Found the following significant warnings:
  /home/hornik/tmp/R.check/r-devel-gcc/Work/build/Packages/RcppParallel/include/tbb/internal/_concurrent_unordered_impl.h:1213:15: warning: ‘void* memset(void*, int, size_t)’ clearing an object of type ‘struct tbb::atomic<tbb::interface5::internal::flist_iterator<tbb::interface5::internal::split_ordered_list<std::pair<const std::vector<unsigned int>, std::pair<tbb::atomic<unsigned int>, tbb::atomic<unsigned int> > >, tbb::tbb_allocator<std::pair<const std::vector<unsigned int>, std::pair<tbb::atomic<unsigned int>, tbb::atomic<unsigned int> > > > >, std::pair<const std::vector<unsigned int>, std::pair<tbb::atomic<unsigned int>, tbb::atomic<unsigned int> > > >*>’ with no trivial copy-assignment; use assignment or value-initialization instead [-Wclass-memaccess]
  /home/hornik/tmp/R.check/r-devel-gcc/Work/build/Packages/RcppParallel/include/tbb/internal/_concurrent_unordered_impl.h:1213:15: warning: ‘void* memset(void*, int, size_t)’ clearing an object of type ‘struct tbb::atomic<tbb::interface5::internal::flist_iterator<tbb::interface5::internal::split_ordered_list<unsigned int, tbb::tbb_allocator<unsigned int> >, unsigned int>*>’ with no trivial copy-assignment; use assignment or value-initialization instead [-Wclass-memaccess]
  /home/hornik/tmp/R.check/r-devel-gcc/Work/build/Packages/RcppParallel/include/tbb/internal/_concurrent_unordered_impl.h:1213:15: warning: ‘void* memset(void*, int, size_t)’ clearing an object of type ‘struct tbb::atomic<tbb::interface5::internal::flist_iterator<tbb::interface5::internal::split_ordered_list<std::vector<unsigned int>, tbb::tbb_allocator<std::vector<unsigned int> > >, std::vector<unsigned int> >*>’ with no trivial copy-assignment; use assignment or value-initialization instead [-Wclass-memaccess]
  /home/hornik/tmp/R.check/r-devel-gcc/Work/build/Packages/RcppParallel/include/tbb/internal/_concurrent_unordered_impl.h:1213:15: warning: ‘void* memset(void*, int, size_t)’ clearing an object of type ‘struct tbb::atomic<tbb::interface5::internal::flist_iterator<tbb::interface5::internal::split_ordered_list<std::pair<const std::vector<unsigned int>, tbb::atomic<unsigned int> >, tbb::tbb_allocator<std::pair<const std::vector<unsigned int>, tbb::atomic<unsigned int> > > >, std::pair<const std::vector<unsigned int>, tbb::atomic<unsigned int> > >*>’ with no trivial copy-assignment; use assignment or value-initialization instead [-Wclass-memaccess]
See ‘/home/hornik/tmp/R.check/r-devel-gcc/Work/PKGS/quanteda.Rcheck/00install.out’ for details.