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fhamonic / melon

A graph library using modern C++ features (e.g., C++20 ranges) to be as efficient and user-friendly as possible.
Boost Software License 1.0
33 stars 2 forks source link

contribute? #1

Open pradkrish opened 1 year ago

pradkrish commented 1 year ago

Hello, happy to see a graph library using C++20 features. Is it possible to get involved in this project and help out in small ways? Thank you.

fhamonic commented 1 year ago

Hello, happy to see people interested in contributing :) I see we both opened discussions on stdgraph/graph-v2 which is a C++20 graph library aiming to be standardized (in c++26 probably). Sooner or later, I would like to contribute to this larger project, as I suppose you would. In the meantime, I implement graph algorithms as I need them for another project and focus on efficiency and performances. I use to run some benchmarks against other graph libraries here. I focused on directed graphs and I think that the API for those graphs is definitive (the customization point objects in include/melon/graph.hpp) and is sufficiently close to the one graph-v2 would have, so that transfers are possible in the future.

You can contribute in many ways:

As the library is at a fairly early stage, I am open to any contribution you may want to make.

pradkrish commented 1 year ago

Yeah, you are right. I am trying to use different opportunities to practice C++20 features and I am happy that you are open to contribution. I will take some time to play around with the library to begin with.

As a starter, I am trying to compile the library at the root of the project by simply running make all and I get the following error

