References and pointers in setters and getters. Need example

Question

I've been getting errors all day when I tried to use return reference or pointer in c++. Please tell me what should I change in code below to return Config class members by reference or pointer.

#include <cstdlib>
#include <iostream>

using namespace std;

class JustExample {
    public:
        string someText;
        JustExample() {
              someText = "blablabla";
        }
};

class Config
{
    public:
        Config();
        string getResourceDir() const;
        JustExample getExmp() { return exmp; }
        void setResourceDir(const string& dir);
        void setExmp(JustExample example) { exmp = example; }
    private:
        JustExample exmp;
        string res_dir;
};

Config::Config() { 
    res_dir = "class value";
}
string Config::getResourceDir() const { return res_dir; }
void Config::setResourceDir(const string& dir) { res_dir = dir; }

int main(int argc, char *argv[])
{
    Config cfg;
    cout << cfg.getResourceDir() << endl;
    cfg.setResourceDir("changed");
    cout << cfg.getResourceDir() << endl;

    cout << cfg.getExmp().someText << endl;

    system("PAUSE");
    return EXIT_SUCCESS;
}

Bonus question. Why can't I initialize variables after their declaration but have to assign their value in class constructor instead or I get an error.

8 D:\projects\dev-cpp test\main.cpp ISO C++ forbids initialization of member `someText' 
8 D:\projects\dev-cpp test\main.cpp making `someText' static 
8 D:\projects\dev-cpp test\main.cpp invalid in-class initialization of static data member of non-integral type `std::string' 
 D:\projects\dev-cpp test\main.cpp In function `int main(int, char**)': 
38 D:\projects\dev-cpp test\main.cpp 'class JustExample' has no member named 'someText' 
 D:\projects\dev-cpp test\Makefile.win [Build Error]  [main.o] Error 1

"Why can't I initialize variables after their declaration?" -- because C didn't allow that for struct members, and C++ didn't add it until much much later. Even initialization of static integral members wasn't available until C++03, and the brace-or-initializer-list for non-static members needs at least C++11, which your compiler may only partially support. — Ben Voigt
Does it not work to do this? JustExample& /* << ADDED THERE */ getExmp() { return exmp; } ? — Ben Voigt
I'm assuming that those errormessages come from code you didn't show which has string someText = "blablabla"; as a class member ? — M.M
You should really post two separate questions as the problem with JustExample is entirely different to the question about Config's getter/setters — M.M
@MattMcNabb: Yeah you are probably right but using visual studio is a pain for me especially since I'm just starting with c++. I wrote this quick snippet in Dev C++ just to quickly demonstrate what gives me a little headache and encountered a problem with initialization that threw me off a bit. ~Thanks — sebastian_t

Unknown Unknown · Accepted Answer · 2015-02-10T00:10:58

The code you provide compiles with clang on mac OS X with no error. But I don't see where do you return reference or pointer, in Config you can do this:

class Config
{
    public:
        Config();
        const string& getResourceDir() const;
        const JustExample& getExmp() { return exmp; }
        void setResourceDir(const string& dir);
        void setExmp(const JustExample& example) { exmp = example; }
    private:
        JustExample exmp;
        string res_dir;
};

return by pointer is similar, just replace & with *, although it may be better to return reference in this case.

References and pointers in setters and getters. Need example

2 Answers