Building with clang

[abeimler]

Hello,
I have some problems using the clang compiler.
A lot of error: missing 'typename' prior to dependent type name-errors in the tests and other errors with ranges like:

[build] /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/12.2.0/../../../../include/c++/12.2.0/bits/ranges_util.h:139:24: error: constraints not satisfied for alias template 'sentinel_t' [with _Range = const std::ranges::ref_view<const xstd::bit_set<0, unsigned char>>]
[build]         && sized_sentinel_for<sentinel_t<const _Derived>,
[build]                               ^~~~~~~~~~~~~~~~~~~~~~~~~~
[build] /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/12.2.0/../../../../include/c++/12.2.0/bits/ranges_base.h:597:12: note: because 'const std::ranges::ref_view<const xstd::bit_set<0, unsigned char>>' does not satisfy 'range'
[build]   template<range _Range>
[build]            ^
[build] /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/12.2.0/../../../../include/c++/12.2.0/bits/ranges_base.h:585:2: note: because 'ranges::begin(__t)' would be invalid: no matching function for call to object of type 'const __cust_access::_Begin'
[build]         ranges::begin(__t);
[build]         ^
bit_set/test/src/set/o2.cpp:9:
bit_set/test/include/set/parallel.hpp:97:41: error: invalid operands to binary expression ('const xstd::bit_set<0, unsigned char>' and '_Partial<std::ranges::views::_Transform, decay_t<(lambda at bit_set/test/include/set/parallel.hpp:95:25)>>' (aka '_Partial<std::ranges::views::_Transform, (lambda at bit_set/test/include/set/parallel.hpp:95:25)>'))
[build]                                         | std::views::transform([=](auto x) { return x - n; })
[build]                                         ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

But also some errors in the library itself (in my other projects):

 warning: invalid case style for template parameter 'expr-type' [readability-identifier-naming]
/usr/lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/bits/iterator_concepts.h:979:13: error: no matching function for call to '__begin' [clang-diagnostic-error]
         = decltype(ranges::__cust_access::__begin(std::declval<_Tp&>()));
                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/bits/ranges_base.h:586:5: note: in instantiation of template type alias '__range_iter_t' requested here
    using iterator_t = std::__detail::__range_iter_t<_Tp>;
    ^
/usr/lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/bits/ranges_util.h:98:43: note: in instantiation of template type alias 'iterator_t' requested here
       data() requires contiguous_iterator<iterator_t<_Derived>>
                                          ^
 /usr/lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/bits/ranges_util.h:198:29: note: in instantiation of template class 'std::ranges::view_interface<std::ranges::subrange<const int *, const int *, std::ranges::subrange_kind::sized>>' requested here
     class subrange : public view_interface<subrange<_It, _Sent, _Kind>>
                             ^
../bit_set.hpp:257:31: note: in instantiation of template class 'std::ranges::subrange<const int *, const int *, std::ranges::subrange_kind::sized>' requested here
                for (auto x : std::ranges::subrange(first, last)) {
                               ^
../bit_set.hpp:70:17: note: in instantiation of function template specialization 'xstd::bit_set<12>::insert<const int *>' requested here
                insert(first, last);
                ^
../bit_set.hpp:75:17: note: in instantiation of function template specialization 'xstd::bit_set<12>::bit_set<const int *>' requested here
                bit_set(ilist.begin(), ilist.end())
                ^

Also some warnings like error: empty expression statement has no effect; remove unnecessary ';' in some for-loops.

Note:
I'm using vcpkg and added the boost libraries for testing in my project...
cmake -B build -S . -G "Ninja" -DCMAKE_TOOLCHAIN_FILE=./vcpkg/scripts/buildsystems/vcpkg.cmake -DCMAKE_EXPORT_COMPILE_COMMANDS:BOOL=TRUE
https://github.com/abeimler/bit_set/actions/runs/3396267932/jobs/5647138570

Environment:
OS: Linux (Arch Linux 64-Bit)
Compiler: Clang 13

[rhalbersma]

Thanks for filing this issue, and sorry for not responding sooner (notifications were off).

Unfortunately, as I mentioned in the README, this library at the moment does not support Clang since that compiler misses too many C++20 features. In particular excessive use typename has been removed from C++20 and that feature is only supported as of Clang 16. But even Clang 16 is not able to successfully compile gcc's 12 libstdc++ ranges library.

The extra ; after braces were a nice catch, not found by gcc, fixed! Thanks for mentioning that.

I am actively monitoring when Clang is getting a gcc 12 level of C++20 support, but at the moment it's just not there yet.

[rhalbersma]

I've managed to add Clang support, although at the moment that requires Clang 16-SVN, available in packaged form here: https://apt.llvm.org/