Untitled

Check if instance exists and return reference in Singleton getInstance();
class Song {

private:
    Song song;
    Song();
    Song(Song const&); // don't implement
    void operator = (Song const&); //don't implement

public:
    static Song &getInstance();
}

Song(Song const&); // don't implement
    void operator = (Song const&); //don't implement

static S& getInstance()
{
    static S    instance; // Guaranteed to be destroyed.
                          // Instantiated on first use.
    return instance;
}

Song(Song const&) = delete;
void operator = (Song const&) = delete;

static S& getInstance()
{
    static S    instance; // Guaranteed to be destroyed.
                          // Instantiated on first use.
    return instance;
}

Song(Song const&);

Song a;
Song b = a; // calls copy constructor

void operator=(const Song&);

Song a;
Song b;
b = a; // calls assignment operator.

Song& operator=(const Song&);