[PATCH] PR libstdc++/80762 avoid ambiguous __constructible_from<void, void>

[Christophe Lyon]

On Wed, 12 Dec 2018 at 17:13, Jonathan Wakely <jwakely@redhat.com> wrote:
>
> Ensure we don't try to instantiate __is_constructible_from<void, void>,
> because there are two partial specializations that are equally good
> matches.
>
>         PR libstdc++/80762
>         * include/bits/fs_path.h (path::_Path): Use remove_cv_t and is_void.
>         * include/experimental/bits/fs_path.h (path::_Path): Likewise.
>         * testsuite/27_io/filesystem/path/construct/80762.cc: New test.
>         * testsuite/experimental/filesystem/path/construct/80762.cc: New test.
>

Hi Jonathan,

One of the new tests fails on bare-metal/newlib targets (aarch64-elf/arm-eabi):
FAIL: experimental/filesystem/path/construct/80762.cc (test for excess errors)
/libstdc++-v3/testsuite/experimental/filesystem/path/construct/80762.cc:20:
fatal error: experimental/filesystem: No such file or directory

I think there was a similar issue recently, but I don't remember how
you fixed it?

Thanks


> Tested x86_64-linux (and manually verified it fixes the clang errors).
>
> Committed to trunk. This is worth backporting too, I think.
>