#include <thread>
#include <iostream>
 
using namespace std;
 
int main()
{
  thread t1([] {
    cout << "Launching Scud missile" << endl;
  });
  t1.join();
  return 0;
}

A lambda closure is nothing but a variable storing a lambda expression.

You can store a lambda in a closure if you intend to reuse the lambda expression at more than one place in your code.

#include <thread>
#include <iostream>
 
using namespace std;
 
int main()
{
  // Define a lambda closure
  auto LaunchMissileFunc = []() -> void { cout << "Launching Cruiser Missile" << endl; };
  thread t1(LaunchMissileFunc);
  t1.join();
  return 0;
}

auto LaunchTorpedoFunc = [](int numCities, string torpedoType) -> void { cout << "Firing torpedo " << torpedoType << " at" << numCities << " cities." << endl; };
thread t1(LaunchTorpedoFunc, 7, "Barracuda");
t1.join();