I've stumbled upon a problem and I can't seem to find any information on SO on how to solve it. I've created a generic Point class and I'd like to convert from one to another. However, the compiler is always giving me the same error.
template<typename T>class Point
{
private:
T m_x, m_y;
public:
Point(): m_x(1), m_y(1){}
Point(T x, T y): m_x(x), m_y(y){}
void scale(T k){
this->m_x *= k;
this->m_y *= k;
}
void add(Point<T> p){
this->m_x += p.getX();
this->m_y += p.getY();
}
T getX() const{
return this->m_x;
}
T getY() const{
return this->m_y;
}
void setX(T x){
this->m_x = x;
}
void setY(T y){
this->m_y = y;
}
template<class U>
void add(Point<U> p){
this->m_x += p.getX();
this->m_y += p.getY();
}
template<class U>
Point<U>& operator=(const Point<T>& p){
this->m_x = p.getX();
this->m_y = p.getY();
return *this;
}
};
typedef Point<int> Pointi;
typedef Point<float> Pointf;
typedef Point<double> Pointd;
int main(int argc, char** argv){
Pointi pi(1,7);
Pointd pd = pi;
return 0;
}
This is the error I have whenever I compile.
error: conversion from ‘Point<int>’ to non-scalar type ‘Point<double\o>’ requested Pointd pd = pi;
Often confused: Pointd pd = pi; is not calling the assignment operator! It is initialisation not assignment. You can add a constructor like this to make your code compile:
template <class U>
Point(const Point<U>& other) : m_x(other.getX()),m_y(other.getY()) {}