Here is the _Safe_iterator one.
Doing so I noticed that pointer_traits rebind for __normal_iterator was
wrong and added tests on it.
For _Safe_iterator maybe I should specialize only when instantiated with
__normal_iterator ? Or maybe limit to random_access_iterator_tag ?
Whatever the pointer_to implementation is problematic, we can only
produce singular iterator as I did ifor now.
François
On 28/09/21 9:25 pm, Jonathan Wakely via Libstdc++ wrote:
This allows std::__to_address to be used with __normal_iterator in
C++11/14/17 modes. Without the partial specialization the deduced
pointer_traits::element_type is incorrect, and so the return type of
__to_address is wrong.
A similar partial specialization is probably needed for
__gnu_debug::_Safe_iterator.
Signed-off-by: Jonathan Wakely <jwak...@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/stl_iterator.h (pointer_traits): Define partial
specialization for __normal_iterator.
* testsuite/24_iterators/normal_iterator/to_address.cc: New test.
Tested x86_64-linux. Committed to trunk.
diff --git a/libstdc++-v3/include/bits/stl_iterator.h
b/libstdc++-v3/include/bits/stl_iterator.h
index 004d767224d..f7e851718c1 100644
--- a/libstdc++-v3/include/bits/stl_iterator.h
+++ b/libstdc++-v3/include/bits/stl_iterator.h
@@ -1294,13 +1294,17 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
private:
using _Base = pointer_traits<_Iterator>;
+ template<typename _Tp>
+ using __base_rebind = typename _Base::template rebind<_Tp>;
+
public:
using element_type = typename _Base::element_type;
using pointer = __gnu_cxx::__normal_iterator<_Iterator, _Container>;
using difference_type = typename _Base::difference_type;
template<typename _Tp>
- using rebind = __gnu_cxx::__normal_iterator<_Tp, _Container>;
+ using rebind =
+ __gnu_cxx::__normal_iterator<__base_rebind<_Tp>, _Container>;
static pointer
pointer_to(element_type& __e) noexcept
diff --git a/libstdc++-v3/include/debug/safe_iterator.h
b/libstdc++-v3/include/debug/safe_iterator.h
index 5584d06de5a..5461d2b342f 100644
--- a/libstdc++-v3/include/debug/safe_iterator.h
+++ b/libstdc++-v3/include/debug/safe_iterator.h
@@ -1013,6 +1013,44 @@ namespace __gnu_debug
} // namespace __gnu_debug
+#if __cplusplus >= 201103L
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+ template<typename _Iterator, typename _Sequence, typename _Category>
+ struct pointer_traits<__gnu_debug::_Safe_iterator<_Iterator, _Sequence,
+ _Category>>
+ {
+ private:
+ using _Base = pointer_traits<_Iterator>;
+
+ template<typename _Tp>
+ using __base_rebind = typename _Base::template rebind<_Tp>;
+
+ public:
+ using element_type = typename _Base::element_type;
+ using pointer =
+ __gnu_debug::_Safe_iterator<_Iterator, _Sequence, _Category>;
+ using difference_type = typename _Base::difference_type;
+
+ template<typename _Tp>
+ using rebind =
+ __gnu_debug::_Safe_iterator<__base_rebind<_Tp>, _Sequence, _Category>;
+
+ static pointer
+ pointer_to(element_type& __e) noexcept
+ { return pointer(_Base::pointer_to(__e), nullptr); }
+
+#if __cplusplus >= 202002L
+ static element_type*
+ to_address(pointer __p) noexcept
+ { return __p.base(); }
+#endif
+ };
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace
+#endif
+
#undef _GLIBCXX_DEBUG_VERIFY_DIST_OPERANDS
#undef _GLIBCXX_DEBUG_VERIFY_REL_OPERANDS
#undef _GLIBCXX_DEBUG_VERIFY_EQ_OPERANDS
diff --git a/libstdc++-v3/testsuite/20_util/pointer_traits/rebind.cc
b/libstdc++-v3/testsuite/20_util/pointer_traits/rebind.cc
index 159ea8f5294..b78e974d777 100644
--- a/libstdc++-v3/testsuite/20_util/pointer_traits/rebind.cc
+++ b/libstdc++-v3/testsuite/20_util/pointer_traits/rebind.cc
@@ -18,6 +18,7 @@
// { dg-do compile { target c++11 } }
#include <memory>
+#include <vector>
using std::is_same;
@@ -66,3 +67,13 @@ template<typename T, int = 0>
};
// PR libstdc++/72793 specialization of pointer_traits is still well-formed:
std::pointer_traits<CannotRebind<int>>::element_type e;
+
+static_assert(is_same<typename std::pointer_traits<
+ Rebind<typename std::vector<int>::iterator, long>>::element_type,
+ long>::value,
+ "iterator rebind");
+
+static_assert(is_same<typename std::pointer_traits<
+ Rebind<typename std::vector<int>::const_iterator,
long>>::element_type,
+ long>::value,
+ "const_iterator rebind");
diff --git a/libstdc++-v3/testsuite/24_iterators/normal_iterator/to_address.cc
b/libstdc++-v3/testsuite/24_iterators/normal_iterator/to_address.cc
index 510d627435f..433c803beb1 100644
--- a/libstdc++-v3/testsuite/24_iterators/normal_iterator/to_address.cc
+++ b/libstdc++-v3/testsuite/24_iterators/normal_iterator/to_address.cc
@@ -1,6 +1,9 @@
// { dg-do compile { target { c++11 } } }
#include <string>
+#include <vector>
#include <memory>
char* p = std::__to_address(std::string("1").begin());
const char* q = std::__to_address(std::string("2").cbegin());
+int* r = std::__to_address(std::vector<int>(1, 1).begin());
+const int* s = std::__to_address(std::vector<int>(1, 1).cbegin());
