[Bug c++/121705] [16 Regression] When using import std, formatting std::chrono::year_month_day will cause compilation failure

[ppalka at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121705

Patrick Palka <ppalka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ppalka at gcc dot gnu.org

--- Comment #6 from Patrick Palka <ppalka at gcc dot gnu.org> ---
We can work around it declaring __parts with its known non-dependent type to
avoid ADL:

diff --git a/libstdc++-v3/include/bits/chrono_io.h
b/libstdc++-v3/include/bits/chrono_io.h
index 809d795cbf2b..cfabbb32c6a2 100644
--- a/libstdc++-v3/include/bits/chrono_io.h
+++ b/libstdc++-v3/include/bits/chrono_io.h
@@ -2637,7 +2637,7 @@ namespace __format
               basic_format_context<_Out, _CharT>& __fc) const
        {
          __format::_ChronoData<_CharT> __cd{};
-         auto __parts = _M_f._M_spec._M_needed;
+         __format::_ChronoParts __parts = _M_f._M_spec._M_needed;
          __parts = __cd._M_fill_year_month(__t, __parts);
          __parts = __cd._M_fill_day(__t.day(), __parts);
          if (__parts == 0)