The following code example is taken from the book
The C++ Standard Library - A Tutorial and Reference, 2nd Edition
by Nicolai M. Josuttis, Addison Wesley Longman, 2012
Copyright © 2012 by Pearson Education, Inc. and Nicolai M. Josuttis
#include <iostream>
#include <string>
#include <set>
#include <deque>
#include <algorithm>
#include <memory>
class Item {
private:
std::string name;
float price;
public:
Item (const std::string& n, float p = 0) : name(n), price(p) {
}
std::string getName () const {
return name;
}
void setName (const std::string& n) {
name = n;
}
float getPrice () const {
return price;
}
float setPrice (float p) {
price = p;
}
};
template <typename Coll>
void printItems (const std::string& msg, const Coll& coll)
{
std::cout << msg << std::endl;
for (const auto& elem : coll) {
std::cout << ' ' << elem->getName() << ": "
<< elem->getPrice() << std::endl;
}
}
int main()
{
using namespace std;
// two different collections sharing Items
typedef shared_ptr<Item> ItemPtr;
set<ItemPtr> allItems;
deque<ItemPtr> bestsellers;
// insert objects into the collections
// - bestsellers are in both collections
bestsellers = { ItemPtr(new Item("Kong Yize",20.10)),
ItemPtr(new Item("A Midsummer Night's Dream",14.99)),
ItemPtr(new Item("The Maltese Falcon",9.88)) };
allItems = { ItemPtr(new Item("Water",0.44)),
ItemPtr(new Item("Pizza",2.22)) };
allItems.insert(bestsellers.begin(),bestsellers.end());
// print contents of both collections
printItems ("bestsellers:", bestsellers);
printItems ("all:", allItems);
cout << endl;
// double price of bestsellers
for_each (bestsellers.begin(), bestsellers.end(),
[] (shared_ptr<Item>& elem) {
elem->setPrice(elem->getPrice() * 2);
});
// replace second bestseller by first item with name "Pizza"
bestsellers[1] = *(find_if(allItems.begin(),allItems.end(),
[] (shared_ptr<Item> elem) {
return elem->getName() == "Pizza";
}));
// set price of first bestseller
bestsellers[0]->setPrice(44.77);
// print contents of both collections
printItems ("bestsellers:", bestsellers);
printItems ("all:", allItems);
}