Thread: Issue with placements of includes.

I have wrote out a simple data structure and can't seem to figure out where to place the include statement for one of my classes. The compiler seems not to recognize me creating my object because I've placed it wrong. I'm in the process of debugging my code so there are many other errors which I'm still working on. If you would like to make a comment on things that's incorrect or better coding practice it is of course appreciated. However, the real reason I post this code is to correct the issue I've stated before.

element.h

Code:

#ifndef ELEMENT_H_INCLUDED
#define ELEMENT_H_INCLUDED

class Element{

    private:
        int number;
        Element *next = new Element(NULL);
        Element *prev = new Element(NULL);

    public:
        Element(int number); //Constructor
        ~Element();          //Destructor
        int getNumber();     //Return number
        void setNext(Element e);
        void setPrev(Element p);
        Element getPrev();
        Element getNext();

};
#endif // ELEMENT_H_INCLUDED

element.cpp

Code:

#include "Element.h"
#include <cstddef>


//Constructor
Element::Element(int number){
    this.number = number;
    this.next = NULL;
    this.prev = NULL;
}

~Element::Element(){
    std::cout << "Element Detroyed" << std::endl;
}

int Element::getNumber(){
    return this.number;
}

void Element::setNext(Element e){
    this.next = e;
}

void Element::setPrev(Element e){
    this.prev = e;
}

Element Element::getPrev(){
    return this.prev;
}

Element Element::getNext(){
    return this.next;
}

customstack.h

Code:

#ifndef CUSTOMSTACK_H_INCLUDED
#define CUSTOMSTACK_H_INCLUDED

class customstack{

    private:
        int size;
        Element *traverseElement = new Element(-1);

    public:
        customstack();  //Constructor
        ~customstack(); //Destructor
        void push(int number);
        int pop();
        int getSize();


};

#endif // CUSTOMSTACK_H_INCLUDED

customstack.cpp

Code:

#include "Element.h"
#include <cstddef>
#include "customstack.h"


//Constructor
customstack::customstack(){
    this.size = 0;
    this->traverseElement.setNext(NULL);
    this->traverseElement.setPrev(NULL);
}

~customstack::customstack(){
    //destroyed
}

void customstack::push(int number){
    Element *temp = new Element(number);
    temp->setPrev(traverseElement);
    temp->setNext(NULL);
    this->traverseElement.setNext(temp);
    this->traverseElement = temp;
    this.size++;
}

int customstack::pop(){
    int temp = this->traverseElement.getNumber();
    Element *t = new Element(NULL);
    t = this.traverseElement;
    this->traverseElement = this->traverseElement.getPrev();
    this->traverseElement.setNext(NULL);
    delete t;
    this.size--;
    return temp;
}

int customstack::getSize(){
    return this.size;
}

mainclient.cpp

Code:

#include <iostream>
#include <cstdlib>
#include <ctime>
#include "customstack.h"

using namespace std;

int main(){
    customstack *myStack = new customstack;
    myStack->push(45);
    srand(unsigned time(0));
    myStack->push(rand()%4000 + 1);
    for(int i = 0; i < 20; i++){
        myStack->push(rand() % 4000 + 1);
    }
    myStack->getSize();
    return 0;
}

compiler error

Code:

