The funny thing is that select's APIs are compatible with a non-broken implementation, such as something that heap allocates if above a constant size. My recoll

The funny thing is that select's APIs are compatible with a non-broken implementation, such as something that heap allocates if above a constant size. My recollection is that some implementations (winsock?) even do this. Of course, that's never going to actually happen on implementations people care about between ABI breaking on the one hand and the existence of poll/epoll on the other. (My biggest concern in practice is random shitty libraries using select behind the scenes and then silently corrupting memory in processes that have more than a few file descriptors.)