From:	cgg AT mundil DOT cs DOT mu DOT OZ DOT AU (Christopher Geoffrey GRINTON)
Subject:	C++ constructors for global vars
To:	djgpp AT sun DOT soe DOT clarkson DOT edu
Date:	Sun, 15 Jan 1995 17:01:49 +1100 (EDT)

Sorry if this message has appeared before on this list. I posted the question
a few days ago, but for a variety of reasons I suspect it didn't get 
through.

Anyway, I'm having a problem with the order in which constructors are
invoked for global C++ objects. I have two classes, say A and B, and one
global object for each class:


	class A {
	public:
		A() {constructor code;}
	};

	A a;

	class B {
	public:
		B() {do something with object a;}
	};

	B b;

Now, the problem is, I need the constructor for a to be invoked before the
constructor for b (since this constructor uses object a). This is complicated
by the fact that the objects are in different source files in an archive.

Is there any way that I can force the above ordering? I've tried changing the
order of the files in the archive, which I though might change the order in
which they were linked, but this didn't help.

I wrote a little test program to try and solve this problem, and found that
I had to link the object files in the _reverse_ order that I wanted the
constructor invoked. Unfortunately, ordering the files in the archive in
the reverse order didn't work :(

Just another comment about this. Do people think that the above kind of
code is bad programming style? (ie. having global objects, with a requirement
to have a certain ordering for the invokation of their constructors.) I do
have good reasons for doing it, but I just wondered what people thought.

Thanks for any ideas.
Chris					cgg AT mundil DOT cs DOT mu DOT oz DOT au

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