  5%] Building CXX object test/CMakeFiles/melon_test.dir/static_digraph_test.cpp.o
[ 10%] Building CXX object test/CMakeFiles/melon_test.dir/main_test.cpp.o
[ 15%] Building CXX object test/CMakeFiles/melon_test.dir/cpo_test.cpp.o
[ 20%] Building CXX object test/CMakeFiles/melon_test.dir/static_forward_digraph_test.cpp.o
/home/pradeep/repos/melon/test/cpo_test.cpp: In function ‘constexpr auto vertices(const G&)’:
/home/pradeep/repos/melon/test/cpo_test.cpp:9:75: error: call to non-‘constexpr’ function ‘std::vector<_Tp, _Alloc>::size_type std::vector<_Tp, _Alloc>::size() const [with _Tp = std::vector<long unsigned int>; _Alloc = std::allocator<std::vector<long unsigned int> >; std::vector<_Tp, _Alloc>::size_type = long unsigned int]’
    9 | constexpr auto vertices(const G & g) { return std::views::iota(0ul, g.size()); }
      |                                                                     ~~~~~~^~
In file included from /usr/include/c++/11/vector:67,
                 from /home/pradeep/.conan/data/gtest/cci.20210126/_/_/package/3926571b75c3e9d8ffdffc9046889c9dc72c974c/include/gtest/gtest.h:60,
                 from /home/pradeep/repos/melon/test/cpo_test.cpp:1:
/usr/include/c++/11/bits/stl_vector.h:918:7: note: ‘std::vector<_Tp, _Alloc>::size_type std::vector<_Tp, _Alloc>::size() const [with _Tp = std::vector<long unsigned int>; _Alloc = std::allocator<std::vector<long unsigned int> >; std::vector<_Tp, _Alloc>::size_type = long unsigned int]’ declared here
  918 |       size() const _GLIBCXX_NOEXCEPT
      |       ^~~~
/home/pradeep/repos/melon/test/cpo_test.cpp: In function ‘constexpr auto out_arcs(const G&, std::size_t)’:
/home/pradeep/repos/melon/test/cpo_test.cpp:11:40: error: call to non-‘constexpr’ function ‘std::vector<_Tp, _Alloc>::const_iterator std::vector<_Tp, _Alloc>::cbegin() const [with _Tp = long unsigned int; _Alloc = std::allocator<long unsigned int>; std::vector<_Tp, _Alloc>::const_iterator = std::vector<long unsigned int>::const_iterator]’
   11 |     return std::views::iota(g[v].cbegin(), g[v].cend());
      |                             ~~~~~~~~~~~^~
In file included from /usr/include/c++/11/vector:67,
                 from /home/pradeep/.conan/data/gtest/cci.20210126/_/_/package/3926571b75c3e9d8ffdffc9046889c9dc72c974c/include/gtest/gtest.h:60,
                 from /home/pradeep/repos/melon/test/cpo_test.cpp:1:
/usr/include/c++/11/bits/stl_vector.h:884:7: note: ‘std::vector<_Tp, _Alloc>::const_iterator std::vector<_Tp, _Alloc>::cbegin() const [with _Tp = long unsigned int; _Alloc = std::allocator<long unsigned int>; std::vector<_Tp, _Alloc>::const_iterator = std::vector<long unsigned int>::const_iterator]’ declared here
  884 |       cbegin() const noexcept
      |       ^~~~~~
In file included from /home/pradeep/repos/melon/test/cpo_test.cpp:23:
/home/pradeep/repos/melon/include/melon/graph.hpp: In substitution of ‘template<class _ValueType, class _Tp>  requires requires(const _Tp& __t) {{}.operator()<_ValueType>(__t);} constexpr auto fhamonic::melon::__cust::create_arc_map(const _Tp&) [with _ValueType = long unsigned int; _Tp = std::vector<std::vector<long unsigned int> >]’:
/home/pradeep/repos/melon/include/melon/graph.hpp:1348:35:   required by substitution of ‘template<class _ValueType, class _Tp>  requires (__member_create_arc_map<_Tp, _ValueType>) || (__adl_create_arc_map<_Tp, _ValueType>) constexpr auto fhamonic::melon::__cust_access::_CreateArcMap::operator()(const _Tp&) const [with _ValueType = long unsigned int; _Tp = std::vector<std::vector<long unsigned int> >]’
/home/pradeep/repos/melon/include/melon/graph.hpp:1414:67:   required by substitution of ‘template<class _ValueType, class _Tp>  requires requires(const _Tp& __t) {{}.operator()<_ValueType>(__t);} constexpr auto fhamonic::melon::__cust::create_arc_map(const _Tp&) [with _ValueType = long unsigned int; _Tp = std::vector<std::vector<long unsigned int> >]’
/home/pradeep/repos/melon/include/melon/graph.hpp:1449:38:   required from here
/home/pradeep/repos/melon/include/melon/graph.hpp:1416:23:   required by the constraints of ‘template<class _ValueType, class _Tp>  requires requires(const _Tp& __t) {{}.operator()<_ValueType>(__t);} constexpr auto fhamonic::melon::__cust::create_arc_map(const _Tp&)’
/home/pradeep/repos/melon/include/melon/graph.hpp:1413:10:   in requirements with ‘const _Tp& __t’ [with _ValueType = long unsigned int; _Tp = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/home/pradeep/repos/melon/include/melon/graph.hpp:1413:10: error: satisfaction of atomic constraint ‘requires(const _Tp& __t) {{}.operator()<_ValueType>(__t);} [with _ValueType = _ValueType; _Tp = _Tp]’ depends on itself
 1413 | requires requires(const _Tp & __t) {
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~
 1414 |     __cust_access::_CreateArcMap{}.template operator()<_ValueType>(__t);
      |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 1415 | }
      | ~         
/home/pradeep/repos/melon/test/cpo_test.cpp: In member function ‘virtual void CPO_test_Test::TestBody()’:
/home/pradeep/repos/melon/test/cpo_test.cpp:45:51: error: no match for call to ‘(const std::ranges::views::_All) (std::vector<std::vector<long unsigned int> >)’
