onetoomany

/* onetoomany.cpp constructs 11 items instead of 10 */
#include <iostream>
#include <vector>

struct Item
{
public:
  static size_t  ctorCount;
  static size_t  dtorCount;
  static size_t  cpctorCount;

  Item() { ctorCount++; }
  ~Item() { dtorCount++; }
  Item(const Item& item){ cpctorCount++; }
};

// must initialize static memebers out of line
size_t Item::ctorCount   = 0;
size_t Item::dtorCount   = 0;
size_t Item::cpctorCount = 0;

//creates count items in vector
void populate( std::vector<Item> & vec, int count)
{
  vec.reserve(count);
  vec.assign(count, Item());
}

int main()
{
 size_t count = 10;
 std::vector<Item> vec;
 populate( vec, count);

 std::cout << "Size of vec:\t"
       << vec.size() << std::endl;

  std::cout<<"Total Item Objects constructed = "
       << (Item::ctorCount + Item::cpctorCount)
       << "\n";

  std::cout<<"Constructor called "
       <<  Item::ctorCount << " times"
       << "\n";

  std::cout<<"Copy Constructor called "
       << Item::cpctorCount <<" times"
       << "\n";

  std::cout<<"Total Item Objects destructed = "
       <<Item::dtorCount
       <<std::endl;

}

/** OUTPUT

Size of vec:    10
Total Item Objects constructed = 11
Constructor called 1 times
Copy Constructor called 10 times
Total Item Objects destructed = 1

**/