Getting two errors E0289 and C2440 pointing at initialization of vector - vector

Question

I am getting these two errors when initializing vc below.
#include <iostream>
#include <complex>
#include <math>
#include <vector>
#include <limits>
#include <list>
#include <string>
class Vector {
private:
double* elem; // elem points to an array of sz doubles
int sz;
public:
Vector(int s) :elem{ new double [s] }, sz{ s } // constructor: acquire resources
{
for (int i = 0; i != s; ++i) elem[i] = 0; // initialize elements
~Vector() { delete[] elem; } // destructor: release resources
double& operator[](int i);
int size() const;
void push_back(double);
};
double& Vector::operator[](int i)
{
// TODO: insert return statement here
// added below since the funtion needs to return a double and
return elem[i];
}
int Vector::size() const
{
return sz;
}
void Vector::push_back(double)
{
}
class Container {
public:
virtual double& operator[](int) = 0; // pure virtual function
virtual int size() const = 0; // const member function (§3.2.1.1)
virtual ~Container() {} // destructor (§3.2.1.2)
};
// use function uses Container interface.
void use(Container& c)
{
const int sz = c.size();
for (int i=0; i!=sz; ++i)
cout << c[i] << '\n';
}
class Vector_container : public Container { // List_container implements Container
Vector v;
public:
Vector_container(int s) : v(s) {} // Vector of s elements
void ˜Vector_container() {}
double& operator[](int i) { return v[i]; }
int size() const { return v.size(); }
};
void main()
{
Vector_container vc = { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
use(vc)
}
I receive both errors pointing at this line Vector_container vc = { 1, 2, 3, 4, 5, 6, 7, 8, 9 }
Error E0289 is - no instance of constructor "Vector_container::Vector_container" matches the argument list
Error C2440 'initializing': cannot convert from 'initializer list' to 'Vector_container'

Answer 1

I was able to solve the issue by modifying the Vector_container and initializing using Initializer-list constructor below:
class Vector_container : public Container {
std::list<double> ld;
public:
Vector_container() { }
Vector_container(initializer_list<double> il) : ld{ il } {}
~Vector_container() {}
double& operator[](int i);
int size() const { return ld.size(); }
};
double& Vector_container::operator[](int i)
{
for (auto& x : ld) {
if (i == 0) return x;
--i;
}
}