qtpromise/docs/qtpromise/qpromise/wait.md

QPromise<T>::wait

QPromise<T>::wait() -> QPromise<T>

This method holds the execution of the remaining code until the input promise is resolved (either fulfilled or rejected), without blocking the event loop of the current thread:

int result = -1;

QPromise<int> input = qPromise(QtConcurrent::run([]() {
    return 42;
})).tap([&](int res) {
    result = res;
});

// input.isPending() is true && result is -1

input.wait();

// input.isPending() is false && result is 42