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From: pal@xanadu.wpd.sgi.com (Anil Pal)
Newsgroups: comp.lang.c++
Subject: Re: Need `set before used' warning
Keywords: c++, warning
Message-ID: <1990Sep27.001259.25809@relay.wpd.sgi.com>
Date: 27 Sep 90 00:12:59 GMT
References: <2@mtnmath.UUCP>
Sender: news@relay.wpd.sgi.com ( CNews Account )
Reply-To: pal@sgi.com
Organization: Silicon Graphics, Inc.
Lines: 26

In article <2@mtnmath.UUCP>, paul@mtnmath.UUCP (paul) writes:
|> class Example {
|> 	char * Point ;
|> public:
|> 	Example(char * point) {point=Point;} // NOTE inverted intialization!
|> };

One helpful hint to avoid this problem is to initialize the variables the way
you would call a base class constructor, rather than in the body of the
constructor.

Thus
class Example {
	char * Point ;
public:
	Example(char * point) : Point(point) {}
};

With this syntax, interchanging the two will cause an error at compile time.
As a subtle point, this also *initializesa* Point, rather than *assigning* to
it.  This is irrelevant for a char*, but makes a difference for consts,
references, and user-defined classes where initialization and operator= are
different.

Anil A. Pal,	Silicon Graphics, Inc.
pal@sgi.com	(415)-335-7279