在构造函数中要做什么(不做)

class Vector
{
public:
  Vector(): mSize(10), mData(new int[mSize]) {}
private:
  size_t mSize;
  int mData[];
};

class Vector
{
public:
  Vector(): mSize(0), mData(0) {}

  // first call to access element should grab memory

private:
  size_t mSize;
  int mData[];
};

// in the constructor
Setting::Setting()
{
  // connect
  // retrieve settings
  // close connection (wait, you used RAII right ?)
  // initialize object
}

// Builder method
Setting Setting::Build()
{
  // connect
  // retrieve settings

  Setting setting;
  // initialize object
  return setting;
}

class A
{
public:
    A(){ doA();} 
    virtual void doA(){};
}

class B : public A
{
public:
    virtual void doA(){ doB();};
    void doB(){};   
}


void testB()
{
    B b; // this WON'T call doB();
}

void doA();

class A
{
public: 
    void callAPolymorphicBehaviour()
    {
        doOverridenBehaviour(); 
    }

    virtual void doOverridenBehaviour()
    {
        doA();
    }

    void doA(){}
};

class B : public A
{
public:
    B()
    {
        callAPolymorphicBehaviour();
    }

    virtual void doOverridenBehaviour()
    {
        doB()
    }

    void doB(){}
};

void testB()
{
   B b; // this WILL call doB();
}

virtual doOverridenBehaviour()

• delete this
• RAII

RAII exception safety

void func() {
    MyFile f("myfile.dat");
    doSomething(f);
}

MyFile doSomething(f) f

• virtual

init()

class std::string begin() end() c_str()

What all to do in the constructor?

Constructors Must Be Code-Free