Thread: Templates

I just wrote a very simple vector class using templates:

Code:

template <typename Type> class Vector
{
public:
    Type X;
    Type Y;
    Type Z;
};

But how do I define functions and constructors like Vector(Type, Type, Type)? I get compile errors whenever I try. Any help would be appreciated.

This gives an error message:

Vectors error LNK2019: unresolved external symbol "public: __thiscall Vector<float>::Vector<float>(void)" (??0?$Vector@M@@QAE@XZ) referenced in function _main

Start a new project with just the following code, see if that compiles. It should compile without any problems.

Code:

template <typename Type> class Vector {
public:
	Vector(Type,Type,Type);
	Type GetX();
private:
    Type X;
    Type Y;
    Type Z;
};

template <typename Type>
Vector<Type>::Vector(Type x, Type y, Type z) {
	X=x; Y=y; Z=z;
}		

template <typename Type>
Type Vector<Type>::GetX() { return X; }

#include <iostream>
using namespace std;

int main() {
	Vector<int> myVect(1,2,3);
	cout << myVect.GetX();
}

one thing to remember is that when you create a template class, most compilers will not let you put the function definitions in a separate .cpp file, everything will need to be in the header file.

Originally Posted by rockytriton

one thing to remember is that when you create a template class, most compilers will not let you put the function definitions in a separate .cpp file, everything will need to be in the header file.

Oh, so that's the problem. Thanks.