class template error

**Bingo90** · 04-06-2014

I got an array class and I'm getting this error:

Error 1 error C2953: 'Array2D' : class template has already been defined

Array2D.h

Code:

#include "Tools.h"
template <typename T>
class Array2D
{
    T** arr;
    int xSize;
    int ySize;


public:
    Array2D(int xSize, int ySize)
    {
        arr = Tools::allocateDynamicArray<T>(xSize, ySize);
        this->xSize = xSize;
        this->ySize = ySize;


        for(int i = 0; i<xSize; i++)
        {
            for(int j = 0; j<ySize; j++)
            {
                arr[i][j] = null;
            }
        }
    }
    int getXSize()
    {
        return xSize;
    }
    int getYSize()
    {
        return ySize;
    }
    T get(int i, int j)
    {
        return arr[i][j];
    }
    void set(int i, int j, T value)
    {
        arr[i][j] = value;
    }
    Array2D(void);
    ~Array2D(void);
};

Tools.h

Code:

#pragma once
class Tools
{
public:
    template <typename T>
    static T **allocateDynamicArray( int nRows, int nCols)
    {
        T **dynamicArray;


        dynamicArray = new T*[nRows];
        for( int i = 0 ; i < nRows ; i++ )
            dynamicArray[i] = new T [nCols];


        return dynamicArray;
    }
    static long generateRandomLong();
    static bool isPrime(int num);
    static int randomNumberRange(int min, int max);
};

How can I fix this?

**ZuK** · 04-06-2014

I'd put include guards around the code in Array2d.h.
Guess that #pragma once thingy does the same thing
Kurt

**Bingo90** · 04-06-2014

Ok didn't know this takes care of the template stuff too

**phantomotap** · 04-06-2014

O_o

You've gone from not knowing how to use static member variables to not knowing how to use headers to not knowing how to templates work in 24 hours?

You are so far outpacing your ability to learn that you'll burn out.

Until you burn out, you'll be back here every couple of hours because you've built such a shaky foundation.

You should stop trying whatever nonsense you are trying; you aren't going to learn what you are doing.

Soma

**Elysia** · 04-06-2014

While I will not comment on the whole "learning things" thingy, I wouldn't say it's a bad thing to spread out and try things. You may not remember all, but you will get to have fun and learn new experiences in the process. Don't call it an evil act.

Btw, your array class is leaking memory.

**phantomotap** · 04-06-2014

O_o

I can't count how many wonderful programmers, as in people who already know how to program using a different language, I've seen fail to learn C++ following exactly this path.

I will absolutely call building such a flimsy foundation as to guarantee failure idiotic unless failure is somehow the goal.

Evil is unrelated.

Soma

**Elysia** · 04-06-2014

Who says it is to professionally learn the language? If that was the case, then I would agree, but if it is not...? What if it is simply an act to try out and have fun? What if it is to get a feel of what the language can do?

**phantomotap** · 04-06-2014

Who says it is to professionally learn the language?

O_o

Professionalism, like evil, is unrelated.

What if it is to get a feel of what the language can do?

o_O

How many years had you already been programming in C++ a few months back when you said to me something to the effect "You are still better at this than me."?

With over a decade of experience in C++, I've yet to find those limits.

Soma

Thread: class template error

Thread Tools

Search Thread

Display

class template error

Similar Threads

Operator overloading for an inner class of a class template causes compilation error

Pointer to template class error

Template <class T1, class T2, class T3> error LNK2019

Template Class and C2059 Error

class template error