Template problem

[david112]

Hi ,

Given the following code :

#include <iostream>
using namespace std;

template <class T>
void print (T obj1 = 0 , T obj2 = 0)
{
	cout << obj1 + obj2 << endl;
}

int main() {

	print();
	return 0;
}

I do not understand why the line "print();" won't compile , but the line
"print(3);" does.
Can you please explain ?
10x,Dave

[ModShop]

That is a template function. You need to pass a parameter for the compiler to know how to instantiate it, or you could explicitly pass the template parameter:

print<int>();

[Disch]

if you just say print(), then the compiler doesn't know what type you want for T.

If you say print(3), then the compiler can tell that you want T to be int, and therefore it can call the function.

Another way to say which type you want is to say so explicitly:

print<int>();

[david112]

But the template has default values of zero and zero , ain't that enough ?

10x

[quirkyusername]

No.

What is 'zero'? Zero can be assigned to an int, a bool, a pointer to any type...read a little about templates http://cplusplus.com/doc/tutorial/templates/