Found the following significant warnings:
  /usr/bin/../lib/gcc/x86_64-linux-gnu/14/../../../../include/c++/14/functional:558:2: warning: 'result_of<(lambda at /home/hornik/tmp/R.check/r-devel-clang/Work/build/Packages/RcppEigen/include/unsupported/Eigen/CXX11/src/Tensor/TensorContractionThreadPool.h:1373:13) &()>' is deprecated: use 'std::invoke_result' instead [-Wdeprecated-declarations]
  /usr/bin/../lib/gcc/x86_64-linux-gnu/14/../../../../include/c++/14/functional:558:2: warning: 'result_of<(lambda at /home/hornik/tmp/R.check/r-devel-clang/Work/build/Packages/RcppEigen/include/unsupported/Eigen/CXX11/src/Tensor/TensorContractionThreadPool.h:1392:13) &()>' is deprecated: use 'std::invoke_result' instead [-Wdeprecated-declarations]
  /usr/bin/../lib/gcc/x86_64-linux-gnu/14/../../../../include/c++/14/functional:558:2: warning: 'result_of<(lambda at /home/hornik/tmp/R.check/r-devel-clang/Work/build/Packages/RcppEigen/include/unsupported/Eigen/CXX11/src/Tensor/TensorContractionThreadPool.h:1009:13) &()>' is deprecated: use 'std::invoke_result' instead [-Wdeprecated-declarations]
  /usr/bin/../lib/gcc/x86_64-linux-gnu/14/../../../../include/c++/14/functional:558:2: warning: 'result_of<(lambda at /home/hornik/tmp/R.check/r-devel-clang/Work/build/Packages/RcppEigen/include/unsupported/Eigen/CXX11/src/Tensor/TensorContractionThreadPool.h:1063:15) &()>' is deprecated: use 'std::invoke_result' instead [-Wdeprecated-declarations]
  /usr/bin/../lib/gcc/x86_64-linux-gnu/14/../../../../include/c++/14/functional:558:2: warning: 'result_of<(lambda at /home/hornik/tmp/R.check/r-devel-clang/Work/build/Packages/RcppEigen/include/unsupported/Eigen/CXX11/src/Tensor/TensorContractionThreadPool.h:1082:15) &()>' is deprecated: use 'std::invoke_result' instead [-Wdeprecated-declarations]
See ‘/home/hornik/tmp/R.check/r-devel-clang/Work/PKGS/DAISIE.Rcheck/00install.out’ for details.
* used C compiler: ‘Debian clang version 18.1.0 (rc4-1)’
* used Fortran compiler: ‘Debian flang-new version 18.1.0 (rc4-1)’
* used C++ compiler: ‘Debian clang version 18.1.0 (rc4-1)’