lambda, std::function, std::bind

int _lambda0(int x, int y)
{
return (x + y + x * y) * 2;
}


void test_lambda()
{
auto _lambda1 = [] (int x, int y) {
return x + y + x * y;
};


std::function<int(int, int)> _lambda2 = _lambda1;


std::function<int(int, int)> _lambda3 = _lambda0;

using namespace std::placeholders;


std::function<int(int)> _lambda4 = std::bind(_lambda0, _1, 20);


int a = _lambda1(10, 20);
int b = _lambda2(10, 20);
int c = _lambda3(10, 20);
int d = _lambda4(10);


printf("%d, %d, %d", a, b, c);

}

用起来就这些了，不必理论，弄死脑细胞。