void Core<T>::resolve(const Promise<T>& promise) { if (_status != PENDING) throw std::runtime_error("The promise is already resolve or reject"); Promise<T> p = promise; Deferred<T> d(lock()); p.then([d] (const T& value) mutable { d.resolve(value); }); p.otherwise([d] (const std::string& err) mutable { d.reject(err); }); }
int main() { Deferred<int> defer = deferred<int>(); Promise<int> p = defer.promise(); Promise<std::string> p2 = p.then ([] (int a) -> std::string { std::cout << "Defered was resolved with [" << a << "]" << std::endl; return "Success"; }); p.otherwise([] (const std::string& error) -> void { std::cout << "Defer was rejected with [" << error << "]" << std::endl; }); auto p3 = p2.then([] (const std::string& result) -> void { std::cout << "2nd Defer was resolved with [" << result << "]" << std::endl; }); p2.otherwise([] ( const std::string& err) { std::cout << "2nd Defer was rejected with [" << err << "]" << std::endl; }); p3.then ([] (const bool& b) { std::cout << "3rd defer resolved with [" << b << "]" << std::endl; }); // defer.resolve(42); // // OR // // defer.reject("There was an error"); // }