On Tue, 15 Jun 2021 at 19:28, Jonathan Wakely wrote:
>
> By changing __cust_access::__decay_copy from a function template to a
> function object we avoid ADL. That means it's fine to call it
> unqualified (the compiler won't waste time doing ADL in associated
> namespaces, and won't try to complete associated types).
>
> This also makes some other minor simplications to other concepts for the
> [range.access] CPOs.
>
> Signed-off-by: Jonathan Wakely <jwak...@redhat.com>
>
> libstdc++-v3/ChangeLog:
>
> * include/bits/iterator_concepts.h (__cust_access::__decay_copy):
> Replace with function object.
> (__cust_access::__member_begin, ___cust_access::_adl_begin): Use
> __decay_copy unqualified.
> * include/bits/ranges_base.h (__member_end, __adl_end):
> Likewise. Use __range_iter_t for type of ranges::begin.
> (__member_rend): Use correct value category for rbegin argument.
> (__member_data): Use __decay_copy unqualified.
> (__begin_data): Use __range_iter_t for type of ranges::begin.
That change makes it impossible to import the header in a module.
Fixed by this patch.
Tested powerpc64le-linux. Pushed to trunk.
commit c25e3bf87975280a603ff18fba387c6707ce4a95
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Wed Jun 16 12:47:32 2021
libstdc++: Use named struct for __decay_copy
In r12-1486-gcb326a6442f09cb36b05ce556fc91e10bfeb0cf6 I changed
__decay_copy to be a function object of unnamed class type. This causes
problems when importing the library headers:
error: conflicting global module declaration 'constexpr const
std::ranges::__cust_access::<unnamed struct>
std::ranges::__cust_access::__decay_copy'
The fix is to use a named struct instead of an anonymous one.
Signed-off-by: Jonathan Wakely <jwak...@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/iterator_concepts.h (__decay_copy): Name type.
diff --git a/libstdc++-v3/include/bits/iterator_concepts.h
b/libstdc++-v3/include/bits/iterator_concepts.h
index d18ae32bf20..11748e5ed7b 100644
--- a/libstdc++-v3/include/bits/iterator_concepts.h
+++ b/libstdc++-v3/include/bits/iterator_concepts.h
@@ -930,7 +930,8 @@ namespace ranges
{
using std::__detail::__class_or_enum;
- struct {
+ struct _Decay_copy final
+ {
template<typename _Tp>
constexpr decay_t<_Tp>
operator()(_Tp&& __t) const
