Question

I’ve looked a lot, tried a bunch of things I found on stackoverflow and other websites but I still can’t figure out how to fix this…

Main C++ file : source.cpp

#include "sources.h"
#include "fft_windows.h"
...

source.h

#include "Array2D.h"
...

Array2D.h

#ifndef ARRAY2D_H_
#define ARRAY2D_H_

#include <cassert>
#include "Features.h"

template <class T> class Array2D{
...
};
#endif

Features.h

#ifndef FEATURES_H_
#define FEATURES_H_


#include <string>

using namespace std ;


class Features : public Array2D {
...
};
#endif

fft_window.h (function declarations that are defined in fft_window.cpp)

//#include "Array2D.h"
template <class T>class Array2D;

void random_example(unsigned int i, Array2D <double> &arr);
...

I’ve tried everything I found and for some reason I still get this error in Features.h on the class Features : public Array2D { line…

Any idea ?

Answer 1

First, Features.h needs to include Array2D.h, second you get an infinite include recursion with that, and third you need to specify the template parameter when inheriting from Array2D:

class Features : public Array2D<int> {
//                  example --- ^^^