move.cpp

#include <functional>
#include <memory>
#include <stdio.h>

typedef std::function<void()> Task;

void onRead() { printf("onRead\n"); }
void onTimeout() { printf("onTimeout\n"); }

void wait(void* ep, Task&& onRead, Task&& onWrite, Task&& onTimeout) {
    printf("wait@%p\n", ep);
    if (onRead) onRead();
    if (onWrite) onWrite();
    if (onTimeout) onTimeout();
}

int main() {
    wait(nullptr, std::bind(onRead), nullptr, &onTimeout);
    return 0;
}

trapni@stormsore [~/projects] > ./move
wait@(nil)
onRead
onTimeout