The array that stores the dynamic extents used to be default
initialized. The standard requires value intialization. This
commit fixes the bug and adds a test.
libstdc++-v3/ChangeLog:
* include/std/mdspan: Value initialize the array storing the
dynamic extents.
* testsuite/23_containers/mdspan/extents/ctor_default.cc: New
test.
Signed-off-by: Luc Grosheintz <luc.groshei...@gmail.com>
---
libstdc++-v3/include/std/mdspan | 2 +-
.../mdspan/extents/ctor_default.cc | 41 +++++++++++++++++++
2 files changed, 42 insertions(+), 1 deletion(-)
create mode 100644
libstdc++-v3/testsuite/23_containers/mdspan/extents/ctor_default.cc
diff --git a/libstdc++-v3/include/std/mdspan b/libstdc++-v3/include/std/mdspan
index 47cfa405e44..bcf2fa60fea 100644
--- a/libstdc++-v3/include/std/mdspan
+++ b/libstdc++-v3/include/std/mdspan
@@ -146,7 +146,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
private:
using _S_storage = __array_traits<_IndexType, _S_rank_dynamic>::_Type;
- [[no_unique_address]] _S_storage _M_dynamic_extents;
+ [[no_unique_address]] _S_storage _M_dynamic_extents{};
};
template<typename _OIndexType, typename _SIndexType>
diff --git
a/libstdc++-v3/testsuite/23_containers/mdspan/extents/ctor_default.cc
b/libstdc++-v3/testsuite/23_containers/mdspan/extents/ctor_default.cc
new file mode 100644
index 00000000000..eec300f6896
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/mdspan/extents/ctor_default.cc
@@ -0,0 +1,41 @@
+// { dg-do run { target c++23 } }
+#include <mdspan>
+
+#include <cstdint>
+#include <testsuite_hooks.h>
+
+constexpr auto dyn = std::dynamic_extent;
+
+template<typename Extents>
+ constexpr void
+ test_default_ctor()
+ {
+ Extents exts;
+ for(size_t i = 0; i < Extents::rank(); ++i)
+ if(exts.static_extent(i) == std::dynamic_extent)
+ VERIFY(exts.extent(i) == 0);
+ else
+ VERIFY(exts.extent(i) == Extents::static_extent(i));
+ }
+
+constexpr bool
+test_default_ctor_all()
+{
+ test_default_ctor<std::extents<int, 1>>();
+ test_default_ctor<std::extents<int, dyn>>();
+ test_default_ctor<std::extents<int, 1, 2>>();
+ test_default_ctor<std::extents<int, dyn, 2>>();
+ test_default_ctor<std::extents<int, dyn, dyn>>();
+ test_default_ctor<std::extents<int, 1, 2, 3>>();
+ test_default_ctor<std::extents<int, dyn, 2, dyn>>();
+ test_default_ctor<std::extents<int, dyn, dyn, dyn>>();
+ return true;
+}
+
+int
+main()
+{
+ test_default_ctor_all();
+ static_assert(test_default_ctor_all());
+ return 0;
+}
--
2.49.0
