/cxx0x.cc: Likewise.

27 files changed, 39 insertions, 41 deletions

diff --git a/libstdc++-v3/include/bits/c++config b/libstdc++-v3/include/bits/c++config
index 1076803..236906d 100644
--- a/libstdc++-v3/include/bits/c++config
+++ b/libstdc++-v3/include/bits/c++config
@@ -169,7 +169,7 @@
 #endif
 
 // Macro to warn about unused results.
-#if __cplusplus >= 201703L
+#if __cplusplus >= 201103L
 # define _GLIBCXX_NODISCARD [[__nodiscard__]]
 #else
 # define _GLIBCXX_NODISCARD
diff --git a/libstdc++-v3/testsuite/22_locale/locale/cons/12438.cc b/libstdc++-v3/testsuite/22_locale/locale/cons/12438.cc
index 4838e1b..72b6b15 100644
--- a/libstdc++-v3/testsuite/22_locale/locale/cons/12438.cc
+++ b/libstdc++-v3/testsuite/22_locale/locale/cons/12438.cc
@@ -45,7 +45,7 @@ void test01(int iters)
 	  locale loc2 = locale("");
 	  VERIFY( !has_facet<MyFacet>(loc2) );
 	  
-	  loc1.combine<MyFacet>(loc2); // { dg-warning "nodiscard" "" { target c++17 } }
+	  loc1.combine<MyFacet>(loc2); // { dg-warning "nodiscard" "" { target c++11 } }
 	  VERIFY( false );
 	}
       catch (std::runtime_error&)
diff --git a/libstdc++-v3/testsuite/22_locale/locale/operations/2.cc b/libstdc++-v3/testsuite/22_locale/locale/operations/2.cc
index 917adec..c0a6613 100644
--- a/libstdc++-v3/testsuite/22_locale/locale/operations/2.cc
+++ b/libstdc++-v3/testsuite/22_locale/locale/operations/2.cc
@@ -48,7 +48,7 @@ void test02()
   // Derivation, MF check.
   locale loc_gnu(loc_c, new gnu_collate);
   gnu_count = 0;
-  loc_gnu(s01, s02); // { dg-warning "nodiscard" "" { target c++17 } }
+  loc_gnu(s01, s02); // { dg-warning "nodiscard" "" { target c++11 } }
   VERIFY( gnu_count == 1 );
 }
 
diff --git a/libstdc++-v3/testsuite/25_algorithms/equal/debug/1_neg.cc b/libstdc++-v3/testsuite/25_algorithms/equal/debug/1_neg.cc
index f932859..38060b1 100644
--- a/libstdc++-v3/testsuite/25_algorithms/equal/debug/1_neg.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/equal/debug/1_neg.cc
@@ -27,7 +27,7 @@ test01()
   std::vector<int> vect;
   vect.push_back(1);
   std::equal(vect.end(), vect.begin(), vect.begin());
-  // { dg-warning "ignoring return value" "" { target c++17 } 29 }
+  // { dg-warning "ignoring return value" "" { target c++11 } 29 }
 }
 
 int
diff --git a/libstdc++-v3/testsuite/25_algorithms/equal/debug/2_neg.cc b/libstdc++-v3/testsuite/25_algorithms/equal/debug/2_neg.cc
index 2e9134a..5148571 100644
--- a/libstdc++-v3/testsuite/25_algorithms/equal/debug/2_neg.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/equal/debug/2_neg.cc
@@ -27,7 +27,7 @@ test01()
   std::vector<int> v1, v2;
   v1.push_back(1);
   std::equal(v1.begin(), v1.end(), v2.begin());
-  // { dg-warning "ignoring return value" "" { target c++17 } 29 }
+  // { dg-warning "ignoring return value" "" { target c++11 } 29 }
 }
 
 int
diff --git a/libstdc++-v3/testsuite/25_algorithms/equal/debug/3_neg.cc b/libstdc++-v3/testsuite/25_algorithms/equal/debug/3_neg.cc
index 425e7aa..5a17630 100644
--- a/libstdc++-v3/testsuite/25_algorithms/equal/debug/3_neg.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/equal/debug/3_neg.cc
@@ -33,7 +33,7 @@ test01()
   l2.push_back(2);
 
   std::equal(++l1.begin(), l1.end(), ++l2.begin());
-  // { dg-warning "ignoring return value" "" { target c++17 } 35 }
+  // { dg-warning "ignoring return value" "" { target c++11 } 35 }
 }
 
