Tested x86_64-linux. Pushed to trunk.
-- >8--
This test fails if chrono::days::rep or chrono::years::rep is a 32-bit
type, because a large days or years value silently overflows a 32-bit
integer when converted to seconds. It would be conforming to implement
chrono::days as chrono::duration<int32_t, ratio<86400>>, but would make
this overflow case more likely. Similarly for chrono::years,
chrono::months and chrono::weeks. This test is here to remind us not to
make that change lightly.
libstdc++-v3/ChangeLog:
* testsuite/20_util/duration/arithmetic/overflow_c++20.cc: New
test.
---
.../duration/arithmetic/overflow_c++20.cc | 29 +++++++++++++++++++
1 file changed, 29 insertions(+)
create mode 100644
libstdc++-v3/testsuite/20_util/duration/arithmetic/overflow_c++20.cc
diff --git
a/libstdc++-v3/testsuite/20_util/duration/arithmetic/overflow_c++20.cc
b/libstdc++-v3/testsuite/20_util/duration/arithmetic/overflow_c++20.cc
new file mode 100644
index 00000000000..42fa7ea55fb
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/duration/arithmetic/overflow_c++20.cc
@@ -0,0 +1,29 @@
+// { dg-options "-std=gnu++20" }
+// { dg-do run { target c++20 } }
+
+#include <chrono>
+#include <cstdint>
+#include <testsuite_hooks.h>
+
+void
+test_overflow()
+{
+ using namespace std::chrono;
+
+ using seconds32_t = duration<std::int_least32_t>;
+ seconds32_t t = 14h + 25min + 55s;
+ auto snow = sys_days(1854y/December/11);
+ auto snow_t = snow + t;
+ // Fails if days::rep is 32-bit:
+ VERIFY( snow_t.time_since_epoch() < seconds::zero() );
+ auto y = floor<years>(snow);
+ auto y_t = y + t;
+ // Fails if years::rep is 32-bit:
+ VERIFY( y_t.time_since_epoch() < seconds::zero() );
+ VERIFY( y_t < snow_t );
+}
+
+int main()
+{
+ test_overflow();
+}
--
2.38.1
