#include <vector>
#include <algorithm>
using namespace std;

int main()
{
  vector<int> num = { 1, 2, 3, 4 };
  int sum = 0;
  auto lamda = [&sum](int i) { sum += i; };
  
  lambda(1);
  for_each(num.begin(), num.end(), lambda);

  return 0;
}

sum = lambda x, y: x + y
sum(1, 2)