   45 |                   decltype(std::ranges::views::all(std::declval<G>()))>);
      |                            ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~
In file included from /home/pradeep/repos/melon/test/cpo_test.cpp:4:
/usr/include/c++/11/ranges:1117:9: note: candidate: ‘template<class _Range>  requires (viewable_range<_Range>) && ((view<typename std::decay<_Tp>::type>) || (__can_ref_view<_Range>) || (__can_subrange<_Range>)) constexpr auto std::ranges::views::_All::operator()(_Range&&) const’
 1117 |         operator()(_Range&& __r) const
      |         ^~~~~~~~
/usr/include/c++/11/ranges:1117:9: note:   template argument deduction/substitution failed:
/usr/include/c++/11/ranges:1117:9: note: constraints not satisfied
In file included from /usr/include/c++/11/string_view:48,
                 from /usr/include/c++/11/bits/basic_string.h:48,
                 from /usr/include/c++/11/string:55,
                 from /usr/include/c++/11/bits/locale_classes.h:40,
                 from /usr/include/c++/11/bits/ios_base.h:41,
                 from /usr/include/c++/11/ios:42,
                 from /usr/include/c++/11/ostream:38,
                 from /usr/include/c++/11/bits/unique_ptr.h:42,
                 from /usr/include/c++/11/memory:76,
                 from /home/pradeep/.conan/data/gtest/cci.20210126/_/_/package/3926571b75c3e9d8ffdffc9046889c9dc72c974c/include/gtest/gtest.h:57,
                 from /home/pradeep/repos/melon/test/cpo_test.cpp:1:
/home/pradeep/repos/melon/test/cpo_test.cpp: In substitution of ‘template<class _Range>  requires (viewable_range<_Range>) && ((view<typename std::decay<_Tp>::type>) || (__can_ref_view<_Range>) || (__can_subrange<_Range>)) constexpr auto std::ranges::views::_All::operator()(_Range&&) const [with _Range = std::vector<std::vector<long unsigned int> >]’:
/home/pradeep/repos/melon/test/cpo_test.cpp:45:51:   required from here
/usr/include/c++/11/bits/ranges_base.h:666:13:   required for the satisfaction of ‘viewable_range<_Range>’ [with _Range = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/usr/include/c++/11/bits/ranges_base.h:668:11: note: no operand of the disjunction is satisfied
  667 |       && ((view<remove_cvref_t<_Tp>> && constructible_from<remove_cvref_t<_Tp>, _Tp>)
      |          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  668 |           || (!view<remove_cvref_t<_Tp>> && borrowed_range<_Tp>));
      |           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/11/bits/ranges_base.h:667:38: note: the operand ‘(view<typename std::remove_cvref<_Tp>::type> && constructible_from<typename std::remove_cvref<_Tp>::type, _Tp>)’ is unsatisfied because
  667 |       && ((view<remove_cvref_t<_Tp>> && constructible_from<remove_cvref_t<_Tp>, _Tp>)
      |          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  668 |           || (!view<remove_cvref_t<_Tp>> && borrowed_range<_Tp>));
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/11/bits/ranges_base.h:621:13:   required for the satisfaction of ‘view<typename std::remove_cvref<_Tp>::type>’ [with _Tp = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/usr/include/c++/11/bits/ranges_base.h:666:13:   required for the satisfaction of ‘viewable_range<_Range>’ [with _Range = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/usr/include/c++/11/bits/ranges_base.h:622:39: note: the expression ‘enable_view<_Tp> [with _Tp = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]’ evaluated to ‘false’
  622 |       = range<_Tp> && movable<_Tp> && enable_view<_Tp>;
      |                                       ^~~~~~~~~~~~~~~~
/usr/include/c++/11/bits/ranges_base.h:668:42: note: the operand ‘((! view<typename std::remove_cvref<_Tp>::type>) && borrowed_range<_Tp>)’ is unsatisfied because
  667 |       && ((view<remove_cvref_t<_Tp>> && constructible_from<remove_cvref_t<_Tp>, _Tp>)
      |          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  668 |           || (!view<remove_cvref_t<_Tp>> && borrowed_range<_Tp>));
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/11/bits/ranges_base.h:83:15:   required for the satisfaction of ‘__maybe_borrowed_range<_Tp>’ [with _Tp = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/usr/include/c++/11/bits/ranges_base.h:582:13:   required for the satisfaction of ‘borrowed_range<_Tp>’ [with _Tp = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/usr/include/c++/11/bits/ranges_base.h:666:13:   required for the satisfaction of ‘viewable_range<_Range>’ [with _Range = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/usr/include/c++/11/bits/ranges_base.h:85:11: note: no operand of the disjunction is satisfied
   84 |         = is_lvalue_reference_v<_Tp>
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~
   85 |           || enable_borrowed_range<remove_cvref_t<_Tp>>;
      |           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/11/bits/ranges_base.h:84:11: note: the operand ‘is_lvalue_reference_v<_Tp>’ is unsatisfied because
   84 |         = is_lvalue_reference_v<_Tp>
      |           ^~~~~~~~~~~~~~~~~~~~~~~~~~
