Re: [libcxx22] fallout

Rafael Sadowski writes: > On Fri Aug 21, 2026 at 02:15:34PM +0200, Theo Buehler wrote: >> There are basically two main classes of failures: comparison operators >> and locale things and a few odd ones like fish/v3 and >> >> audio/ncmpcpp >> /usr/include/c++/v1/__algorithm/sift_down.h:49:39: error: no matching function for call to object of type 'LocaleBasedSorting' >> 49 | } else if ((__child + 1) < __len && __comp(__first[__child], __first[__child + 1])) { >> | ^~~~~~ >> > > The lambdas are more or less a workaround from me. > > I think, the much cleaner fix would be to teach LocaleBasedSorting to > handle all this, but that means digging even depper into the Boost > lib. I don't want go this way. Anyone? I will take a look at this tomorrow with some fresh eyes. I posted about my investigation here with a crude hack to sift_down.h to revert it to be more like 19.1.7. The original poster used stable_sort. I was curious why [] didn't work but it was happy with pointer arithmetic. Is it boost::iterators::transform_iterator or LocaleBasedSorting that can't deal with []? I see your comment notes that template argument deduction broke. https://github.com/ncmpcpp/ncmpcpp/issues/663#issuecomment-5436536200 > > diff --git > a/audio/ncmpcpp/patches/patch-src_screens_sel_items_adder_cpp > b/audio/ncmpcpp/patches/patch-src_screens_sel_items_adder_cpp > new file mode 100644 > index 00000000000..8f4ca627847 > --- /dev/null > +++ b/audio/ncmpcpp/patches/patch-src_screens_sel_items_adder_cpp > @@ -0,0 +1,16 @@ > +Fix build with libc++22: Boost operator[] proxy breaks template argument > +deduction in LocaleBasedSorting. > +Index: src/screens/sel_items_adder.cpp > +--- src/screens/sel_items_adder.cpp.orig > ++++ src/screens/sel_items_adder.cpp > +@@ -254,7 +254,9 @@ void SelectedItemsAdder::populatePlaylistSelector(Base > + )); > + }; > + std::sort(m_playlist_selector.beginV()+begin, m_playlist_selector.endV(), > +- LocaleBasedSorting(std::locale(), Config.ignore_leading_the)); > ++ [cmp = LocaleBasedSorting(std::locale(), Config.ignore_leading_the)] > ++ (const Entry &a, const Entry &b) { return cmp(a, b); }); > ++ > + if (begin < m_playlist_selector.size()) > + m_playlist_selector.addSeparator(); > + } > diff --git a/audio/ncmpcpp/patches/patch-src_screens_tag_editor_cpp > b/audio/ncmpcpp/patches/patch-src_screens_tag_editor_cpp > new file mode 100644 > index 00000000000..24a6fa9d851 > --- /dev/null > +++ b/audio/ncmpcpp/patches/patch-src_screens_tag_editor_cpp > @@ -0,0 +1,16 @@ > +Fix build with libc++22: Boost operator[] proxy breaks template argument > +deduction in LocaleBasedSorting. > +Index: src/screens/tag_editor.cpp > +--- src/screens/tag_editor.cpp.orig > ++++ src/screens/tag_editor.cpp > +@@ -289,7 +289,9 @@ void TagEditor::update() > + Dirs->highlight(Dirs->size()-1); > + }; > + std::sort(Dirs->beginV()+1, Dirs->endV(), > +- LocaleBasedSorting(std::locale(), Config.ignore_leading_the)); > ++ [cmp = LocaleBasedSorting(std::locale(), Config.ignore_leading_the)] > ++ (const std::pair<std::string, std::string> &a, > ++ const std::pair<std::string, std::string> &b) { return cmp(a, b); }); > + Dirs->display(); > + } > +