gistfile1.txt

main.cc:128:46: error: implicit instantiation of undefined template 'std::function<std::packaged_task<int ()> >'
      std::function<std::packaged_task<T()>> unbound = [](std::packaged_task<T()> bound_task)->void {
                                             ^
main.cc:148:17: note: in instantiation of function template specialization 'SimpleThreadPool::Submit<int>' requested here
  auto res = tp.Submit<int>([]()->int {
                ^
functional:1866:11: note: template is declared here
    class function;
          ^
1 error generated.
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