The std::uninitialized_{value,default}_construct{,_n} algorithms should
be able to create arrays, but that currently fails because when an
exception happens they clean up using std::_Destroy and in C++17 that
doesn't support destroying arrays. (For C++20 and later, std::destroy
does handle destroying arrays.)
This commit adjusts the _UninitDestroyGuard RAII type used by those
algos so that in C++17 mode it recursively destroys each rank of an
array type, only using std::_Destroy for the last rank when it's
destroying non-array objects.
libstdc++-v3/ChangeLog:
PR libstdc++/120397
* include/bits/stl_uninitialized.h (_UninitDestroyGuard<I,void>):
Add new member function _S_destroy and call it from the
destructor.
*
testsuite/20_util/specialized_algorithms/uninitialized_default_construct/120397.cc:
New test.
*
testsuite/20_util/specialized_algorithms/uninitialized_value_construct/120397.cc:
New test.
---
Tested x86_64-linux.
libstdc++-v3/include/bits/stl_uninitialized.h | 19 ++++++++++++++++++-
.../uninitialized_default_construct/120397.cc | 19 +++++++++++++++++++
.../uninitialized_value_construct/120397.cc | 19 +++++++++++++++++++
3 files changed, 56 insertions(+), 1 deletion(-)
create mode 100644
libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_default_construct/120397.cc
create mode 100644
libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_value_construct/120397.cc
diff --git a/libstdc++-v3/include/bits/stl_uninitialized.h
b/libstdc++-v3/include/bits/stl_uninitialized.h
index 9372e5a01847..19d784bed4fc 100644
--- a/libstdc++-v3/include/bits/stl_uninitialized.h
+++ b/libstdc++-v3/include/bits/stl_uninitialized.h
@@ -117,7 +117,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
~_UninitDestroyGuard()
{
if (__builtin_expect(_M_cur != 0, 0))
- std::_Destroy(_M_first, *_M_cur);
+ _S_destroy(_M_first, *_M_cur);
}
_GLIBCXX20_CONSTEXPR
@@ -128,6 +128,23 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
private:
_UninitDestroyGuard(const _UninitDestroyGuard&);
+
+ template<typename _Iter>
+ _GLIBCXX20_CONSTEXPR
+ static void
+ _S_destroy(_Iter __first, _Iter __last)
+ {
+#if __cplusplus == 201703L
+ // std::uninitialized_{value,default}{,_n} can construct array types,
+ // but std::_Destroy cannot handle them until C++20 (PR 120397).
+ using _ValT = typename iterator_traits<_Iter>::value_type;
+ if constexpr (is_array<_ValT>::value)
+ for (; __first != __last; ++__first)
+ _S_destroy(*__first, *__first + extent<_ValT>::value);
+ else
+#endif
+ std::_Destroy(__first, __last);
+ }
};
// This is the default implementation of std::uninitialized_copy.
diff --git
a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_default_construct/120397.cc
b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_default_construct/120397.cc
new file mode 100644
index 000000000000..7aa05d7d12f4
--- /dev/null
+++
b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_default_construct/120397.cc
@@ -0,0 +1,19 @@
+// { dg-do compile { target c++17 } }
+
+#include <memory>
+
+// PR libstdc++/120397
+// std::uninitialized_value_construct cannot create arrays of non-trivially
+// destructible types
+
+struct X { X() { } ~X() { } };
+
+void def(X (*x)[1])
+{
+ std::uninitialized_default_construct(x, x+1);
+}
+
+void def_n(X (*x)[1])
+{
+ std::uninitialized_default_construct_n(x, 1);
+}
diff --git
a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_value_construct/120397.cc
b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_value_construct/120397.cc
new file mode 100644
index 000000000000..f4d9fce20213
--- /dev/null
+++
b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_value_construct/120397.cc
@@ -0,0 +1,19 @@
+// { dg-do compile { target c++17 } }
+
+#include <memory>
+
+// PR libstdc++/120397
+// std::uninitialized_value_construct cannot create arrays of non-trivially
+// destructible types
+
+struct X { X() { } ~X() { } };
+
+void val(X (*x)[1])
+{
+ std::uninitialized_value_construct(x, x+1);
+}
+
+void val_n(X (*x)[1])
+{
+ std::uninitialized_value_construct_n(x, 1);
+}
--
2.49.0
