(parameter with reference or pointer)g++ -std=c++11 main.cpp -o main

ptr_test.txt

#include <iostream>
#include <memory>
void foo( const std::shared_ptr<int> p)
{
    static int x = 0;
    *p = ++x;
   // printf("address p %p \n",p);
   // printf("value x %d \n",x );
   // printf("value p %d \n",*p);
}

int main()
{
    auto p = std::make_shared<int>();
    auto start = clock();
    for (int i = 0; i < 10; ++i)
    {
        foo(p);
    }    
    std::cout << "Took " << clock() - start << " ms" << std::endl;
}