We are trying to write a really simple class, for complex numbers jsut as an example, and we do not get very far...
Below is our 3 files.
complex2.h
#include<iostream>
#include<new>
template<class T>
class complex2
{
private:
T re, im; // real and imaginary part
public:
complex2();
complex2(T re_a =0.0, T im_a =0.0); //= 0.0 = 0.0
~complex2() {}
T Re () const;
T Im () const;
};
#endif // COMPLEX2_H
complex2.cpp
#include "complex2.h"
template<class T>
complex2<T>:: complex2 () {re = im = 0.0; }
template<class T>
complex2<T>:: complex2(T re_a, T im_a){re = re_a; im = im_a;}
template<class T> T complex2<T>:: Re() const { return re;}
template<class T> T complex2<T>:: Im() const {return im;}
main.cpp
#include <iostream>
#include<cmath>
#include"complex2.h"
using namespace std;
int main()
{
complex2<int> b(1, 2);//
cout << "Re b: "<< b.Re() << "Im b: "<< b.Im() << endl;
return 0;
}
Running the above from Qt, gives the error messages
/home...main.cpp:10: error: undefined reference to `complex2<int>::complex2(int, int)'
/home/.../main.cpp:11: error: undefined reference to `complex2<int>::Im() const'
/home/...main.cpp:11: error: undefined reference to `complex2<int>::Re() const'
:-1: error: collect2: error: ld returned 1 exit status
Does anybody see how we can make this work?
