Question

I have an iPhone project, in this I wanted to use c++ files. I created c++ file like below:

File->New File -> C/C++ files -> C++ File
and named it as ClassA.cpp

In ClassA.cpp

#include <iostream>

class ClassA
{
  public:
    int a, b;

    void add();

};

void ClassA::add()
{

//    printf("sdf");
}

in my viewController.mm file:

#import "ViewController.h"
#import "ClassA.cpp"
- (void)viewDidLoad
{
    ClassA a;
    a.add();



    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

I read some posts it says me to rename .m to .mm so I renamed all .m files to .mm
And added two linker flags

-cclib -lstdc++

But It gives the following error:

Answer 1

You need to split the C++ portion into a header file and a cpp file, otherwise the ClassA::add will be defined twice.

ClassA.h:

#include <iostream>

class ClassA
{
  public:
    int a, b;

    void add();

};

ClassA.cpp:

#include "ClassA.h"
void ClassA::add()
{

//    printf("sdf");


}

Your .mm file:

#import "ClassA.h"
... the rest of the file ...