[question] how do we `bulk` a batch of `senders` ?

[anonymouspc]

Suppose we have an async operation:

stdexec::sender auto tcp::socket::async_connect(endpoint);

Now we try to connect a batch of endpoints, and wait for all/any of them.

stdexec::sender auto task_1 = socket_1.async_connect("127.0.0.1:1");
stdexec::sender auto task_2 = socket_2.async_connect("127.0.0.1:2");
stdexec::sender auto task_3 = socket_3.async_connect("127.0.0.1:3");
/* ... */
stdexec::sender auto task_65535 = socket_65535.async_connect("127.0.0.1:65535");
stdexec::sync_wait(stdexec::when_all(task_1, task_2, task_3, /*...*/, task_65535));

The functions above are all senders instead of synchronous functions (that is, submit task and later callback). Although we can bulk synchronous functions using stdexec::bulk(policy, shape, sync_func), I wonder: is there a function that we can stdexec::/*bulk_what*/(policy, shape, func_who_returns_sender)? I tried hard to read the docs but sadly could not find it.

auto sockets = std::vector<tcp::socket>(65535);
stdexec::sync_wait(stdexec::/*let_bulk_or_some_name_else?*/(
    stdexec::par,
    65535,
    [&] { return sockets[i].async_connect(std::format("127.0.0.1:{}", i); }
)

Thank you!

[lixin-wei]

It think there lacks a when_all(sender_range) sender adaptor, may be you can implement one by yourself.

stdexec::bulk(policy, shape, sync_func) you said is not the correct way. Senders are lazy, by this way you only trigger them one by one(if policy is seq), they are not executed in parallel.