 int
diff --git a/libstdc++-v3/testsuite/25_algorithms/find_first_of/concept_check_1.cc b/libstdc++-v3/testsuite/25_algorithms/find_first_of/concept_check_1.cc
index a970cd4..33f3b42 100644
--- a/libstdc++-v3/testsuite/25_algorithms/find_first_of/concept_check_1.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/find_first_of/concept_check_1.cc
@@ -37,7 +37,7 @@ class2 b;
 void test01()
 {
   std::find_first_of(&a, &a, &b, &b, comp);
-  // { dg-warning "ignoring return value" "" { target c++17 } 39 }
+  // { dg-warning "ignoring return value" "" { target c++11 } 39 }
 }
 
 int main()
diff --git a/libstdc++-v3/testsuite/25_algorithms/is_permutation/2.cc b/libstdc++-v3/testsuite/25_algorithms/is_permutation/2.cc
index ab0610c..3561c2e 100644
--- a/libstdc++-v3/testsuite/25_algorithms/is_permutation/2.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/is_permutation/2.cc
@@ -103,7 +103,7 @@ void test02()
   int arr[] = { 11, 22, 33 };
   using namespace std;
   is_permutation(begin(arr0), end(arr0), begin(arr), end(arr), thrower);
-  // { dg-warning "ignoring return value" "" { target c++17 } 105 }
+  // { dg-warning "ignoring return value" "" { target c++11 } 105 }
 }
 
 int main()
diff --git a/libstdc++-v3/testsuite/25_algorithms/lexicographical_compare/71545.cc b/libstdc++-v3/testsuite/25_algorithms/lexicographical_compare/71545.cc
index 9f666ca..9f50714 100644
--- a/libstdc++-v3/testsuite/25_algorithms/lexicographical_compare/71545.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/lexicographical_compare/71545.cc
@@ -33,5 +33,5 @@ int main()
   X x[1];
   int i[1];
   std::lexicographical_compare(x, x+1, i, i+1);
-  // { dg-warning "ignoring return value" "" { target c++17 } 35 }
+  // { dg-warning "ignoring return value" "" { target c++11 } 35 }
 }
diff --git a/libstdc++-v3/testsuite/25_algorithms/lower_bound/33613.cc b/libstdc++-v3/testsuite/25_algorithms/lower_bound/33613.cc
index fa42b82..adb04d3 100644
--- a/libstdc++-v3/testsuite/25_algorithms/lower_bound/33613.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/lower_bound/33613.cc
@@ -33,5 +33,5 @@ bool ab(A, B);
 void test01(A* a, B b)
 {
   std::lower_bound(a, a, b, ab);
-  // { dg-warning "ignoring return value" "" { target c++17 } 35 }
+  // { dg-warning "ignoring return value" "" { target c++11 } 35 }
 }
diff --git a/libstdc++-v3/testsuite/25_algorithms/lower_bound/debug/irreflexive.cc b/libstdc++-v3/testsuite/25_algorithms/lower_bound/debug/irreflexive.cc
index 41a6028..d85459a 100644
--- a/libstdc++-v3/testsuite/25_algorithms/lower_bound/debug/irreflexive.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/lower_bound/debug/irreflexive.cc
@@ -44,5 +44,5 @@ void test01()
 {
   A as[] = { 0, 1, 2, 3 };
   std::lower_bound(as, as + 4, 1, A_int_comparer());
-  // { dg-warning "ignoring return value" "" { target c++17 } 46 }
+  // { dg-warning "ignoring return value" "" { target c++11 } 46 }
 }
diff --git a/libstdc++-v3/testsuite/25_algorithms/lower_bound/debug/partitioned_neg.cc b/libstdc++-v3/testsuite/25_algorithms/lower_bound/debug/partitioned_neg.cc
index bc01d81..34a6dbc 100644
--- a/libstdc++-v3/testsuite/25_algorithms/lower_bound/debug/partitioned_neg.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/lower_bound/debug/partitioned_neg.cc
@@ -36,7 +36,7 @@ void test01()
 {
   A as[] = { 0, 1, 2, 0, 2, 3 };
   std::lower_bound(as, as + 6, A(1));
-  // { dg-warning "ignoring return value" "" { target c++17 } 38 }
+  // { dg-warning "ignoring return value" "" { target c++11 } 38 }
 }
 
