classes within classes

It seems that in my time away from C++, I've forgotten something that I should still know.

I have this class:

Code:

class cIPAddress
{
	public:
		cIPAddress(string IPAddress) {	IP=IPAddress; }
        private:
		string IP;
};

And I want to use it as a member of another class, calling the constructor for cIPAddress from within the constructor for the other class:

Code:

class cOtherClass
{
	public:
		cIPAddress ipaddress;
                cOtherClass(string ip){ipaddress(ip);}
};

Obviously, the code in the constructor cOtherClass is not the way to do it; what is?

You have to use an initializer list

Code:

class cOtherClass
{
  public:
    cIPAddress ipaddress;
    cOtherClass(const string& ip)
      : ipaddress(ip)
    {}
};

In fact, you should use the initializer list in both cases:

Code:

class cIPAddress
{
  public:
    cIPAddress(const string& IPAddress)
      : IP(IPAddress)
    {}
  private:
    string IP;
};