In file included from mainclient.cpp:4:0:
customstack.h:8:9: error: ‘Element’ does not name a type <~~ Error I need help with
mainclient.cpp: In function ‘int main()’:
mainclient.cpp:11:11: error: expected primary-expression before ‘unsigned’
In file included from Element.cpp:1:0:
Element.h:8:41: warning: non-static data member initializers only available with -std=c++11 or -std=gnu++11 [enabled by default]
Element.h:9:41: warning: non-static data member initializers only available with -std=c++11 or -std=gnu++11 [enabled by default]
Element.h:8:37: error: ‘NULL’ was not declared in this scope
Element.h:9:37: error: ‘NULL’ was not declared in this scope
Element.cpp: In constructor ‘Element::Element(int)’:
Element.cpp:7:10: error: request for member ‘number’ in ‘this’, which is of pointer type ‘Element* const’ (maybe you meant to use ‘->’ ?)
Element.cpp:8:10: error: request for member ‘next’ in ‘this’, which is of pointer type ‘Element* const’ (maybe you meant to use ‘->’ ?)
Element.cpp:9:10: error: request for member ‘prev’ in ‘this’, which is of pointer type ‘Element* const’ (maybe you meant to use ‘->’ ?)
Element.cpp: At global scope:
Element.cpp:12:1: error: invalid use of destructor ‘~Element’ as a type
Element.cpp: In member function ‘int Element::getNumber()’:
Element.cpp:17:17: error: request for member ‘number’ in ‘this’, which is of pointer type ‘Element* const’ (maybe you meant to use ‘->’ ?)
Element.cpp: In member function ‘void Element::setNext(Element)’:
Element.cpp:21:10: error: request for member ‘next’ in ‘this’, which is of pointer type ‘Element* const’ (maybe you meant to use ‘->’ ?)
Element.cpp: In member function ‘void Element::setPrev(Element)’:
Element.cpp:25:10: error: request for member ‘prev’ in ‘this’, which is of pointer type ‘Element* const’ (maybe you meant to use ‘->’ ?)
Element.cpp: In member function ‘Element Element::getPrev()’:
Element.cpp:29:17: error: request for member ‘prev’ in ‘this’, which is of pointer type ‘Element* const’ (maybe you meant to use ‘->’ ?)
Element.cpp: In member function ‘Element Element::getNext()’:
Element.cpp:33:17: error: request for member ‘next’ in ‘this’, which is of pointer type ‘Element* const’ (maybe you meant to use ‘->’ ?)
In file included from customstack.cpp:1:0:
Element.h:8:41: warning: non-static data member initializers only available with -std=c++11 or -std=gnu++11 [enabled by default]
Element.h:9:41: warning: non-static data member initializers only available with -std=c++11 or -std=gnu++11 [enabled by default]
Element.h:8:37: error: ‘NULL’ was not declared in this scope
Element.h:9:37: error: ‘NULL’ was not declared in this scope
In file included from customstack.cpp:3:0:
customstack.h:8:50: warning: non-static data member initializers only available with -std=c++11 or -std=gnu++11 [enabled by default]
customstack.cpp: In constructor ‘customstack::customstack()’:
customstack.cpp:8:10: error: request for member ‘size’ in ‘this’, which is of pointer type ‘customstack* const’ (maybe you meant to use ‘->’ ?)
customstack.cpp:9:27: error: request for member ‘setNext’ in ‘((customstack*)this)->customstack::traverseElement’, which is of pointer type ‘Element*’ (maybe you meant to use ‘->’ ?)
customstack.cpp:10:27: error: request for member ‘setPrev’ in ‘((customstack*)this)->customstack::traverseElement’, which is of pointer type ‘Element*’ (maybe you meant to use ‘->’ ?)
customstack.cpp: At global scope:
customstack.cpp:13:1: error: invalid use of destructor ‘~customstack’ as a type
customstack.cpp: In member function ‘void customstack::push(int)’:
customstack.cpp:19:34: error: invalid conversion from ‘Element*’ to ‘int’ [-fpermissive]
In file included from customstack.cpp:1:0:
Element.h:12:9: error:   initializing argument 1 of ‘Element::Element(int)’ [-fpermissive]
customstack.cpp:20:23: warning: passing NULL to non-pointer argument 1 of ‘Element::Element(int)’ [-Wconversion-null]
customstack.cpp:21:27: error: request for member ‘setNext’ in ‘((customstack*)this)->customstack::traverseElement’, which is of pointer type ‘Element*’ (maybe you meant to use ‘->’ ?)
customstack.cpp:23:10: error: request for member ‘size’ in ‘this’, which is of pointer type ‘customstack* const’ (maybe you meant to use ‘->’ ?)
customstack.cpp: In member function ‘int customstack::pop()’:
customstack.cpp:27:38: error: request for member ‘getNumber’ in ‘((customstack*)this)->customstack::traverseElement’, which is of pointer type ‘Element*’ (maybe you meant to use ‘->’ ?)
customstack.cpp:28:34: warning: passing NULL to non-pointer argument 1 of ‘Element::Element(int)’ [-Wconversion-null]
customstack.cpp:29:14: error: request for member ‘traverseElement’ in ‘this’, which is of pointer type ‘customstack* const’ (maybe you meant to use ‘->’ ?)
customstack.cpp:30:51: error: request for member ‘getPrev’ in ‘((customstack*)this)->customstack::traverseElement’, which is of pointer type ‘Element*’ (maybe you meant to use ‘->’ ?)
customstack.cpp:31:27: error: request for member ‘setNext’ in ‘((customstack*)this)->customstack::traverseElement’, which is of pointer type ‘Element*’ (maybe you meant to use ‘->’ ?)
customstack.cpp:33:10: error: request for member ‘size’ in ‘this’, which is of pointer type ‘customstack* const’ (maybe you meant to use ‘->’ ?)
customstack.cpp: In member function ‘int customstack::getSize()’:
customstack.cpp:38:17: error: request for member ‘size’ in ‘this’, which is of pointer type ‘customstack* const’ (maybe you meant to use ‘->’ ?)

