On Sun, 2 Nov 2025, Jason Merrill wrote:
> Tested x86_64-pc-linux-gnu, OK for trunk?
>
> -- 8< --
>
> Since the implementation namespaces __detail and __exception_ptr aren't
> exported from std, ADL can't find these functions there. Adding friend
> declarations makes it work.
I thought Nathaniel's module ADL fixes (for 121705 and/or 117658) would
make this unnecessary?
>
> libstdc++-v3/ChangeLog:
>
> * include/bits/quoted_string.h: Add ADL friends.
> * libsupc++/exception_ptr.h: Add ADL friend.
> ---
> libstdc++-v3/include/bits/quoted_string.h | 23 +++++++++++++++++++++++
> libstdc++-v3/libsupc++/exception_ptr.h | 4 ++++
> 2 files changed, 27 insertions(+)
>
> diff --git a/libstdc++-v3/include/bits/quoted_string.h
> b/libstdc++-v3/include/bits/quoted_string.h
> index 3a828d5eab9..9a51aa367fe 100644
> --- a/libstdc++-v3/include/bits/quoted_string.h
> +++ b/libstdc++-v3/include/bits/quoted_string.h
> @@ -61,6 +61,23 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> _Quoted_string&
> operator=(_Quoted_string&) = delete;
>
> + // Friends for ADL with module std.
> + template<typename _CharT2, typename _Traits>
> + friend std::basic_ostream<_CharT2, _Traits>&
> + operator<<(std::basic_ostream<_CharT2, _Traits>& __os,
> + const _Quoted_string<const _CharT2*, _CharT2>& __str);
> +
> + template<typename _CharT2, typename _Traits, typename _String2>
> + friend std::basic_ostream<_CharT2, _Traits>&
> + operator<<(std::basic_ostream<_CharT2, _Traits>& __os,
> + const _Quoted_string<_String2, _CharT2>& __str);
> +
> + template<typename _CharT2, typename _Traits, typename _Alloc>
> + friend std::basic_istream<_CharT2, _Traits>&
> + operator>>(std::basic_istream<_CharT2, _Traits>& __is,
> + const _Quoted_string<basic_string<_CharT2, _Traits, _Alloc>&,
> + _CharT2>& __str);
> +
> _String _M_string;
> _CharT _M_delim;
> _CharT _M_escape;
> @@ -78,6 +95,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> _Quoted_string&
> operator=(_Quoted_string&) = delete;
>
> + // Friend for ADL with module std.
> + template<typename _CharT2, typename _Traits2, typename _String2>
> + friend std::basic_ostream<_CharT2, _Traits2>&
> + operator<<(std::basic_ostream<_CharT2, _Traits2>& __os,
> + const _Quoted_string<_String2, _CharT2>& __str);
> +
> basic_string_view<_CharT, _Traits> _M_string;
> _CharT _M_delim;
> _CharT _M_escape;
> diff --git a/libstdc++-v3/libsupc++/exception_ptr.h
> b/libstdc++-v3/libsupc++/exception_ptr.h
> index f673a334333..76482db3756 100644
> --- a/libstdc++-v3/libsupc++/exception_ptr.h
> +++ b/libstdc++-v3/libsupc++/exception_ptr.h
> @@ -214,6 +214,10 @@ namespace std _GLIBCXX_VISIBILITY(default)
> { return __x._M_exception_object != __y._M_exception_object; }
> #endif
>
> + // Friend for ADL with module std.
> + friend _GLIBCXX26_CONSTEXPR void
> + swap(exception_ptr& __lhs, exception_ptr& __rhs);
> +
> const class std::type_info*
> __cxa_exception_type() const _GLIBCXX_USE_NOEXCEPT
> __attribute__ ((__pure__));
>
> base-commit: 2be505ace7e5e29a29ab53025762cf1a100a6d76
> --
> 2.51.0
>
>
