Path: utzoo!attcan!uunet!yale!cmcl2!rna!kc
From: kc@rna.UUCP (Kaare Christian)
Newsgroups: comp.lang.c++
Subject: constructor calls constructor?
Keywords: constructors, this
Message-ID: <601@rna.UUCP>
Date: 26 May 89 14:02:38 GMT
Organization: Rockefeller University - Neurobiology
Lines: 36

A question, if you please.

I have a class that has several constructors.
	class X {
		...
	public:
		X();
		X(int n);

All of these constructors have some mundane chores that must be accomplished,
plus there are extra chores for those that take extra arguments. What I tried
to do was have the "parameter taking" constructors all call the
parameterless constructor. So, I had something like
	X::X(int n)
	{
		X();
		// the extra work
	}
This didn't work, the call to X() created a new object, it didn't
initialize the current object. (I guess this makes sense, 'cause a
statement like A=X() should create a new object.) Then I tried
	X::X(int n)
	{
		this->X();
		// the extra work here
	}
But this didn't pass muster, Zortech C++ complained that "X wasn't a member
of class X."

Is there a way for one constructor to call another, simply to have
some chores performed, while avoiding real construction? (I know I can
have all the constructors call some helper function, but that
seems too roundabout.)

Thanks,
Kaare Christian