#include void do_something(int& i) { ++i; } struct func { int& i; func(int& i_):i(i_){} void operator()() { for(unsigned j=0;j<1000000;++j) { do_something(i); } } }; void oops() { int some_local_state=0; func my_func(some_local_state); std::thread my_thread(my_func); my_thread.detach(); } int main() { oops(); }