The right way to wait for input after sigaction handling ctrl+c aka SIGINT

Question

This program will print infinite "Enter a:" to the command line, after sending SIGINT via Ctrl + C. To exit this loop, I use Ctrl + \. If I uncomment the line containing std::cin.clear();, everything works fine. My question is, is this the right way to do it? One would have to set std::cin.clear(); in front of every cin/cout he wants the program to wait for. That's why it seems not to be the proper way to me.

#include<iostream>
#include<signal.h>

void sig_handler(int s)
{
  std::cout << "Cought: " << s << std::endl;
  // do something...
}


int main ()
{
  struct sigaction sigIntHandler;
  sigIntHandler.sa_handler = sig_handler;
  sigemptyset(&sigIntHandler.sa_mask);
  sigIntHandler.sa_flags = 0;
  sigaction(SIGINT, &sigIntHandler, NULL);
  int a=1;
  while(a)
    {
      std::cout << "Enter a:" << std::endl;
      //std::cin.clear(); // Uncomment me!
      std::cin >> a;
    }
}

PS: I know that cout in signal handlers are a bad idea.

PPS: Everything works fine (without std::cin.clear();) when I use the old (deprecated) signal().

PPPS: Just to make it clear, I do not want to exit the program on Ctrl + C!