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Subject: Re: [boost] [TypeErasure] Forward constructors and binded types
From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2012-07-19 10:55:14


On 07/19/2012 07:36 AM, Larry Evans wrote:
> was most helpful to me. The attached shows
> that 2 different bindings can be used to create
> 2 arguments to a construction of the 3ird placeholder,
> and it still works. I would have thought that
> the same bindings would have been required for the
> placeholders.

They are. This happens to work because
I cheated a little in the assertions,
but it's really undefined behavior.

> The attached produces output of:
> St5dequeIdSaIdEE
> suggesting the type constructed comes from the 1st
> placeholder. When the code is changed to:
> any<construct, _b> size(10, bindings1);
> any<construct, _c> val(2.5, bindings2);
> the output is:
> St6vectorIdSaIdEE
> supporting the above conclusion.
> Do the docs say anywhere that this is what
> happens when 2 different bindings are used
> to construct something?

"The bindings of all the arguments that are any's, must be the same."

In Christ,
Steven Watanabe

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