Re: Why properties cannot be used as ref or out arguments

Yeah - getting my head around it now. Sadly, it's not VB I wanted it
for.

Is a shame- looks like I will have to declare 2 variables, pass them in,
and then analyse the returned responses to achieve what I want - takes
the "ideal" 1 line call to about 7 or 8 at least - was trying to
encapsulate a call, but it might not be feasible.

Dino

-----Original Message-----
From: Discussion of development on the .NET platform using any managed
language [mailto:[email protected]] On Behalf Of Jon Skeet
Sent: Monday, 10 March 2008 22:32
To: [email protected]
Subject: Re: [DOTNET-CLR] Why properties cannot be used as ref or out
arguments

Dean Cleaver wrote:
> I can understand ref arguments, because they might not be set on
> passing, but I can't figure out why they can't be used as out
arguments?
>
> Any thoughts?

That's not the reason for not being able to use them as ref.

When you pass a parameter by out/ref, you're effectively passing an
address that the called method can use as the variable address. It can
treat it like any other variable in terms of storing and fetching values
directly (subject to definite assignment rules for out, of course).

Properties don't work like this - they're not slots in memory, to be
arbitrarily accessed.


Note that if you use properties for out/ref parameters in VB, basically
a temporary variable is created, *that* is passed by out/ref, and the
property is set appropriately after method has completed.

Jon

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