Why can I declare an integer buy not instantiate an object?

Yeah that seems to be an issue I'm having now.

Code:

#include "Element.h"
#include <cstddef>
#include <iostream>


//Constructor
Element::Element(int number){
    this->number = number;
    Element *next = new Element(NULL);
    Element *prev = new Element(NULL);
}

Element::~Element(){
    std::cout << "Element Detroyed" << std::endl;
}

int Element::getNumber(){
    return this->number;
}

void Element::setNext(Element e){
    this->next = e;                                   //Element.cpp:22:12: error: ‘next’ was not declared in this scope
}

void Element::setPrev(Element e){
    this->prev = e;
}

Element Element::getPrev(){
    return this->prev;
}

Element Element::getNext(){
    return this->next;
}

So if 'this' is a pointer and 'next' is how do both get dereferenced.
Tried a few ways. Haven't figured it out yet.

Originally Posted by Elkvis

in setNext and setPrev, you're passing values to the functions, and expecting to assign them to pointers. That's not going to work. Make the function parameter a pointer in each case. Also, getNext and getPrev both return values. Change them to return pointers.

Thank you. After fixing there still seems to be a problem with getting to the "next" and "prev" pointer. "this" is a pointer so I have to dereference it and get to "next" with -> but "next" is also a pointer but if the function perameter that I am using is a pointer than I dont see a problem. However, now I'm getting an "next was not declared in this scope" error.

Code:

#include "Element.h"
#include <cstddef>
#include <iostream>


//Constructor
Element::Element(int number){
    this->number = number;
    Element* next = new Element(NULL);
    Element* prev = new Element(NULL);
}

Element::~Element(){
    std::cout << "Element Detroyed" << std::endl;
}

int Element::getNumber(){
    return this->number;
}

void Element::setNext(Element* e){
    this->next = e;
}

void Element::setPrev(Element* e){
    this->prev = e;
}

Element* Element::getPrev(){
    return this->prev;
}

Element* Element::getNext(){
    return this->next;
}

Thank all of you guys so much. It is much appreciated. I have everything working great. I am going to study up more on the differences between the dot operator and the arrow and how to properly use header files. I felt I understood however now I feel I need more clarification. I have fixed all errors in my code but running valgrind find some memory leaks but that is an easy fix. I would like to post all my corrections so I may feel like this thread is completed and solved but for some reason the "code" tags keep deleting when I press post and I get an error and suggestion about reading the rules and to use the code tags lol. I'll try to post it in a few hours. Thank you all again!!