tf::Executor executor;

tf::Taskflow taskflow;

auto [source, swcond, case1, case2, case3, target] = taskflow.emplace(

[](){ std::cout << "source\n"; },

[](){ std::cout << "switch\n"; return rand()%3; },

[](){ std::cout << "case 1\n"; return 0; },

[](){ std::cout << "case 2\n"; return 0; },

[](){ std::cout << "case 3\n"; return 0; },

[](){ std::cout << "target\n"; }

);

source.precede(swcond);

swcond.precede(case1, case2, case3);

target.succeed(case1, case2, case3);

executor.run(taskflow).wait();

return 0;