Qt6 and range-v3 error build telegram desktop with clang 13-14

[h0tc0d3]

In file included from <built-in>:484:
In file included from /build/telegram-desktop+clang/src/build/Telegram/CMakeFiles/Telegram.dir/cmake_pch.hxx:5:
In file included from /build/telegram-desktop+clang/src/tdesktop-3.6.0-full/Telegram/SourceFiles/stdafx.h:102:
In file included from /usr/include/range/v3/all.hpp:17:
In file included from /usr/include/range/v3/action.hpp:32:
In file included from /usr/include/range/v3/action/split.hpp:28:
/usr/include/range/v3/range/conversion.hpp:379:29: error: alias template 'QVector' requires template arguments; argument deduction only allowed for class templates
                -> decltype(ContT(range_cpp17_iterator_t<Rng>{},
                            ^
/usr/include/meta/meta.hpp:541:5: note: in instantiation of template class 'ranges::detail::from_range<QVector>' requested here
    using invoke = typename Fn::template invoke<Args...>;
    ^
/usr/include/range/v3/range/conversion.hpp:46:13: note: in instantiation of template type alias 'invoke' requested here
            using container_t = meta::invoke<MetaFn, Rng>;
            ^
/usr/include/range/v3/range/conversion.hpp:338:46: note: in instantiation of template type alias 'container_t' requested here
                    convertible_to_cont<Rng, container_t<MetaFn, Rng>>)
                                             ^
/usr/include/range/v3/detail/prologue.hpp:35:26: note: expanded from macro 'template'
    template<__VA_ARGS__ CPP_TEMPLATE_AUX_                                      \
                         ^
/usr/include/range/v3/range/conversion.hpp:304:13: note: in instantiation of template class 'ranges::detail::to_container::fn<ranges::detail::from_range<QVector>>' requested here
          , Fn
            ^
/usr/include/range/v3/range/conversion.hpp:425:20: note: in instantiation of template class 'ranges::detail::to_container::closure<ranges::detail::from_range<QVector>, ranges::detail::to_container::fn<ranges::detail::from_range<QVector>>>' requested here
            return detail::to_container_fn<detail::from_range<ContT>>{}(
                   ^
/build/telegram-desktop+clang/src/tdesktop-3.6.0-full/Telegram/SourceFiles/api/api_media.cpp:86:12: note: in instantiation of function template specialization 'ranges::_to_::to<QVector, std::vector<tl::boxed<MTPinputDocument>> &>' requested here
                        ranges::to<QVector>(info.attachedStickers)),
                                ^
/usr/include/qt6/QtCore/qcontainerfwd.h:63:22: note: template is declared here
template<typename T> using QVector = QList<T>;
                     ^
In file included from <built-in>:484:
In file included from /build/telegram-desktop+clang/src/build/Telegram/CMakeFiles/Telegram.dir/cmake_pch.hxx:5:
In file included from /build/telegram-desktop+clang/src/tdesktop-3.6.0-full/Telegram/SourceFiles/stdafx.h:102:
In file included from /usr/include/range/v3/all.hpp:17:
In file included from /usr/include/range/v3/action.hpp:32:
In file included from /usr/include/range/v3/action/split.hpp:28:
/usr/include/range/v3/range/conversion.hpp:425:20: error: type 'detail::to_container_fn<detail::from_range<QVector>>' (aka 'closure<ranges::detail::from_range<QVector>, ranges::detail::to_container::fn<ranges::detail::from_range<QVector>>>') does not provide a call operator
            return detail::to_container_fn<detail::from_range<ContT>>{}(
                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/build/telegram-desktop+clang/src/tdesktop-3.6.0-full/Telegram/SourceFiles/api/api_media.cpp:86:12: note: in instantiation of function template specialization 'ranges::_to_::to<QVector, std::vector<tl::boxed<MTPinputDocument>> &>' requested here
                        ranges::to<QVector>(info.attachedStickers)),
                                ^
2 errors generated.

[JohelEGP]

That's a language limitation due to a feature Clang has yet to implement. This can't be fixed on Range-v3's side, so you'd have to report to whomever is calling ranges::to<QVector>.

[h0tc0d3]

@JohelEGP affects llvm 14 too. So it's not a compiler problem, your library probably violates some of the standards. Because clang gives the best search for errors in the code.

[JohelEGP]

Clang hasn't implemented the feature yet, so it doesn't matter whether it's Clang 14 or 15, except that there's a possibility it's implemented for Clang 15 before its feature freeze.

The feature is "Class template argument deduction for alias templates" at https://en.cppreference.com/w/cpp/compiler_support.