[PATCH 04/13] libstdc++: Replace dg-options "-std=c++20" with dg-add-options strict_std

[Jonathan Wakely via Gcc-patches]

The testsuite will automatically select C++20 for these tests now, and
removing the hardcoded -std option allows them to be tested for C++23
and C++26 as well. Because they test a problem seen with -std=c++20 add
the new { dg-add-options strict_std } directive so that the test runner
uses -std=c++NN not -std=gnu++NN.

libstdc++-v3/ChangeLog:

        * testsuite/24_iterators/reverse_iterator/100639.cc: Remove
        dg-options and add dg-add-options strict_std.
        * testsuite/std/ranges/iota/93267.cc: Likewise.
        * testsuite/std/ranges/iota/96042.cc: Likewise.
        * testsuite/std/ranges/iota/size.cc: Likewise.
        * testsuite/std/ranges/subrange/96042.cc: Likewise.
---
 .../testsuite/24_iterators/reverse_iterator/100639.cc         | 4 ++--
 libstdc++-v3/testsuite/std/ranges/iota/93267.cc               | 4 ++--
 libstdc++-v3/testsuite/std/ranges/iota/96042.cc               | 4 ++--
 libstdc++-v3/testsuite/std/ranges/iota/size.cc                | 2 +-
 libstdc++-v3/testsuite/std/ranges/subrange/96042.cc           | 4 ++--
 5 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/libstdc++-v3/testsuite/24_iterators/reverse_iterator/100639.cc 
b/libstdc++-v3/testsuite/24_iterators/reverse_iterator/100639.cc
index 5d0a7f4af27..68bf4e08488 100644
--- a/libstdc++-v3/testsuite/24_iterators/reverse_iterator/100639.cc
+++ b/libstdc++-v3/testsuite/24_iterators/reverse_iterator/100639.cc
@@ -15,8 +15,8 @@
 // with this library; see the file COPYING3.  If not see
 // <http://www.gnu.org/licenses/>.
 
-// { dg-options "-std=c++2a" }
-// { dg-do compile { target c++2a } }
+// { dg-do compile { target c++20 } }
+// { dg-add-options strict_std }
 
 // PR libstdc++/100639
 
diff --git a/libstdc++-v3/testsuite/std/ranges/iota/93267.cc 
b/libstdc++-v3/testsuite/std/ranges/iota/93267.cc
index 3bb74bbf485..4306aea4d43 100644
--- a/libstdc++-v3/testsuite/std/ranges/iota/93267.cc
+++ b/libstdc++-v3/testsuite/std/ranges/iota/93267.cc
@@ -15,8 +15,8 @@
 // with this library; see the file COPYING3.  If not see
 // <http://www.gnu.org/licenses/>.
 
-// { dg-options "-std=c++2a" }
-// { dg-do compile { target c++2a } }
+// { dg-do compile { target c++20 } }
+// { dg-add-options strict_std }
 
 #include <ranges>
 
diff --git a/libstdc++-v3/testsuite/std/ranges/iota/96042.cc 
b/libstdc++-v3/testsuite/std/ranges/iota/96042.cc
index 7070a7d6b10..6c553de9ce9 100644
--- a/libstdc++-v3/testsuite/std/ranges/iota/96042.cc
+++ b/libstdc++-v3/testsuite/std/ranges/iota/96042.cc
@@ -15,8 +15,8 @@
 // with this library; see the file COPYING3.  If not see
 // <http://www.gnu.org/licenses/>.
 
-// { dg-options "-std=c++2a" }
-// { dg-do compile { target c++2a } }
+// { dg-do compile { target c++20 } }
+// { dg-add-options strict_std }
 
 #include <ranges>
 #include <limits>
diff --git a/libstdc++-v3/testsuite/std/ranges/iota/size.cc 
b/libstdc++-v3/testsuite/std/ranges/iota/size.cc
index 958cb5f03c8..28848d55561 100644
--- a/libstdc++-v3/testsuite/std/ranges/iota/size.cc
+++ b/libstdc++-v3/testsuite/std/ranges/iota/size.cc
@@ -15,8 +15,8 @@
 // with this library; see the file COPYING3.  If not see
 // <http://www.gnu.org/licenses/>.
 
-// { dg-options "-std=c++2a" }
 // { dg-do compile { target c++2a } }
+// { dg-add-options strict_std }
 
 #include <ranges>
 #include <limits>
diff --git a/libstdc++-v3/testsuite/std/ranges/subrange/96042.cc 
b/libstdc++-v3/testsuite/std/ranges/subrange/96042.cc
index bc22f999ed8..3856952eeb3 100644
--- a/libstdc++-v3/testsuite/std/ranges/subrange/96042.cc
+++ b/libstdc++-v3/testsuite/std/ranges/subrange/96042.cc
@@ -15,8 +15,8 @@
 // with this library; see the file COPYING3.  If not see
 // <http://www.gnu.org/licenses/>.
 
-// { dg-options "-std=c++20" }
-// { dg-do compile { target c++2a } }
+// { dg-do compile { target c++20 } }
+// { dg-add-options strict_std }
 
 #include <ranges>
 #include <limits>
-- 
2.41.0