Stop it
std::unique_ptr<Connection> HandleRead(std::unique_ptr<Connection> connection) { // do some things } std::vector<pollfd> poll_args; std::vector<std::unique_ptr<Connection>> fd_to_connection; // some instructions later for (size_t i = 1; i < poll_args.size(); i++) { std::unique_ptr<Connection> connection = std::move(fd_to_connection[poll_args[i].fd]); if (ready & POLLIN) { fd_to_connection[connection->fd] = std::move(HandleRead(std::move(connection))); } // other }
Look how clever I was. Thought I could get it into one line
However, std::move(connection) evaluates and moves connection out of scope. Later call to connection->fd will segfault.
Grab what you need before you move it...
std::unique_ptr<Connection> HandleRead(std::unique_ptr<Connection> connection) { // do some things } std::vector<pollfd> poll_args; std::vector<std::unique_ptr<Connection>> fd_to_connection; // some instructions later for (size_t i = 1; i < poll_args.size(); i++) { std::unique_ptr<Connection> connection = std::move(fd_to_connection[poll_args[i].fd]); // solution: int fd_index = connection->fd; if (ready & POLLIN) { // better, no segfault: fd_to_connection[fd_index] = std::move(HandleRead(std::move(connection))); } // other }