Fix error operator

[Quentin62]

Fix https://www.r-project.org/nosvn/R.check/r-devel-linux-x86_64-fedora-clang/RMixtCompIO-00install.html

clang++-22 -stdlib=libc++ -std=gnu++17 -I"/data/gannet/ripley/R/R-clang/include" -DNDEBUG  -I'/data/gannet/ripley/R/test-clang/Rcpp/include' -I'/data/gannet/ripley/R/test-clang/RcppEigen/include' -I'/data/gannet/ripley/R/test-clang/BH/include' -isystem /usr/local/clang22/include -I/usr/local/clang/include   -Ilib -Ilib/LinAlg -DEIGEN_MATRIXBASE_PLUGIN=\"EigenMatrixBaseAddons.h\" -Ioptim/include -fpic  -O3 -Wall -pedantic -frtti -Wp,-D_FORTIFY_SOURCE=3 -Wno-missing-template-arg-list-after-template-kw   -c lib/Composer/ZClassInd.cpp -o lib/Composer/ZClassInd.o
In file included from lib/Composer/MixtureComposer.cpp:25:
In file included from lib/IO/IO.h:26:
In file included from /data/gannet2/ripley/Sources/LLVM/LLVM-22.1.1-Linux-X64/bin/../include/c++/v1/iostream:45:
In file included from /data/gannet2/ripley/Sources/LLVM/LLVM-22.1.1-Linux-X64/bin/../include/c++/v1/ios:228:
In file included from /data/gannet2/ripley/Sources/LLVM/LLVM-22.1.1-Linux-X64/bin/../include/c++/v1/__locale:28:
In file included from /data/gannet2/ripley/Sources/LLVM/LLVM-22.1.1-Linux-X64/bin/../include/c++/v1/string:654:
In file included from /data/gannet2/ripley/Sources/LLVM/LLVM-22.1.1-Linux-X64/bin/../include/c++/v1/string_view:975:
In file included from /data/gannet2/ripley/Sources/LLVM/LLVM-22.1.1-Linux-X64/bin/../include/c++/v1/algorithm:1875:
In file included from /data/gannet2/ripley/Sources/LLVM/LLVM-22.1.1-Linux-X64/bin/../include/c++/v1/__algorithm/make_heap.h:16:
/data/gannet2/ripley/Sources/LLVM/LLVM-22.1.1-Linux-X64/bin/../include/c++/v1/__algorithm/sift_down.h:48:23: error: type 'Eigen::MatrixBase<Eigen::Matrix<double, 1, -1>>::Iterator' does not provide a subscript operator
   48 |     __child += __comp(__first[__child], __first[__child + 1]);
      |                       ^~~~~~~ ~~~~~~~
/data/gannet2/ripley/Sources/LLVM/LLVM-22.1.1-Linux-X64/bin/../include/c++/v1/__algorithm/make_heap.h:49:12: note: in instantiation of function template specialization 'std::__sift_down<std::_ClassicAlgPolicy, true, std::__less<void, void> &, Eigen::MatrixBase<Eigen::Matrix<double, 1, -1>>::Iterator>' requested here
   49 |       std::__sift_down<_AlgPolicy, __assume_both_children>(__first, __comp_ref, __sift_down_n, __start);
      |            ^
/data/gannet2/ripley/Sources/LLVM/LLVM-22.1.1-Linux-X64/bin/../include/c++/v1/__algorithm/partial_sort.h:41:8: note: in instantiation of function template specialization 'std::__make_heap<std::_ClassicAlgPolicy, std::__less<void, void> &, Eigen::MatrixBase<Eigen::Matrix<double, 1, -1>>::Iterator>' requested here
   41 |   std::__make_heap<_AlgPolicy>(__first, __middle, __comp);
      |        ^
/data/gannet2/ripley/Sources/LLVM/LLVM-22.1.1-Linux-X64/bin/../include/c++/v1/__algorithm/partial_sort.h:65:12: note: in instantiation of function template specialization 'std::__partial_sort_impl<std::_ClassicAlgPolicy, std::__less<void, void> &, Eigen::MatrixBase<Eigen::Matrix<double, 1, -1>>::Iterator, Eigen::MatrixBase<Eigen::Matrix<double, 1, -1>>::Iterator>' requested here
