Protected parameters, 2nd try_(re)

08 Mar 97 10:57:49 EST

Oops, sended the msg already. Here again:


>> Does that mean that protected (not protected var) parameters
>> are passed by value?  Especially in the case of large 
>> structures, can this be inefficient, taking up stack space
>> and consuming time to copy the arguments?

> Yes.  :-(

>> Or does the standard prescribe something different?

> Yes.  It requires that the value of the protected formal 
> parameter cannot change during the execution of the function,

The standard doesn't define it this way. I too think that protected should be
treated exactly like var parameters, or whatever is as efficient or more
efficient (that's why I use const parameters for in Borland Delphi).

The standard says this about protected parameters:

	peter is essentially correct.
	(and my initial sentence was incorrect)


After a 2nd reading and some trying I don't see a better way to implement it.
The compiler would have a really hard job to change protected to protected var
when that is allowed.

There is a few cases where it might be a little bit less hard. I think the case
when there are no var parameters (so there is no aliasing) protected should be
protected var.

Groetjes,

Berend.

Berend de Boer (100120.3121@CompuServe.COM)