Re: [boost] [contract] concepts: pseudo-signatures vs. usage patterns

Subject: Re: [boost] [contract] concepts: pseudo-signatures vs. usage patterns
From: Dave Abrahams (dave_at_[hidden])
Date: 2012-10-11 20:27:31

on Thu Oct 11 2012, Andrew Sutton <asutton.list-AT-gmail.com> wrote:

>> You're missing the point.  I claim the associated "argument type" of
>> Predicate is char.  The value type of the sequence (int) is convertible
>> to the associated argument type.  That's all that's required according
>> to the text.
>
> Sorry... you're right. If the requirement is that the value type is
> convertible to the argument type, then yes.  Fortunately that's not
> what we required in n3351.

OK.

For examples of forced conversions inserted to deal with this issue,
search for "pred" in
http://gcc.gnu.org/viewcvs/trunk/libstdc%2B%2B-v3/include/bits/stl_algo.h?view=markup

Looking at N3351, I wonder if you implemented these algorithms and threw
strict archetypes at the implementations.  It looks very much like you
would need similar contortions.

-- 
Dave Abrahams
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