Question

I need to sort my custom class based on the std struct tm object. I would like to know if I am approaching this correctly and ask for suggestions for the comparison function. Originally, I was converting each std::tm member to some base number (like Ticks in .NET DateTime), but I thought that might be excessive.

I don’t have to use a list, but I do have to use a Container<MyClass*>. I would prefer the list, though. This is my custom class:

class MyClass
{
public:
  std::tm _datetime;
  static bool ComparePointers(MyClass*& lhs, MyClass*& rhs);
};

bool MyClass::ComparePointers(MyClass*& lhs, MyClass*& rhs)
{
  // ??
}

This is my main function:

int main()
{
   std::list<MyClass*> classes;
   MyClass* class_1 = new MyClass();  classes.push_back(class_1);
   MyClass* class_2 = new MyClass();  classes.push_back(class_2);
   MyClass* class_3 = new MyClass();  classes.push_back(class_3);

   list.sort(MyClass::ComparePointers);
}

Answer 1

You can use mktime to convert a std::tm value to a time_t which can be compared.