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Subject: Re: [boost] [conversion] How to repere assignement to a variable? (was [property] interest in C# like properties for C++?)
From: Stewart, Robert (Robert.Stewart_at_[hidden])
Date: 2009-10-22 10:58:31

vicente.botet wrote:
> in the thread about C# like properties we were talking about
> the advantage to be able to repere assignation to properties.

I assume by "repere assignation" you mean, in English, "represent assignment." ("Assignation" is not used, normally, as a synonym for "assignment.")

> I said that, another way to repare the assignments is to use
> a free function assign_to, like we use the free function
> swap, or the cast family functions.
> assign_to(a.p_X, 1);
> assign_to call by default the assignment operator.

That's a reasonable default while permitting customization. The idea is reasonable, because it can be customized to recognize properties, however implemented, as well as normal data types, to provide a common "assignment syntax" that adapts to the types used.

However, operator = can be likewise customized and is idiomatic for assignment. Why create a new name?

> If we want transitive assignation
> a = b = c;
> we could do
> assign_to(a, assign_to(b, c));
> and if we find this not really readable we can try with
> tie(a) = tie(b) = c;

Neither is good, but transitive assignment can be ignored; it is hardly a critical feature. (I rarely use it.)

Rob Stewart robert.stewart_at_[hidden]
Software Engineer, Core Software using std::disclaimer;
Susquehanna International Group, LLP

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