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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: How do I write directly to a memory address?
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Date: Mon, 7 Feb 2011 10:24:49 +0100
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Date: 2011-02-07T10:24:50+01:00
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On Mon, 7 Feb 2011 01:05:20 -0800 (PST), Maciej Sobczak wrote:

> On Feb 7, 9:38�am, "Dmitry A. Kazakov" <mail...@dmitry-kazakov.de>
> wrote:
> 
>>> Scalar arguments are passed by copy, so whether they are immutable or
>>> mutable within the function is independent on their origin (and the
>>> original is not affected by this in any way).
>>> Unless, of course, you have meant something else.
>>
>> Exactly this. Passing mode (by copy vs. by reference) has nothing to do
>> with the mutability contract. Unchanged origin is no argument, because the
>> contract is broken [*].
> 
> The contract is not broken. The function cannot modify the original
> value that is passed by copy (this being the very nature of "copy")
> and the caller cannot even reason about what happens behind the
> signature.

It is broken because const T is not substitutable for T. Mutators of the
type T are not operations of const T. q.e.d.

P.S. Contract is between two parties.

P.P.S. You may have a working program full of unstated, idiotic,
meaningless, broken contracts. This is how modern S/W industry works.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de