"is private within this context" is being thrown for function which should not be private (GCC 5.3.0, C++11)
18,913
By default class members are private, even you use private
access specifier later, Your code is like :
template<class T>
class Queue{
Queue(); //Implicitly private
Queue(T item); //Implicitly private
private: //explicit private
Link<T>* head;
Link<T>* end;
int length;
};
so you need to make constructors public :
template<class T>
class Queue{
public:
Queue();
Queue(T item);
private:
Link<T>* head;
Link<T>* end;
int length;
};
Same goes for Link<T>
class template.
Author by
ceaston7
Updated on June 05, 2022Comments
-
ceaston7 almost 2 years
I am attempting to create a queue, which requires the creation of another object stored in the queue. The errors are
binary.cpp: In function ‘int main()’: binary.cpp:183:1: error: ‘Queue<T>::Queue(T) [with T = binary<std::basic_string<char> >*]’ is private Queue<T>::Queue(T item){ ^ binary.cpp:286:65: error: within this context Queue<binary<string>*>* queue = new Queue<binary<string>*>(tree); ^
and
binary.cpp: In instantiation of ‘Queue<T>::Queue(T) [with T = binary<std::basic_string<char> >*]’: binary.cpp:286:65: required from here binary.cpp:132:1: error: ‘Link<T>::Link(T) [with T = binary<std::basic_string<char> >*]’ is private Link<T>::Link(T item){ ^ binary.cpp:184:7: error: within this context head = new Link<T>(item);
The first is the instantiation of the Queue, and the second comes from the Queue's constructor, which is called in the instantiation line in the first error. The important declarations and definitions are:
template<class T> class Link{ Link(T item); private: T content; Link<T>* next; }; template<class T> Link<T>::Link(T item){ content = item; next = NULL; } template<class T> class Queue{ Queue(); Queue(T item); private: Link<T>* head; Link<T>* end; int length; }; template<class T> Queue<T>::Queue(T item){ head = new Link<T>(item); end = head; length = 1; }
The Link class is declared and defined before the Queue class, and both are declared and defined before they are used in code. Thank you for your time.