 int
diff --git a/libstdc++-v3/testsuite/25_algorithms/lower_bound/debug/partitioned_pred_neg.cc b/libstdc++-v3/testsuite/25_algorithms/lower_bound/debug/partitioned_pred_neg.cc
index f860df9..2e7dec0 100644
--- a/libstdc++-v3/testsuite/25_algorithms/lower_bound/debug/partitioned_pred_neg.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/lower_bound/debug/partitioned_pred_neg.cc
@@ -24,7 +24,7 @@ void test01()
 {
   int as[] = { 0, 1, 0, 2, 3 };
   std::lower_bound(as, as + 5, 1, std::less<int>());
-  // { dg-warning "ignoring return value" "" { target c++17 } 26 }
+  // { dg-warning "ignoring return value" "" { target c++11 } 26 }
 }
 
 
diff --git a/libstdc++-v3/testsuite/25_algorithms/minmax/3.cc b/libstdc++-v3/testsuite/25_algorithms/minmax/3.cc
index a6620b9..63607cd 100644
--- a/libstdc++-v3/testsuite/25_algorithms/minmax/3.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/minmax/3.cc
@@ -43,7 +43,7 @@ int compare_counter::count = 0;
 void test01()
 {
   std::minmax({1, 2, 3, 4, 5, 6, 7, 8}, compare_counter());
-  // { dg-warning "ignoring return value" "" { target c++17 } 45 }
+  // { dg-warning "ignoring return value" "" { target c++11 } 45 }
 
   // If N is the number of arguments in the minmax function call, 
   // 25.3.7 specifies that at most 3N/2 comparisons are allowed.
diff --git a/libstdc++-v3/testsuite/25_algorithms/search/78346.cc b/libstdc++-v3/testsuite/25_algorithms/search/78346.cc
index e6f3956..18fc946 100644
--- a/libstdc++-v3/testsuite/25_algorithms/search/78346.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/search/78346.cc
@@ -109,7 +109,7 @@ test01()
 {
   value s[] = { 0, 1, 2, 3, 4, 5 };
   std::search(s, s+6, stashing_iterator(s), stashing_iterator(s+4));
-  // { dg-warning "ignoring return value" "" { target c++17 } 111 }
+  // { dg-warning "ignoring return value" "" { target c++11 } 111 }
 }
 
 int
diff --git a/libstdc++-v3/testsuite/25_algorithms/search_n/58358.cc b/libstdc++-v3/testsuite/25_algorithms/search_n/58358.cc
index 651fd86..b16e8c1 100644
--- a/libstdc++-v3/testsuite/25_algorithms/search_n/58358.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/search_n/58358.cc
@@ -29,7 +29,7 @@ void test01()
   int count = 0;
   std::search_n(a.begin(), a.end(), 10, 1,
 		[&count](int t, int u) { ++count; return t == u; });
-  // { dg-warning "ignoring return value" "" { target c++17 } 30 }
+  // { dg-warning "ignoring return value" "" { target c++11 } 30 }
   VERIFY( count <= 11 );
 }
 
diff --git a/libstdc++-v3/testsuite/25_algorithms/unique/1.cc b/libstdc++-v3/testsuite/25_algorithms/unique/1.cc
index 698c370..f5e3c97 100644
--- a/libstdc++-v3/testsuite/25_algorithms/unique/1.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/unique/1.cc
@@ -27,6 +27,6 @@ int main()
   using namespace std;
   list<int> menge;
   unique (menge.begin(), menge.end());
-  // { dg-warning "ignoring return value" "" { target c++17 } 29 }
+  // { dg-warning "ignoring return value" "" { target c++11 } 29 }
   return 0;
 }
diff --git a/libstdc++-v3/testsuite/25_algorithms/unique/11480.cc b/libstdc++-v3/testsuite/25_algorithms/unique/11480.cc
index a008fc5..8c11b4c 100644
--- a/libstdc++-v3/testsuite/25_algorithms/unique/11480.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/unique/11480.cc
@@ -31,7 +31,7 @@ bool compare(int a, int b)
 // libstdc++/11480
 void test01()
 {
-  std::unique(a, a+10, compare); // { dg-warning "ignoring return value" "" { target c++17 } }
+  std::unique(a, a+10, compare); // { dg-warning "ignoring return value" "" { target c++11 } }
   VERIFY( compare_count == 9 );
 }
 
