ex13_13.cpp

//
//  ex13_13.cpp
//  CP5
//
//  Created by pezy on 1/13/15.
//  Copyright (c) 2015 pezy. All rights reserved.
//
//  A good way to understand copy-control members and constructors is to define
//  a simple class with these members in which each member prints its name:
//  struct X {
//    X() {std::cout << "X()" << std::endl;}
//    X(const X&) {std::cout << "X(const X&)" << std::endl;}
//  };
//  Add the copy-assignment operator and destructor to X and write a program
//  using X objects in various ways:
//  Pass them as nonreference and reference parameters;
//  dynamically allocate them;
//  put them in containers; and so forth.
//  Study the output until you are certain you understand when and why each
//  copy-control member is used.
//  As you read the output, remember that the compiler can omit calls to the
//  copy constructor.

#include <iostream>
#include <vector>
#include <initializer_list>

struct X {
    X() { std::cout << "X()" << std::endl; }
    X(const X&) { std::cout << "X(const X&)" << std::endl; }
    X& operator=(const X&)
    {
        std::cout << "X& operator=(const X&)" << std::endl;
        return *this;
    }
    ~X() { std::cout << "~X()" << std::endl; }
};

void f(const X& rx, X x)
{
    std::vector<X> vec;
    vec.reserve(2);
    vec.push_back(rx);
    vec.push_back(x);
}

int main()
{
    X* px = new X;
    f(*px, *px);
    delete px;

    return 0;
}