an example of using C++ lambda capture, variable a captured by value, variable b captured by reference

👍 g++ -std=c++11 lambda_capture.cpp     
👍 ./a.out
11
7
👍 cat lambda_capture.cpp 
#include <iostream>
using namespace std;

int main() {
  int a = 2, b = 5;
  auto calc = [a, &b](int x) {
    return a * x + b;
  };
  int z = 3;
  cout << calc(z) << endl;
  a = 4; 
  b = 1;
  cout << calc(z) << endl;
}