   65 |       std::__partial_sort_impl<_AlgPolicy>(__first, __middle, __last, static_cast<__comp_ref_type<_Compare> >(__comp));
      |            ^
/data/gannet2/ripley/Sources/LLVM/LLVM-22.1.1-Linux-X64/bin/../include/c++/v1/__algorithm/sort.h:934:10: note: in instantiation of function template specialization 'std::__partial_sort<std::_ClassicAlgPolicy, std::__less<void, void>, Eigen::MatrixBase<Eigen::Matrix<double, 1, -1>>::Iterator, Eigen::MatrixBase<Eigen::Matrix<double, 1, -1>>::Iterator>' requested here
  934 |     std::__partial_sort<_AlgPolicy>(
      |          ^
/data/gannet2/ripley/Sources/LLVM/LLVM-22.1.1-Linux-X64/bin/../include/c++/v1/__algorithm/sort.h:945:8: note: in instantiation of function template specialization 'std::__sort_impl<std::_ClassicAlgPolicy, Eigen::MatrixBase<Eigen::Matrix<double, 1, -1>>::Iterator, std::__less<void, void>>' requested here
  945 |   std::__sort_impl<_ClassicAlgPolicy>(std::move(__first), std::move(__last), __comp);
      |        ^
/data/gannet2/ripley/Sources/LLVM/LLVM-22.1.1-Linux-X64/bin/../include/c++/v1/__algorithm/sort.h:951:8: note: in instantiation of function template specialization 'std::sort<Eigen::MatrixBase<Eigen::Matrix<double, 1, -1>>::Iterator, std::__less<void, void>>' requested here
  951 |   std::sort(__first, __last, __less<>());
      |        ^
lib/LinAlg/EigenMatrixBaseAddons.h:239:7: note: in instantiation of function template specialization 'std::sort<Eigen::MatrixBase<Eigen::Matrix<double, 1, -1>>::Iterator>' requested here
  239 |         std::sort(derived().begin(), derived().end());
      |              ^
lib/Param/ConfIntParamStat.h:70:13: note: in instantiation of member function 'Eigen::MatrixBase<Eigen::Matrix<double, 1, -1>>::sort' requested here
   70 |                                 currRow.sort();
      |                                         ^
lib/Composer/MixtureComposer.cpp:334:14: note: in instantiation of member function 'mixt::ConfIntParamStat<mixt::Vector<double>>::sampleParam' requested here
  334 |                 paramStat_.sampleParam(iteration, iterationMax);
      |                            ^
In file included from lib/Composer/MixtureComposer.cpp:25:
In file included from lib/IO/IO.h:26:

cran config:

https://www.stats.ox.ac.uk/pub/bdr/Rconfig/r-devel-linux-x86_64-fedora-clang

R-devel
x86_64 Fedora 42 Linux
clang 21.1.1 (C, C++), flang 21.1.1 (Fortran)
Timezone Europe/London
Locale en_GB.UTF-8, LC_COLLATE=C


configured with --without-lapack and config.site:
CC=clang-22
CXX="clang++-22 -stdlib=libc++"
OBJC=$CC
FC=flang-22
CFLAGS="-O3 -Wall -pedantic -Wp,-D_FORTIFY_SOURCE=3"
C17FLAGS="-O3 -Wall -pedantic -Wno-strict-prototypes -Wp,-D_FORTIFY_SOURCE=3"
FFLAGS="-O2 -pedantic"
CXXFLAGS="-O3 -Wall -pedantic -frtti -Wp,-D_FORTIFY_SOURCE=3 -Wno-missing-template-arg-list-after-template-kw"
CPPFLAGS="-isystem /usr/local/clang22/include -I/usr/local/clang/include"
LDFLAGS="-L/usr/local/clang/lib64 -L/usr/local/clang22/lib -L/usr/local/clang22/lib/x86_64-unknown-linux-gnu -L/usr/local/lib64"