Derived Template Class Copy Constructor Problem

Sep 28, 2012 at 10:24am
Clark (10)
I'm having trouble with my copy constructor is a new derived class I've created. Relevant code is as follows (I can provide other code from my project as well, but I think the error should be contained here):

Derived Class Header:
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#ifndef NUMERICARRAY_HPP
#define NUMERICARRAY_HPP

#include "Array_H.hpp"

namespace CLARK{
namespace Containers{

template <class Type=T> class NumericArray: public Array<Type>
{
private:

public:
    NumericArray(); // default constructor
    NumericArray(const NumericArray<Type>& nap); // copy constructor

    ~NumericArray(); // destructor

};

}
}

#ifndef NUMERICARRAY_CPP
#include "NumericArray.cpp"
#endif

#endif


Derived Class Source:
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#ifndef NUMERICARRAY_CPP
#define NUMERICARRAY_CPP

#include "NumericArray_H.hpp"

namespace CLARK{
namespace Containers{

// Constructors and Destructors:
    template <class Type>
    NumericArray<Type>::NumericArray() : Array()
    { // default constructor
        cout << "Numeric Array constructor call (default)" << endl;
    }

    template <class Type>
    NumericArray<Type>::NumericArray(const NumericArray<Type>& nap) : Array<Type>(nap)
    {// copy constructor   
        cout << "Numeric Array constructor call (copy)" << endl;
    }

    template <class Type>
    NumericArray<Type>::~NumericArray()
    {// destructor
        cout << "Numeric Array destructor call" << endl;
    }

}
}
#endif NUMERICARRAY_CPP


Base Class Header:
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#ifndef ARRAY_HPP
#define ARRAY_HPP

namespace CLARK{
namespace Containers{

template <class Type=T> class Array
{
private:
	Type* m_data; // dynamic array of Type objects
	int m_size; // size of array

public:
	static int m_default_size; // default size

// Constructors and Destructors:
	Array(); // default constructor
	Array(const Array<Type>& ap); // copy constructor

	~Array(); //destructor
		
};

}
}


#ifndef ARRAY_CPP
#include "Array.cpp"
#endif

#endif



Base Class Source:
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#ifndef ARRAY_CPP
#define ARRAY_CPP

#include "Array_H.hpp"
#include "ArrayException_H.hpp"
#include "OutOfBoundsException_H.hpp"

namespace CLARK{
namespace Containers{

// Constructors and Destructors:
	template <class Type>
	int Array<Type>::m_default_size = 10;

	template <class Type>
	Array<Type>::Array()
	{// Default constructor
		m_size = m_default_size; // added this per Peter87's post below
		m_data = new Type[m_default_size];
		cout << "Array constructor call (default)" << endl;
	}

	template <class Type>
	Array<Type>::Array(const Array<Type>& ap)
	{// Copy constructor
		m_size = ap.m_size;
		m_data = new Type[m_size];
		int i;
		for (i = 0; i < m_size; i++)
		{
			m_data[i] = (ap).m_data[i];
		}
		cout << "Array constructor call (copy)" << endl;
	}

	template <class Type>
	Array<Type>::~Array()
	{// Destructor
		delete []m_data;		
		cout << "Array destructor call" << endl;;
	}

}
}

#endif ARRAY_CPP



Test Program:
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#include "Array_H.hpp"
#include "NumericArray_H.hpp"
#include "ArrayException_H.hpp"
#include "OutOfBoundsException_H.hpp"

using namespace CLARK::Containers;
using namespace CLARK::CAD;

int main()
{

    try
    {

    NumericArray<int> intArray1;
    NumericArray<int> intArray2(intArray1);

    return 0;

    }

    catch(ArrayException& err)
    {
        cout << err.GetMessage() << endl;
    }
}
Edit & run on cpp.sh


The build completes successfully, but the command window hangs when it gets to the NumericArray copy. It looks like this:

Array constructor call (default)
Numeric Array constructor call (default)
_ [flashing cursor here. Windows never kills it.]


What am I missing here?

Thanks!
Last edited on Sep 28, 2012 at 3:05pm
Sep 28, 2012 at 10:59am
Peter87 (11251)
You forgot to initialize m_size in the default Array constructor.
Sep 28, 2012 at 11:10am
Clark (10)
Actually, I recently implemented this m_default_size, so I took out the m_size initialization from the Array constructor. Anyway, per your suggestion, I just changed the default Array constructor to this:

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	template <class Type>
	int Array<Type>::m_default_size = 10;

	template <class Type>
	Array<Type>::Array()
	{// Default constructor
		m_size = m_default_size;
		m_data = new Type[m_default_size];
		cout << "Array constructor call (default)" << endl;
	}


but I'm still receiving the same error. I don't think it's necessary to initialize m_size in the default constructor anymore, is it? Also, it seems to me that the default constructor is working fine. Perhaps I'm missing something else or misunderstanding?

Thanks.
Last edited on Sep 28, 2012 at 11:11am
Sep 28, 2012 at 11:21am
Peter87 (11251)
You need to initialize m_size, because it will be used in the copy constructor of intArray2 to set the size correctly.
Sep 28, 2012 at 11:24am
Clark (10)
Would the code is my last post be sufficient? Thanks!
Sep 28, 2012 at 11:32am
Clark (10)
I also tried simply doing this:

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	template <class Type>
	int Array<Type>::m_default_size = 10;

	template <class Type>
	Array<Type>::Array()
	{// Default constructor
		m_size = 10;
		m_data = new Type[m_default_size];
		cout << "Array constructor call (default)" << endl;
	}


but that didn't solve the problem either. Thanks.
Last edited on Sep 28, 2012 at 11:33am
Sep 28, 2012 at 12:37pm
Peter87 (11251)
Would the code is my last post be sufficient? Thanks!
Yes, it should fix that problem. There could be other problems.
Sep 28, 2012 at 3:06pm
Clark (10)
Actually, that did fix it! I forgot to rebuild the solution after that fix. Thanks!!!
Last edited on Sep 28, 2012 at 3:10pm
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