CODEWITHSUNDEEP
c++
p.chives
p.chives

Reputation: 125

typedef statement inside a template class

I'm trying to convert one of my files into a template but the typedef statement is giving me some trouble. The error I'm getting is:

error: declaration of ‘typedef typename LinkedList<value_type>::value_type Queue<value_type>::value_type’ shadows template parameter

I'm confused about how to use typedef in this situation because if I 'un-template' the file it considers value_type undefined for the other classes referenced in this file.

My code:

#include <cstdlib>
#include "LinkedList.h"
#include "Node.h"
template <typename value_type>
class Queue
{
public:
typedef typename LinkedList<value_type>::value_type value_type;

Queue();
void enqueue(const value_type& obj);
value_type dequeue();

value_type& front();

bool is_empty() const;
int size() const;

private:
LinkedList<value_type> data;
int used;
};

Upvotes: 1

Views: 75

Answers (1)

Matthieu Brucher
Matthieu Brucher

Reputation: 22023

Your issue is that value_type is already a known type, it's your template parameter.

You can't have anything else redefining it, especially to a different type.

I had the same "issue" because I wanted another class to retrieve the type used for the template like you did, in that case, rename the template argument to something else.

Upvotes: 5

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