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List:       kde-devel
Subject:    Re: strings and QStrings
From:       David van Hoose <david-vh () home ! com>
Date:       2000-12-10 20:07:16
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Patrick Julien wrote:
> 
> On December 10, 2000 02:07 pm, David van Hoose wrote:
> > Patrick Julien wrote:
> > > Actually, the object is not being returned by operator=, a reference to
> > > that object is returned, so no constructor
> >
> > Yeah.. That is what it is supposed to do. GCC has some bugs.
> > One of the bugs is the overruling of the = operator as
> > an implicit constuctor alias even if the = operator is different.
> 
> since when?!?  If you use the exemple, you can determine that it is in fact,
> doing The Right Thing.  Just add a print in B constructor and change the copy
> constructor B(const A&a) to say constructing a copy of b from a.
> 
> > This violates the ISO draft. In reality, the GCC compiler does
> > not follow the ISO draft at all. It is worse than the Borland
> > compiler at skrewing things up.
> 
> Look, the operator= method is not even being called cuz that's not what's
> going on here.  In the example,
> 
>         B b1 = a;
> 
> this is not operator=, this is the copy constructor.  It doesn't have
> anything to do with overruling.  This is exactly the same has
> 
>         B b1 ( a );

Not in ALL cases. This is an example of gross neglect of the human mind.
In cases in which the code for the = operator and the constructor are
different, the logic flow can be damaged by this alias. Any standard
dealing with this should read:

"If an assignment operator is used during the declaration process,
a typecast constructor shall be used except in cases in which the
assignment operator has been explicitly defined."

This would prevent damage to the flow of logic.
Do you understand what I saying?

> In fact, this is old C, the following will generate the same code.
>         int i = 0; <==> int i ( 0 );
> 
> But this won't,
> 
>         int i = 0;
>         and
>         i = 3;

No.. Since 'int' is a processor type, it doesn't activate a function at
all.

-- 
-Dave
 
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