   85 |           || enable_borrowed_range<remove_cvref_t<_Tp>>;
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/11/bits/ranges_base.h:83:15:   required for the satisfaction of ‘__maybe_borrowed_range<_Tp>’ [with _Tp = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/usr/include/c++/11/bits/ranges_base.h:582:13:   required for the satisfaction of ‘borrowed_range<_Tp>’ [with _Tp = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/usr/include/c++/11/bits/ranges_base.h:666:13:   required for the satisfaction of ‘viewable_range<_Range>’ [with _Range = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/usr/include/c++/11/bits/ranges_base.h:84:11: note: the expression ‘is_lvalue_reference_v<_Tp> [with _Tp = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]’ evaluated to ‘false’
   84 |         = is_lvalue_reference_v<_Tp>
      |           ^~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/11/bits/ranges_base.h:85:14: note: the operand ‘enable_borrowed_range<std::remove_cvref_t<_Tp1> >’ is unsatisfied because
   84 |         = is_lvalue_reference_v<_Tp>
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~
   85 |           || enable_borrowed_range<remove_cvref_t<_Tp>>;
      |           ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/11/bits/ranges_base.h:83:15:   required for the satisfaction of ‘__maybe_borrowed_range<_Tp>’ [with _Tp = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/usr/include/c++/11/bits/ranges_base.h:582:13:   required for the satisfaction of ‘borrowed_range<_Tp>’ [with _Tp = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/usr/include/c++/11/bits/ranges_base.h:666:13:   required for the satisfaction of ‘viewable_range<_Range>’ [with _Range = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/usr/include/c++/11/bits/ranges_base.h:85:14: note: the expression ‘enable_borrowed_range<typename std::remove_cvref<_Tp>::type> [with _Tp = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]’ evaluated to ‘false’
   85 |           || enable_borrowed_range<remove_cvref_t<_Tp>>;
      |              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/pradeep/repos/melon/test/cpo_test.cpp:45:51: error: no match for call to ‘(const std::ranges::views::_All) (std::vector<std::vector<long unsigned int> >)’
   45 |                   decltype(std::ranges::views::all(std::declval<G>()))>);
      |                            ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~
In file included from /home/pradeep/repos/melon/test/cpo_test.cpp:4:
/usr/include/c++/11/ranges:1117:9: note: candidate: ‘template<class _Range>  requires (viewable_range<_Range>) && ((view<typename std::decay<_Tp>::type>) || (__can_ref_view<_Range>) || (__can_subrange<_Range>)) constexpr auto std::ranges::views::_All::operator()(_Range&&) const’
 1117 |         operator()(_Range&& __r) const
      |         ^~~~~~~~
/usr/include/c++/11/ranges:1117:9: note:   template argument deduction/substitution failed:
/usr/include/c++/11/ranges:1117:9: note: constraints not satisfied
In file included from /usr/include/c++/11/string_view:48,
                 from /usr/include/c++/11/bits/basic_string.h:48,
                 from /usr/include/c++/11/string:55,
                 from /usr/include/c++/11/bits/locale_classes.h:40,
                 from /usr/include/c++/11/bits/ios_base.h:41,
                 from /usr/include/c++/11/ios:42,
                 from /usr/include/c++/11/ostream:38,
                 from /usr/include/c++/11/bits/unique_ptr.h:42,
                 from /usr/include/c++/11/memory:76,
                 from /home/pradeep/.conan/data/gtest/cci.20210126/_/_/package/3926571b75c3e9d8ffdffc9046889c9dc72c974c/include/gtest/gtest.h:57,
                 from /home/pradeep/repos/melon/test/cpo_test.cpp:1:
/home/pradeep/repos/melon/test/cpo_test.cpp: In substitution of ‘template<class _Range>  requires (viewable_range<_Range>) && ((view<typename std::decay<_Tp>::type>) || (__can_ref_view<_Range>) || (__can_subrange<_Range>)) constexpr auto std::ranges::views::_All::operator()(_Range&&) const [with _Range = std::vector<std::vector<long unsigned int> >]’:
/home/pradeep/repos/melon/test/cpo_test.cpp:45:51:   required from here
/usr/include/c++/11/bits/ranges_base.h:666:13:   required for the satisfaction of ‘viewable_range<_Range>’ [with _Range = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/usr/include/c++/11/bits/ranges_base.h:668:11: note: no operand of the disjunction is satisfied
  667 |       && ((view<remove_cvref_t<_Tp>> && constructible_from<remove_cvref_t<_Tp>, _Tp>)
      |          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  668 |           || (!view<remove_cvref_t<_Tp>> && borrowed_range<_Tp>));
      |           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/11/bits/ranges_base.h:667:38: note: the operand ‘(view<typename std::remove_cvref<_Tp>::type> && constructible_from<typename std::remove_cvref<_Tp>::type, _Tp>)’ is unsatisfied because
  667 |       && ((view<remove_cvref_t<_Tp>> && constructible_from<remove_cvref_t<_Tp>, _Tp>)
      |          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  668 |           || (!view<remove_cvref_t<_Tp>> && borrowed_range<_Tp>));
