C++11: Lambda Expressions: Capture List

In a lambda expression, “[]” and it’s contents define the capture list.

The following are some variations of the capture list:

[] captures nothing

[&] captures all local variables by reference

[=] captures all local variables by value

[this] captures the current object by reference

[a] captures local variable a by copy

[&a] captures local variable a by reference

Here is an example:

#include

int main()

{

  int local1 = 3;

  int local2 = 4;

  [&](int param1, int param2) {std::cout << param1 << " " << param2 << " "

                                         << local1 << " " << local2 << std::endl;}(1, 2);

  return 0;

}

// Output: 1 2 3 4

Reference: http://en.cppreference.com/w/cpp/language/lambda