No match for call to function C++

Question

I'm trying to program a raytracer and I cant compile my program because of the following error:

src\util\Ray.cpp: In constructor 'Ray::Ray()': src\util\Ray.cpp:8:17: error: no match for call to '(Vector3D) (double, double, double)'
o(0.0, 0.0, 0.0); ^ makefile.mak:31: recipe for target 'Ray.o' failed mingw32-make: *** [Ray.o] Error 1

This is the code:

//Vector3D.h
#ifndef __VECTOR3D__
#define __VECTOR3D__

class Vector3D{
    public: 

        float x;
        float y;
        float z;

    public: 

        Vector3D(void);
        Vector3D(const float&, const float&, const float&);
        Vector3D(const Vector3D& obj);
};

#endif



//Vector3D.cpp
#include <iostream>

#include "Vector3D.h"

using namespace std;

Vector3D::Vector3D(void){
    x       = 0.0;
    y       = 0.0;
    z       = 0.0;
}

Vector3D::Vector3D(const float &p_x, const float &p_y, const float &p_z){
    x       = p_x;
    y       = p_y;
    z       = p_z;
}

Vector3D::Vector3D(const Vector3D& obj){
    x       = obj.x;
    y       = obj.y;
    z       = obj.z;
}



//Ray.h
#ifndef __RAY__
#define __RAY__

#include "Vector3D.h"

class Ray{
    public:

        Vector3D o;
        Vector3D d;

    public: 

        Ray(void);
};

#endif



//Ray.cpp
#include "Ray.h"

Ray::Ray(void){
    o(0.0, 0.0, 0.0);
}

I cant figure out whats wrong here, could someone explain?

Maybe `this->o = Vector3D(0.0, 0.0, 0.0);` instead of `o(0.0, 0.0, 0.0);`? — DimChtz, Aug 22 '16 at 18:54
Works, thank you! Would you care to elaborate why i have to do it this way? — krbu, Aug 22 '16 at 18:57
OT: Your include guards are illegal. https://stackoverflow.com/questions/228783/what-are-the-rules-about-using-an-underscore-in-a-c-identifier — Baum mit Augen, Aug 22 '16 at 18:57
`o(0.0, 0.0, 0.0);` is calling of an `operator()` overload on `Vector3D` object... — W.F., Aug 22 '16 at 18:58

score 1 · Accepted Answer · answered Aug 22 '16 at 19:03

By the time you get to your constructor's body, all members have already been initialized. This means that in your Ray constructor:

Ray::Ray(void){
    o(0.0, 0.0, 0.0);
}

the line o(0.0, 0.0, 0.0); is equivalent to o.operator()(0.0, 0.0, 0.0).

To call a non-default constructor for a member, you need to use an initialization list:

Ray::Ray() : o(0.0, 0.0, 0.0) {
    // note the body of the constructor is now empty
}

No match for call to function C++

1 Answers1