On 02/08/18 22:16 +0200, François Dumont wrote:
Hi
Here is a patch to avoid definition of invalid operators on the
Debug mode safe iterator type depending on its category.
Even if it is limited to the Debug mode code I would like to have
a feedback before committing. Especially on the following points:
- _Safe_tagged_iterator: Is the name ok ?
Hmm, maybe "strict" instead of tagged?
But do we need a new name? Can we just change _Safe_iterator instead
of adding a new type?
Where is _Safe_iterator still used? Just local iterators in unordered
containers? Is it OK to remove most of the functions that used to
support it? (__niter_base etc).
Could we add a new type for the local iterators, and just change
_Safe_iterator directly so it doesn't expose unsupported operations?
That would make the patch *much* smaller, as you wouldn't need to
change all the uses of _Safe_iterator.
Another approach would be to use mixins to expose the operations:
template<typename _Iter, typename _Cat>
struct _Safe_iterator_mixin<_Iter, _Cat>
{
typename iterator_traits<_Iter>::reference
operator*()
{ return static_cast<_Iter*>(this)->_M_deref(); }
};
template<typename _Iter, typename _Cat>
struct _Safe_iterator_mixin<_Iter, forward_iterator_tag>
{
_Iter& operator++()
{ return static_cast<_Iter*>(this)->_M_preinc(); }
_Iter operator++(int)
{ return static_cast<_Iter*>(this)->_M_postinc(); }
};
template<typename _Iter, typename _Cat>
struct _Safe_iterator_mixin<_Iter, bidirectional_iterator_tag>
{
_Iter& operator--()
{ return static_cast<_Iter*>(this)->_M_predec(); }
_Iter operator--(int)
{ return static_cast<_Iter*>(this)->_M_postdec(); }
};
etc.
then in _Safe_iterator rename the operator functions, so operator*
becomes _M_deref, operator++ becomes _M_preinc etc. and then derive
from _Safe_iterator_mixin which declares the operators.
- Inheritance between the different _Safe_tagged_iterator
instantiations. I am already working on making the operators friends
as we discuss in another thread so I might review this design at this
moment.
- Are concept checks I added to testsuite_containers.h citerator ok ?
Yes, they look useful.
This patch also does some cleanup on Debug functions.
__check_dereferenceable was not used (anymore maybe) so I removed it.
It would have made the patch a bit more manageable to keep that as a
separate patch, but nevermind.
diff --git a/libstdc++-v3/include/debug/deque b/libstdc++-v3/include/debug/deque
index 93b82cf..213e23b 100644
--- a/libstdc++-v3/include/debug/deque
+++ b/libstdc++-v3/include/debug/deque
@@ -57,12 +57,14 @@ namespace __debug
typedef __gnu_debug::_Equal_to<_Base_const_iterator> _Equal;
public:
+ typedef _Base normal_type;
normal_type is not a reserved name, so can't be used.
diff --git a/libstdc++-v3/include/debug/stl_iterator.h
b/libstdc++-v3/include/debug/stl_iterator.h
index f20b000..fd20160 100644
--- a/libstdc++-v3/include/debug/stl_iterator.h
+++ b/libstdc++-v3/include/debug/stl_iterator.h
@@ -75,12 +76,6 @@ namespace __gnu_debug
#else
template<typename _Iterator>
inline auto
- __base(const std::reverse_iterator<_Iterator>& __it)
- -> decltype(std::__make_reverse_iterator(__base(__it.base())))
- { return std::__make_reverse_iterator(__base(__it.base())); }
This removal doesn't seem to be mentioned in the ChangeLog:
* include/debug/stl_iterator.h
(__is_safe_random_iterator<std::reverse_iterator<>>): Remove.
(__base(const std::reverse_iterator<_Safe_tagged_iterator<_It, _Sq,
std::random_access_iterator_tag>)): New overload.
