C++ Constructor inheritance no matching function

Question

I'm currently working on a project with several classes :

an abstract one : template <typename Elem> class Vector {...}
another abstract one : template <typename Elem> class AbsPolynom: virtual public Vector<Elem>
a inheritence from Vector : template <typename Elem> class Dvector: virtual public Vector<Elem>
and the last one : template <typename Elem> class Polynom: public AbsPolynom<Elem>, public Dvector<Elem>{

When I call Polynom, like this : Polynom<int> test(std::size_t(3),3,3);

I get this error :

In file included from Polynom.cpp:6:0,
                 from main2.cpp:4:
Polynom.hpp: In instantiation of ‘Polynom::Polynom(std::size_t, const Elem&, const int&) [with Elem = int; std::size_t = long unsigned int]’:
main2.cpp:10:41:   required from here
Polynom.hpp:14:105: error: no matching function for call to ‘Vector::Vector()’
   Polynom(std::size_t dim, const Elem& value, const int& degrees ): AbsPolynom(dim, value, degrees) {};

So here is my question : Why does it call this constructor from Vector? I always have a parameter but it initializes this class without parameters

Here are my Constructors :

Polynom :

Polynom(std::size_t dim, const Elem& value, const int& degrees ): AbsPolynom<Elem>(dim, value, degrees) {}; 

Polynom(std::size_t dim, const Elem& value, const int degrees[] ): AbsPolynom<Elem>(dim, value, degrees) {};

Polynom(std::size_t dim, const Elem values[], const int& degrees): AbsPolynom<Elem>(dim, values, degrees) {};   

Polynom(std::size_t dim, const Elem values[], const int degrees[]): AbsPolynom<Elem>(dim, values, degrees) {};

AbsPolynom :

explicit AbsPolynom(std::size_t, const Elem&, const int& );     
explicit AbsPolynom(std::size_t, const Elem&, const int [] );       
explicit AbsPolynom(std::size_t, const Elem [], const int& );   
explicit AbsPolynom(std::size_t, const Elem [], const int [] ); 

template <typename Elem>AbsPolynom<Elem>::AbsPolynom(std::size_t dim, const Elem& value, const int& degrees ): Vector<Elem>(dim, value), _degrees(new Elem[dim]),_polynomDegree(degrees)  {
    for (std::size_t i = 0; i < dim; ++i) _degrees[i]  = degrees;}

    template <typename Elem>AbsPolynom<Elem>::AbsPolynom(std::size_t dim, const Elem& value, const int degrees[] ): Vector<Elem>(dim, value), _degrees(new Elem[dim]),_polynomDegree(degrees[0])  {
    for (std::size_t i = 0; i < dim; ++i) _degrees[i]  = degrees[i];}


    template <typename Elem>AbsPolynom<Elem>:: AbsPolynom(std::size_t dim, const Elem values[], const int& degrees): Vector<Elem>(dim, values), _degrees(new Elem[dim]),_polynomDegree(degrees)  {
    for (std::size_t i = 0; i < dim; ++i) _degrees[i] = degrees;}

    template <typename Elem>AbsPolynom<Elem>::AbsPolynom(std::size_t dim, const Elem values[], const int degrees[]): Vector<Elem>(dim, values), _degrees(new Elem[dim]),_polynomDegree(degrees[0])  {
    for (std::size_t i = 0; i < dim; ++i) _degrees[i] = degrees[i];}

and Vector :

    explicit Vector(std::size_t dim, const Elem& elem);    
    explicit Vector(std::size_t, const Elem[] );

template <typename Elem>Vector<Elem>::Vector (std::size_t dim, const Elem& elem):_dim(dim), _values(new Elem[dim]) {
for (std::size_t i = 0; i < dim; ++i) _values[i] = elem;      }

template <typename Elem>Vector<Elem>::Vector ( std::size_t dim, const Elem elem[]):_dim(dim), _values(new Elem[dim]) {
for (std::size_t i = 0; i < dim; ++i) _values[i] = elem[i];
}

Please edit your question with a minimal reproducible example or SSCCE (Short, Self Contained, Correct Example) — NathanOliver
Does Vector have a parameterless constructor? Please show the signatures of Vector and Polynom constructors. — Zdeslav Vojkovic

Bo Persson Bo Persson · Accepted Answer · 2015-12-17T13:40:39

When you have virtual inheritance, the most derived class has to call the constructor for the virtual base class. There is only one copy, and it has to be called exactly once.

If not called, the compiler tries to call the default constructor (and fails if there is none).

C++ Constructor inheritance no matching function

1 Answers