Operator overloading in pure virtual classes [closed] - c++

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Hi I'm tring to create something like wrapper class for primitive types but I'm stuck on this issue:
When I try to create interface and be able to use polymorphism with descendants
edit
I'm getting
function returning abstract class "Var" is not allowed:
function "Var::operator+" is a pure virtual
function function "Var::operator-" is a pure virtual function
function "Var::operator*" is a pure virtual function
function "Var::operator/" is a pure virtual function
Here is my code
class Var
{
public:
Var() { }
virtual Var operator+(Var b) = 0;
virtual Var operator-(Var b) = 0;
virtual Var operator*(Var b) = 0;
virtual Var operator/(Var b) = 0;
};
class Decimal : public Var
{
public:
Decimal(double a) { value = a; }
Decimal() : Decimal(0) { };
virtual Decimal operator+( Decimal b)
{
return value + b.value;
}
virtual Decimal operator-( Decimal b)
{
return value - b.value;
}
virtual Decimal operator*( Decimal b)
{
return value * b.value;
}
virtual Decimal operator/( Decimal b)
{
return value / b.value;
}
Decimal operator=(double val)
{
value = val;
}
private:
double value;
};
any solution to my problem?

Answer 1

I think you are going about this the wrong way. Try a template
template<class T>
class Var
{
public:
typedef T Type;
Var(const Type& value = Type()) : value(value) {}
friend Var operator+(const Var& left, const Var& right)
{
return Var(left.value + right.value);
}
private:
Type value;
};