diff --git a/libstdc++-v3/testsuite/25_algorithms/upper_bound/33613.cc b/libstdc++-v3/testsuite/25_algorithms/upper_bound/33613.cc
index 19453a3..e9eabef 100644
--- a/libstdc++-v3/testsuite/25_algorithms/upper_bound/33613.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/upper_bound/33613.cc
@@ -33,5 +33,5 @@ bool ba(B, A);
 void test01(A* a, B b)
 {
   std::upper_bound(a, a, b, ba);
-  // { dg-warning "ignoring return value" "" { target c++17 } 35 }
+  // { dg-warning "ignoring return value" "" { target c++11 } 35 }
 }
diff --git a/libstdc++-v3/testsuite/25_algorithms/upper_bound/debug/partitioned_neg.cc b/libstdc++-v3/testsuite/25_algorithms/upper_bound/debug/partitioned_neg.cc
index 630357d..a48a826 100644
--- a/libstdc++-v3/testsuite/25_algorithms/upper_bound/debug/partitioned_neg.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/upper_bound/debug/partitioned_neg.cc
@@ -36,7 +36,7 @@ void test01()
 {
   A as[] = { 0, 2, 1, 3, 4, 5 };
   std::upper_bound(as, as + 6, A(1));
-  // { dg-warning "ignoring return value" "" { target c++17 } 38 }
+  // { dg-warning "ignoring return value" "" { target c++11 } 38 }
 }
 
 int
diff --git a/libstdc++-v3/testsuite/25_algorithms/upper_bound/debug/partitioned_pred_neg.cc b/libstdc++-v3/testsuite/25_algorithms/upper_bound/debug/partitioned_pred_neg.cc
index 5beab7d..3e69a24 100644
--- a/libstdc++-v3/testsuite/25_algorithms/upper_bound/debug/partitioned_pred_neg.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/upper_bound/debug/partitioned_pred_neg.cc
@@ -24,7 +24,7 @@ void test01()
 {
   int as[] = { 0, 2, 1, 3, 4 };
   std::upper_bound(as, as + 5, 1, std::less<int>());
-  // { dg-warning "ignoring return value" "" { target c++17 } 26 }
+  // { dg-warning "ignoring return value" "" { target c++11 } 26 }
 }
 
