Path: utzoo!attcan!uunet!mcsun!tuvie!inst182
From: inst182@tuvie (Inst.f.Techn.Informatik)
Newsgroups: comp.lang.c++
Subject: calling (con|de)structors explicitly
Keywords: c++1.2, constructor
Message-ID: <1088@tuvie>
Date: 7 Feb 90 16:45:17 GMT
Organization: TU Vienna EDP-Center, Vienna, AUSTRIA
Lines: 55


I have a problem: I want to dynamically create an array of
a class as a member of another class. Now I cannot use the 
new operator, because the constructors of this class all
have at least one argument. Thus, I'd like to allocate the 
memory with malloc and call the constructor explicitly 
for each element. Can I do anything to make 
this legal:

class foo {

	/* something */
public:

	foo(int);
	~foo();
}

class bar { 
	/* something else */

public:

	bar(int,int);
	~bar();

}

bar::bar(int x, int y){

	foo	*help, *h2;

	help = (foo *) malloc (sizeof(foo)*x);

	for (h2 = help ; h2 < help +x ; h2++){
		h2->foo(y);
	}
}


One way would be to have a function that really dowes the initialization
and call this from the constructor. This function, I could also call
from the bar::bar() routine, but if I for example do not have the source
of foo, that will not be an alternative. *ANY* hints ?


				Thanx in advance,
					mike

       ____  ____
      /   / / / /   Michael K. Gschwind             mike@vlsivie.at
     /   / / / /    Institute for VLSI-Design       mike@vlsivie.uucp
     ---/           Technical University, Vienna 
       / 
   ___/