Passing variables to a constructor with multiple inheritance - c++

Question

I am having problems passing up two pieces of data through my classes, ID and Name specificly. I understand that you cannot call the base class constructor up without going through the previous parent classes but I am struggiling to fiugure out why this is not working, do I need constructors all the way up or can I just add it on at the end of my class creation like the base class?
Thanks in advance.
class CEmployee
{
private:
char m_name[30];
char m_id[30];
//virtual float Pay() { return 0;}; // virtual function
virtual float Pay() = 0; // pure virtual function
public:
CEmployee(char name[], char id[])
{
strcpy_s(m_name, name);
strcpy_s(m_id, id);
}
CEmployee()
{
strcpy_s(m_name, "");
strcpy_s(m_id, "");
}
void PrintCheck()
{
cout << m_name << " " << Pay() << endl;
}
};
class CFulltimeEmployee : public CEmployee
{
protected:
static float m_benefitcost;
public:
CFulltimeEmployee()
{
}
CFulltimeEmployee(char name[], char id[]) : CEmployee (name, id)
{
m_benefitcost = 100;
}
};
float CFulltimeEmployee::m_benefitcost = 100;
class CHourlyFTEmployee : public CFulltimeEmployee
{
private:
float m_rate;
float m_hours;
public:
CHourlyFTEmployee()
{
}
CHourlyFTEmployee(const char name[], const char id[], float rate, float hours) : CFulltimeEmployee
(name, id)
{
m_rate = rate;
m_hours = hours;
}
float Pay()
{
return m_rate * m_hours - m_benefitcost;
}
};
Errors
Error (active) E0289 no instance of constructor "CFulltimeEmployee::CFulltimeEmployee" matches the argument list
Error C2664 'CFulltimeEmployee::CFulltimeEmployee(char [],char [])': cannot convert argument 1 from 'const char []' to 'char []' Project9

Answer 1

Writing a minimal reproducible example really isn't that hard; you remove whatever isn't needed while still demonstrating the problem. In this case, it might be:
class CEmployee
{
char m_name[30];
char m_id[30];
virtual float Pay() = 0; // pure virtual function
public:
CEmployee(char name[], char id[])
{
strcpy_s(m_name, name);
strcpy_s(m_id, id);
}
};
struct CFulltimeEmployee : public CEmployee
{
CFulltimeEmployee(char name[], char id[]) : CEmployee(name, id) { }
};
struct CHourlyFTEmployee : public CFulltimeEmployee
{
CHourlyFTEmployee(const char name[], const char id[]) : CFulltimeEmployee(name, id) { }
float Pay() override { return 0.0; }
};
In particular, notice that none of m_benefitcost, m_rate or m_hours are needed; nor is PrintCheck(). (class is private by default while struct is public; this also helps to reduce noise.)
Once you've done that, it's very easy to see the problem the compiler is complaining about
error C2664: 'CFulltimeEmployee::CFulltimeEmployee(char [],char [])': cannot convert argument 1 from 'const char []' to 'char []'
In CHourlyFTEmployee, you've written const char name[] (and const char id[]); but the base class (CFulltimeEmployee) is char name[]—no const. Data that is const can't "easily" be assigned to non-const data; the "fix" is straight-forward: remove the const:
CHourlyFTEmployee(char name[], char id[]) : CFulltimeEmployee(name, id) { }`
The sample still has other issues, but it sounds like you're stuck with the existing CEmployee base class.
An even better solution is to hide as much of the legacy CEmployee class as possible; maybe by introducing another class CEmployeeNew (or CEmployee2); that might look like:
struct CEmployeeNew : public CEmployee
{
CEmployeeNew(const std::string& name, const std::string& id) :
CEmployee(const_cast<char*>(name.c_str()), const_cast<char*>(id.c_str())) { }
};