On 24/02/20 08:29 -0500, Patrick Palka wrote:
This adds some missing pieces of the Ranges TS that make back_insert_iterator
and
front_insert_iterator conform to the new output_iterator requirements.
It also fixes a bug in ranges::__copy_or_move and
ranges::__copy_or_move_backward in which we were inspecting the iter_value_t of
the output iterator, but iterators such as back_insert_iterator and
front_insert_iterator whose value_type is defined to be void do not have an
iter_value_t according to [readable.traits] p4. The entire __use_memmove
condition can probably be refactored, but the simplest fix for now is to inspect
the iterator_traits of the output iterator instead.
libstdc++-v3/ChangeLog:
PR libstdc++/93884
* include/bits/ranges_algobase.h (__copy_or_move,
__copy_or_move_backward): Don't inspect the iter_value_t of the output
iterator, instead inspect its iterator_traits directly.
* include/bits/stl_iterator.h (back_insert_iterator::container):
Conditionally initialize.
(back_insert_iterator::difference_type): Conditionally define.
(back_insert_iterator::back_insert_iterator): Conditionally define this
default constructor.
(front_insert_iterator::container): Conditionally initialize.
(front_insert_iterator::difference_type): Conditionally define.
(front_insert_iterator::front_insert_iterator): Conditionally define
this default constructor.
---
libstdc++-v3/include/bits/ranges_algobase.h | 4 +-
libstdc++-v3/include/bits/stl_iterator.h | 22 ++++++++++
.../back_insert_iterator/pr93884.C | 44 +++++++++++++++++++
.../front_insert_iterator/pr93884.C | 44 +++++++++++++++++++
4 files changed, 112 insertions(+), 2 deletions(-)
create mode 100644
libstdc++-v3/testsuite/24_iterators/back_insert_iterator/pr93884.C
create mode 100644
libstdc++-v3/testsuite/24_iterators/front_insert_iterator/pr93884.C
diff --git a/libstdc++-v3/include/bits/ranges_algobase.h
b/libstdc++-v3/include/bits/ranges_algobase.h
index 807822e99c8..739424e1a2d 100644
--- a/libstdc++-v3/include/bits/ranges_algobase.h
+++ b/libstdc++-v3/include/bits/ranges_algobase.h
@@ -249,7 +249,7 @@ namespace ranges
else if constexpr (sized_sentinel_for<_Sent, _Iter>)
{
using _ValueTypeI = iter_value_t<_Iter>;
- using _ValueTypeO = iter_value_t<_Out>;
+ using _ValueTypeO = iterator_traits<_Out>::value_type;
I think this will fail to compile with Clang, because it needs
'typename' there.
constexpr bool __use_memmove
= (is_trivially_copyable_v<_ValueTypeI>
&& is_same_v<_ValueTypeI, _ValueTypeO>
@@ -386,7 +386,7 @@ namespace ranges
else if constexpr (sized_sentinel_for<_Sent, _Iter>)
{
using _ValueTypeI = iter_value_t<_Iter>;
- using _ValueTypeO = iter_value_t<_Out>;
+ using _ValueTypeO = iterator_traits<_Out>::value_type;
Same here.
