Question

Make a class, named "ConstructorCounter", that has a function member named "num_constructed". This function takes no parameters, but returns an int that is the number of instances of the class ConstructionCounter. Hint: you will need to use non-synthetic methods and statics to solve this problem.

all in one file, and they should be in the class. do not need main func, but you can have main to test them.

INPUT OF THE TEST CASE ASSERT_EQ(0, ConstructorCounter::num_constructed(); 1 ConstructorCounter c; 2 3 ASSERT_EQ(1, ConstructorCounter::num_constructed(); INPUT OF THE TEST CASE 1 ASSERT_EQ(0, ConstructorCounter::num_constructed( )); 2 ConstructorCounter c; ASSERT_EQ(1, ConstructorCounter:num_constructed ( ) ); 4 ConstructorCounter d; 5 ASSERT_EQ(2, ConstructorCounter::num_constructed()); ASSERT_EQ(2, ConstructorCounter::num_constructed()); 7 { Constructor Counter e; ASSERT_EQ(3, ConstructorCounter::num_constructed()); 10 } ASSERT_EQ(2, ConstructorCounter::num_constructed(); 11 INPUT OF THE TEST CASE 1 ASSERT_EQ(0, ConstructorCounter::num_constructed (O); 2 ConstructorCounter c; 3 ASSERT_EQ(1, ConstructorCounter::num_constructed() ); 4 ConstructorCounter d(c); ASSERT_EQ(2, ConstructorCounter::num_constructed()); ASSERT_EQ(2, ConstructorCounter::num_constructed( ) ); 7 { ConstructorCounter e = d; ASSERT_EQ(3, ConstructorCounter::num_constructed()); 10 } ASSERT_EQ(2, ConstructorCounter::num_constructed()); 11

Answer 1

Solution:

Code:

#include <iostream>
class ConstructorCounter {
public:
   ConstructorCounter() { ++count; }
   ConstructorCounter(const ConstructorCounter&) { ++count; }
   ~ConstructorCounter() { --count; }

   static size_t num_constructed()
   {
       return count;
   }

private:
   static size_t count;
};
size_t ConstructorCounter::count = 0;

// Main function to test implementation
int main(int argc, const char** argv)
{
   ConstructorCounter a, b, c, d;
   std::cout << ConstructorCounter::num_constructed() << std::endl;
   ConstructorCounter e(a);
   std::cout << ConstructorCounter::num_constructed() << std::endl;
   return 0;
}