Don't Code Without Coffee

[George P]

I have some class code that had data members on the stack I was modifying to be constructed on the heap. Original (simplified) code:

#include <iostream>
#include <string>

using ushort_t = unsigned short;

class Human
{
private:
   std::string Name;
   ushort_t    Age;

public:
   // constructor
   Human();

   // destructor
   ~Human();

public:
   void SetName(std::string HumansName)  { Name = HumansName; }

   void SetAge(ushort_t HumansAge)       { Age = HumansAge; }

   void IntroduceSelf();
};

int main()
{
   Human FirstMan;
   FirstMan.SetName("Adam");
   FirstMan.SetAge(30);

   Human FirstWoman;
   FirstWoman.SetName("Eve");
   FirstWoman.SetAge(28);

   std::cout << '\n';

   FirstMan.IntroduceSelf();
   FirstWoman.IntroduceSelf();

   std::cout << '\n';
}


Human::Human()
{
   std::cout << "Constructing an instance of class Human\n";

   Name = "";
   Age  = 0;
}

Human::~Human()
{
   std::cout << "Destroying an instance of class Human\n";
}


inline void Human::IntroduceSelf()
{
   std::cout << "I am " + Name << ", and I am " << Age << " years old.\n";
}

So far so good, stack version compiled fine, ran great, less filling, etc.

After several botched attempts to change the Age data member to be on the heap I finally got a version that compiled, and ran. Somewhat. Age was being reported as 0. *scratches head*

I had changed SetAge to this:
void SetAge(ushort_t HumansAge) { Age = &HumansAge; }

Win 10 reports non-critical errors with programs, and every time I ran the .exe another error report was generated.

OK, I definitely needed some coffee while I tried to figure out what was going wrong.

Two cups later, *BOING!*

void SetAge(ushort_t HumansAge) { *Age = HumansAge; }

The moral is: No Coffee, Make Stupid Mistakes

I know there are other issues with the code, such as the constness of the getter.

[jlb]

Where are you allocating the memory for Age?

[Ganado]

Why are you (presumably) allocating heap memory for Age?

[George P]

Where are you allocating the memory for Age?

In the ctor, of course, and deleting it in the dtor. Naturally.

Why are you (presumably) allocating heap memory for Age?

I was bored and fiddling with some old code for shits and giggles. Without any coffee.

I didn't think I needed to show ALL of the fixed code for a rant, I see I was wrong. Again.

The final (simplified) version:

#include <iostream>
#include <string>

using ushort_t = unsigned short;

class Human
{
private:
   std::string Name;
   ushort_t*   Age;

public:
    Human();

   // destructor
   ~Human();

public:
   void SetName(std::string HumansName)  { Name = HumansName; }

   void SetAge(ushort_t HumansAge)       { *Age = HumansAge; }

   void IntroduceSelf();
};

int main()
{
   Human FirstMan;
   FirstMan.SetName("Adam");
   FirstMan.SetAge(30);

   Human FirstWoman;
   FirstWoman.SetName("Eve");
   FirstWoman.SetAge(28);

   std::cout << '\n';

   FirstMan.IntroduceSelf();
   FirstWoman.IntroduceSelf();

   std::cout << '\n';
}


Human::Human()
{
   std::cout << "Constructing an instance of class Human\n";

   Name = "";
   Age  = new ushort_t(0);
}

Human::~Human()
{
   std::cout << "Destroying an instance of class Human\n";

   delete Age;
}


inline void Human::IntroduceSelf()
{
   std::cout << "I am " + Name << ", and I am " << *Age << " years old.\n";
}

Not production level code by any means, never intended it to be. This is just an training exercise example of making a very stupid mistake.