C++ passing an array of classes

C++ passing an array of classes

Can anybody help me with the syntax of passing an array of classes to
another class. The syntax of passing an array of classes to another class
has got me beaten. class line tries to be initialised by an array of
points, but the prototype does not match.
#include <iostream>
using namespace std;
class point {
public:
point() {}
point(int x, int y) : X(x), Y(y) {}
void setXY(int x, int y) { X = x; Y = y; }
int getX() { return X; }
int getY() { return Y; }
private:
int X, Y;
};
class line {
public:
line(point *points, int); // Problem line.
private:
point *coords;
int numpoints;
};
int main() {
point points[3];
points[0].setXY(3, 5);
points[1].setXY(7, 9);
points[2].setXY(1, 6);
line l(points, 3); // Problem line.
return 0;
}
Error message: cygdrive/c/Tmp/cc4mAXRG.o:a.cpp:(.text+0xa7): undefined
reference to `line::line(point*, int)'