C++17 P0522R0 (Matching template template parameters to compatible arguments) only partially implemented

[ackelcn]

I encounter a commit that repaired a clang bug. This commit is from WEB++:
the-moisrex/webpp@97a5947

 - typename istl::filter_parameters<istl::templated_negation<stl::is_void>::type,
 +typename istl::filter_parameters<istl::templated_negation<stl::is_void>::template type,
                                   typename details::resource_extractor_impl<AllocDescTypes>::type>::type

Looks like a clang bug?

[the-moisrex]

This bug is known and described here.

[llvmbot]

@llvm/issue-subscribers-clang-frontend

[llvmbot]

@llvm/issue-subscribers-c-20

[fhahn]

@the-moisrex thanks, I updated the title with the info you provided.

[mizvekov]

I worked on an implementation of this some time ago.
See: https://reviews.llvm.org/D109496

We tried first just implementing the wording as is, without any resolution to the new issues. There was negative push back, so we reverted. I implemented a workaround, but then @zygoloid suggested a better approach, but I did not have the time to follow that up yet.

[ackelcn]

@mizvekov Many thanks for your effort.
@the-moisrex provided a code sample, and explained how to reproduce the bug. Hope that this problem can be fully resolved.

the-moisrex/webpp#132

[pinskia]

Cross reference to GCC bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114841 .