Ambiguous class inheritance

Question

#include <iostream>
#include <cmath>
using namespace std;
class Tcirculo{
        float radio;
        float diametro;
        float area;
public:
        void carea(float r){radio= r; area=(M_PI*((r*r)));}
        float cdiam(float r) {diametro = 2*r; return diametro;}
        float getr(){return radio;}
        float getd(){return diametro;}
        float geta(){return area;}

};


class Trectangulo : public Tcirculo{
        float altura;
public:
        float calca(float h, float r){altura =h;
        float arearec = getd() * h; return arearec;}
};

class Tcilindro :  public Tcirculo ,Trectangulo{
        float xx,bb;
public:
        Tcilindro(float a, float b) {xx=a;bb=b;}
        float area_total();
};

float Tcilindro::area_total(){
        int area;
        area = ((2*((getd())))+calca(bb,xx));
        return area;
}
int main(int argc, char *argv[]) {

        return 0;
}

but the problem is :

warning: direct base 'Tcirculo' inaccessible in 'Tcilindro' due to ambiguity

In member function 'float Tcilindro::area_total()':

error: reference to 'geta' is ambiguous
error: candidates are: float Tcirculo::geta()
error:                 float Tcirculo::geta()
error: reference to 'geta' is ambiguous
error: candidates are: float Tcirculo::geta()
error:                 float Tcirculo::geta()

Answer 1

These problems because of multiply inheritance with same Base Class. In you example class Tcilindro inherits from Trectangulo and Tcirculo but Trectangulo already derived from Tcirculo and Tcilindro have double definition of same functions. You just need to omit Tcirculo class here to remove ambiguity of inherited functions.

Answer 2

There is no need to derive Tcilindro from Tcirculo, it is sufficient if you derive it from Trectangulo.