I have a constructor attempting to initialize a field in a base class. The compiler complains. The field is protected, so derived classes should have access.
//The base class:
class BaseClass
{
public:
BaseClass(std::string);
BaseClass(const BaseClass& orig);
virtual ~BaseClass();
const std::string GetData() const;
void SetData(const std::string& data);
protected:
BaseClass();
std::string m_data;
};
BaseClass::BaseClass(const std::string data) : m_data(data) { }
BaseClass::BaseClass() { }
BaseClass::BaseClass(const BaseClass& orig) { }
BaseClass::~BaseClass() { }
void BaseClass::SetData(const std::string& data)
{
m_data = data;
}
const std::string BaseClass::GetData() const
{
return m_data;
}
//The derived class:
class DerivedClass : public BaseClass
{
public:
DerivedClass(std::string data);
DerivedClass(const DerivedClass& orig);
virtual ~DerivedClass();
private:
};
DerivedClass::DerivedClass(std::string data) : m_data(data) { } //ERROR HERE
DerivedClass::DerivedClass(const DerivedClass& orig) { }
DerivedClass::~DerivedClass() { }
//The compiler error
DerivedClass.cpp:3: error: class ‘DerivedClass’ does not have any field named ‘m_data’
Any help is greatly appreciated. Thank you in advance.
You cannot initialize m_data in the derived class constructor but instead pass it as an argument to the base class constructor.
That is: DerivedClass::DerivedClass(std::string data) : BaseClass(data) { }