C++

adragons

I'm making a template class called Container with only one problem.

part of the assignments requirement is that I have to have a function that will print the contents of the class.

The other part is that it must work with a structure.

I am unsure as to how I should get the print function to show the contents of a structure...

nightice

are you printing any arbitrary class/structure or do you know beforehand what's inside?

adragons

I know whats inside:
eg

struct Location{
string street;
string country;
};

Location place;
place.street = "4th";
place.country = "Canada";

nightice

as long as they're publically accessible just access them like a normal struct/class member:

printf(place.street);
printf(place.country);
/* of course, the standard streams (i.e. cout) will work */

adragons

I think you missed this part
"I have to have a function that will print the contents of the class. "

like so:

template <class TYPE>
void Container<TYPE>::PrintContainer(void)
{
	cout << "Content: \n";
	for(int i = 0; i < _Index; i++)
	{
		cout << setw(15) << "arry[" << i << "]: " << setw(15) << arry[i] << endl;
	}

}

This method works for any non-object variable type (numbers, chars, strings) but not for a struct.

I don't know of anyway to test a variable to see wether it is an object/struct other than trying to access one of its attributes, which will cause compile errors when used with non-objects.

nightice

there's no automatic way to access a struct, you need to work on each individual element:

cout << setw(15) << "place.street: " place.street << endl;

c++ has no way of knowing what's in a struct. structs are, at their simplest, just a way for the compiler to calculate proper pointer offsets, it doesn't keep track of what's inside, just the size of the elements.

adragons

Hm, I guess it would help if I understood pointers more.

I'm no stranger to OOP, and I understand C++ cannot automatically know whats in a struct.

Is there a way to determine if a variable is a struct?

like for an array you can do:

sizeof array / sizeof array[0];

and for a struct you can do:

sizeof location / sizeof location.here;

but this wont compile because of the template TYPE not always being a struct.

nightice

Hmm, that's an interesting one...unfortunately, I do C more than C++, so I have little experience in templates. You might want to try asking someplace like here.