Very basic inheritance: error: expected class-name before ‘{’ token

Question

I'm trying to learn c++ and I've stumbled upon a error while trying to figuring out inheritance.

Compiling: daughter.cpp In file included from /home/jonas/kodning/testing/daughter.cpp:1: /home/jonas/kodning/testing/daughter.h:6: error: expected class-name before ‘{’ token Process terminated with status 1 (0 minutes, 0 seconds) 1 errors, 0 warnings

My files: main.cpp:

#include "mother.h" #include "daughter.h" #include <iostream> using namespace std;  int main() {     cout << "Hello world!" << endl;     mother mom;     mom.saywhat();     return 0; } 

mother.cpp:

#include "mother.h" #include "daughter.h"  #include <iostream>  using namespace std;   mother::mother() {     //ctor }   void mother::saywhat() {      cout << "WHAAAAAAT" << endl;   } 

mother.h:

#ifndef MOTHER_H #define MOTHER_H   class mother {     public:         mother();         void saywhat();     protected:     private: };  #endif // MOTHER_H 

daughter.h:

#ifndef DAUGHTER_H #define DAUGHTER_H   class daughter: public mother {     public:         daughter();     protected:     private: };  #endif // DAUGHTER_H 

and daughter.cpp:

#include "daughter.h" #include "mother.h"  #include <iostream>  using namespace std;   daughter::daughter() {     //ctor } 

What I want to do is to let daughter inherit everything public from the mother class (=saywhat()). What am I doing wrong?

Answer 1

You forgot to include mother.h here:

#ifndef DAUGHTER_H #define DAUGHTER_H  #include "mother.h"  //<--- this line is added by me.      class daughter: public mother {     public:         daughter();     protected:     private: };  #endif // DAUGHTER_H 

You need to include this header, because daughter is derived from mother. So the compiler needs to know the definition of mother.