Thread: Need help with "primary expression" error

Hi everyone. I pretty new to C/C++. Heres my code:

Code:

#include "Environment.h"

int Environment :: nExist = 0;
int Environment :: nCreated = 0;

Environment :: Environment(void){
        serNo = ++nCreated;
        nExist++;

        char buffer[100];
        sprintf(buffer, "Environment%d", serNo);
        label = new char[strlen(buffer) + 1];
        strcpy(label, buffer);
        return;
}//Environment :: Environment(void)

Code:

#ifndef SIMULATION_H
#define SIMULATION_H

#include "Environment.cpp"

using namespace std;

class Simulation {
        private:
        Environment env;
        int serNo;
        static int nExist, nCreated;

        public:
        Simulation(void);
        Simulation(const Environment *);
Simulation(const Simulation&);
        ~Simulation();

        const Simulation & operator = (const Simulation&);

        void print(void) const;
};

Code:

#include "Simulation.h"

int Simulation :: nExist = 0;
int Simulation :: nCreated = 0;

Simulation :: Simulation(void){
        serNo = ++nCreated;
        nExist++;
        env = new Environment(void);

        return;
}//Simulation :: Simulation(void)

Heres the Error:

Code:

Simulation.cpp: In constructor `Simulation::Simulation()':
Simulation.cpp:9: error: expected primary-expression before "void"

Any help would be greatly appreciated

O.K. I changed it to #include "Environment.h".
Still getting the same error though.
Any other thoughts?

Code:

env = new Environment(void);

don't use void when calling a function.

Thanks. I took out the void

Code:

#include "Simulation.h"

int Simulation :: nExist = 0;
int Simulation :: nCreated = 0;

Simulation :: Simulation(void){
        serNo = ++nCreated;
        nExist++;
        env = new Environment();

        return;
}//Simulation :: Simulation(void)

and now I've got this error.

Code:

Simulation.cpp: In constructor `Simulation::Simulation()':
Simulation.cpp:9: error: no match for 'operator=' in '((Simulation*)this)->Simulation::env = (((Environment*)operator new(8u)), (<anonymous>->Environment::Environment(), <anonymous>))'
Environment.h:22: note: candidates are: const Environment& Environment::operator=(const Environment&)

new returns a pointer.

Code:

Environment *env;

make sure to delete it in your destructor.

That makes sense. I still have one more error:

Code:

Simulation.cpp: In constructor `Simulation::Simulation()':
Simulation.cpp:9: error: no match for 'operator*' in '*((Simulation*)this)->Simulation::env'

Code:

#ifndef SIMULATION_H
#define SIMULATION_H

#include "Environment.h"

using namespace std;

class Simulation {
        private:
        Environment *env;
        int serNo;
        static int nExist, nCreated;

        public:
        Simulation(void);
        Simulation(const Environment *);
Simulation(const Simulation&);
        ~Simulation();

        const Simulation & operator = (const Simulation&);

        void print(void) const;
};

Code:

#include "Simulation.h"

int Simulation :: nExist = 0;
int Simulation :: nCreated = 0;

Simulation :: Simulation(void){
        serNo = ++nCreated;
        nExist++;
        *env = new Environment();

        return;
}//Simulation :: Simulation(void)

Originally Posted by robwhit

new returns a pointer.

Code:

Environment *env;

make sure to delete it in your destructor.

I also want to ask, is there any particular reason the OP feels the Environment should be dynamically allocated? If the lifetime of the environment is always the same as the lifetime of the Simulation, it would probably be better to hold the Environment by value (i.e., don't "new" it).

This also relieves you of the responsibility of delete'ing it in the Simulation destructor, as well as having to write an assignment operator.