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/11/bits/ranges_base.h:621:13:   required for the satisfaction of ‘view<typename std::remove_cvref<_Tp>::type>’ [with _Tp = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/usr/include/c++/11/bits/ranges_base.h:666:13:   required for the satisfaction of ‘viewable_range<_Range>’ [with _Range = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/usr/include/c++/11/bits/ranges_base.h:622:39: note: the expression ‘enable_view<_Tp> [with _Tp = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]’ evaluated to ‘false’
  622 |       = range<_Tp> && movable<_Tp> && enable_view<_Tp>;
      |                                       ^~~~~~~~~~~~~~~~
/usr/include/c++/11/bits/ranges_base.h:668:42: note: the operand ‘((! view<typename std::remove_cvref<_Tp>::type>) && borrowed_range<_Tp>)’ is unsatisfied because
  667 |       && ((view<remove_cvref_t<_Tp>> && constructible_from<remove_cvref_t<_Tp>, _Tp>)
      |          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  668 |           || (!view<remove_cvref_t<_Tp>> && borrowed_range<_Tp>));
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/11/bits/ranges_base.h:83:15:   required for the satisfaction of ‘__maybe_borrowed_range<_Tp>’ [with _Tp = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/usr/include/c++/11/bits/ranges_base.h:582:13:   required for the satisfaction of ‘borrowed_range<_Tp>’ [with _Tp = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/usr/include/c++/11/bits/ranges_base.h:666:13:   required for the satisfaction of ‘viewable_range<_Range>’ [with _Range = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/usr/include/c++/11/bits/ranges_base.h:85:11: note: no operand of the disjunction is satisfied
   84 |         = is_lvalue_reference_v<_Tp>
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~
   85 |           || enable_borrowed_range<remove_cvref_t<_Tp>>;
      |           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/11/bits/ranges_base.h:84:11: note: the operand ‘is_lvalue_reference_v<_Tp>’ is unsatisfied because
   84 |         = is_lvalue_reference_v<_Tp>
      |           ^~~~~~~~~~~~~~~~~~~~~~~~~~
   85 |           || enable_borrowed_range<remove_cvref_t<_Tp>>;
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/11/bits/ranges_base.h:83:15:   required for the satisfaction of ‘__maybe_borrowed_range<_Tp>’ [with _Tp = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/usr/include/c++/11/bits/ranges_base.h:582:13:   required for the satisfaction of ‘borrowed_range<_Tp>’ [with _Tp = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/usr/include/c++/11/bits/ranges_base.h:666:13:   required for the satisfaction of ‘viewable_range<_Range>’ [with _Range = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/usr/include/c++/11/bits/ranges_base.h:84:11: note: the expression ‘is_lvalue_reference_v<_Tp> [with _Tp = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]’ evaluated to ‘false’
   84 |         = is_lvalue_reference_v<_Tp>
      |           ^~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/11/bits/ranges_base.h:85:14: note: the operand ‘enable_borrowed_range<std::remove_cvref_t<_Tp1> >’ is unsatisfied because
   84 |         = is_lvalue_reference_v<_Tp>
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~
   85 |           || enable_borrowed_range<remove_cvref_t<_Tp>>;
      |           ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/11/bits/ranges_base.h:83:15:   required for the satisfaction of ‘__maybe_borrowed_range<_Tp>’ [with _Tp = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/usr/include/c++/11/bits/ranges_base.h:582:13:   required for the satisfaction of ‘borrowed_range<_Tp>’ [with _Tp = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/usr/include/c++/11/bits/ranges_base.h:666:13:   required for the satisfaction of ‘viewable_range<_Range>’ [with _Range = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]
/usr/include/c++/11/bits/ranges_base.h:85:14: note: the expression ‘enable_borrowed_range<typename std::remove_cvref<_Tp>::type> [with _Tp = std::vector<std::vector<long unsigned int, std::allocator<long unsigned int> >, std::allocator<std::vector<long unsigned int, std::allocator<long unsigned int> > > >]’ evaluated to ‘false’
   85 |           || enable_borrowed_range<remove_cvref_t<_Tp>>;
      |              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/pradeep/repos/melon/test/cpo_test.cpp:44:32: error: template argument 1 is invalid
   44 |     static_assert(std::ranges::contiguous_range<
      |                                ^~~~~~~~~~~~~~~~~
   45 |                   decltype(std::ranges::views::all(std::declval<G>()))>);
      |                   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[ 25%] Building CXX object test/CMakeFiles/melon_test.dir/dumb_digraph_test.cpp.o

is this expected? Thanks.

fhamonic commented 1 year ago

Hi, The compiler is complaining about constexpr on vector::size(), maybe I used constexpr a little too much, but here vector::size() should work since C++20, try GCC 12 I think.

pradkrish commented 1 year ago

Thanks, that worked :)