 
diff --git a/libstdc++-v3/testsuite/27_io/ios_base/types/fmtflags/bitmask_operators.cc b/libstdc++-v3/testsuite/27_io/ios_base/types/fmtflags/bitmask_operators.cc
index 604d2aa..3cf8ebe 100644
--- a/libstdc++-v3/testsuite/27_io/ios_base/types/fmtflags/bitmask_operators.cc
+++ b/libstdc++-v3/testsuite/27_io/ios_base/types/fmtflags/bitmask_operators.cc
@@ -27,7 +27,7 @@ int main()
 {
   __gnu_test::bitmask_operators<std::ios_base::fmtflags>();
 }
-// { dg-warning "ignoring return value.*operator\\|" "" { target c++17 } 0 }
-// { dg-warning "ignoring return value.*operator&" "" { target c++17 } 0 }
-// { dg-warning "ignoring return value.*operator\\^" "" { target c++17 } 0 }
-// { dg-warning "ignoring return value.*operator~" "" { target c++17 } 0 }
+// { dg-warning "ignoring return value.*operator\\|" "" { target c++11 } 0 }
+// { dg-warning "ignoring return value.*operator&" "" { target c++11 } 0 }
+// { dg-warning "ignoring return value.*operator\\^" "" { target c++11 } 0 }
+// { dg-warning "ignoring return value.*operator~" "" { target c++11 } 0 }
diff --git a/libstdc++-v3/testsuite/27_io/ios_base/types/iostate/bitmask_operators.cc b/libstdc++-v3/testsuite/27_io/ios_base/types/iostate/bitmask_operators.cc
index a984358..d6580bb 100644
--- a/libstdc++-v3/testsuite/27_io/ios_base/types/iostate/bitmask_operators.cc
+++ b/libstdc++-v3/testsuite/27_io/ios_base/types/iostate/bitmask_operators.cc
@@ -27,7 +27,7 @@ int main()
 {
   __gnu_test::bitmask_operators<std::ios_base::iostate>();
 }
-// { dg-warning "ignoring return value.*operator\\|" "" { target c++17 } 0 }
-// { dg-warning "ignoring return value.*operator&" "" { target c++17 } 0 }
-// { dg-warning "ignoring return value.*operator\\^" "" { target c++17 } 0 }
-// { dg-warning "ignoring return value.*operator~" "" { target c++17 } 0 }
+// { dg-warning "ignoring return value.*operator\\|" "" { target c++11 } 0 }
+// { dg-warning "ignoring return value.*operator&" "" { target c++11 } 0 }
+// { dg-warning "ignoring return value.*operator\\^" "" { target c++11 } 0 }
+// { dg-warning "ignoring return value.*operator~" "" { target c++11 } 0 }
diff --git a/libstdc++-v3/testsuite/27_io/ios_base/types/openmode/bitmask_operators.cc b/libstdc++-v3/testsuite/27_io/ios_base/types/openmode/bitmask_operators.cc
index 6d02421..9a94d9b 100644
--- a/libstdc++-v3/testsuite/27_io/ios_base/types/openmode/bitmask_operators.cc
+++ b/libstdc++-v3/testsuite/27_io/ios_base/types/openmode/bitmask_operators.cc
@@ -27,7 +27,7 @@ int main()
 {
   __gnu_test::bitmask_operators<std::ios_base::openmode>();
 }
-// { dg-warning "ignoring return value.*operator\\|" "" { target c++17 } 0 }
-// { dg-warning "ignoring return value.*operator&" "" { target c++17 } 0 }
-// { dg-warning "ignoring return value.*operator\\^" "" { target c++17 } 0 }
-// { dg-warning "ignoring return value.*operator~" "" { target c++17 } 0 }
+// { dg-warning "ignoring return value.*operator\\|" "" { target c++11 } 0 }
+// { dg-warning "ignoring return value.*operator&" "" { target c++11 } 0 }
+// { dg-warning "ignoring return value.*operator\\^" "" { target c++11 } 0 }
+// { dg-warning "ignoring return value.*operator~" "" { target c++11 } 0 }
diff --git a/libstdc++-v3/testsuite/ext/concept_checks.cc b/libstdc++-v3/testsuite/ext/concept_checks.cc
index abb43a4..0166004 100644
--- a/libstdc++-v3/testsuite/ext/concept_checks.cc
+++ b/libstdc++-v3/testsuite/ext/concept_checks.cc
@@ -73,10 +73,10 @@ test2054( )
   upper_bound(Index.begin(), Index.end(), SearchTerm, aComparison);
   equal_range(Index.begin(), Index.end(), SearchTerm, aComparison);
   binary_search(Index.begin(), Index.end(), SearchTerm, aComparison);
-  // { dg-warning "ignoring return value" "" { target c++17 } 72 }
-  // { dg-warning "ignoring return value" "" { target c++17 } 73 }
-  // { dg-warning "ignoring return value" "" { target c++17 } 74 }
-  // { dg-warning "ignoring return value" "" { target c++17 } 75 }
+  // { dg-warning "ignoring return value" "" { target c++11 } 72 }
+  // { dg-warning "ignoring return value" "" { target c++11 } 73 }
+  // { dg-warning "ignoring return value" "" { target c++11 } 74 }
+  // { dg-warning "ignoring return value" "" { target c++11 } 75 }
 }
 
 int main()
diff --git a/libstdc++-v3/testsuite/ext/is_heap/47709.cc b/libstdc++-v3/testsuite/ext/is_heap/47709.cc
index 50bbcca..64966d6 100644
--- a/libstdc++-v3/testsuite/ext/is_heap/47709.cc
+++ b/libstdc++-v3/testsuite/ext/is_heap/47709.cc
@@ -24,6 +24,5 @@
 void foo()
 {
   std::vector<int> v;
-  is_heap(v.begin(), v.end());
-  // { dg-warning "ignoring return value" "" { target c++17 } 27 }
+  is_heap(v.begin(), v.end()); // { dg-warning "ignoring return value" }
 }
diff --git a/libstdc++-v3/testsuite/ext/is_sorted/cxx0x.cc b/libstdc++-v3/testsuite/ext/is_sorted/cxx0x.cc
index 3592d68..3167248 100644
--- a/libstdc++-v3/testsuite/ext/is_sorted/cxx0x.cc
+++ b/libstdc++-v3/testsuite/ext/is_sorted/cxx0x.cc
@@ -23,6 +23,5 @@
 void foo()
 {
   std::vector<int> v;
-  is_sorted(v.begin(), v.end());
-  // { dg-warning "ignoring return value" "" { target c++17 } 26 }
+  is_sorted(v.begin(), v.end()); // { dg-warning "ignoring return value" }
 }