Re: [boost] [concept_check] addable

Subject: Re: [boost] [concept_check] addable
From: Dave Abrahams (dave_at_[hidden])
Date: 2012-04-20 03:07:37

on Fri Apr 20 2012, lcaminiti <lorcaminiti-AT-gmail.com> wrote:

> Dave Abrahams wrote
>> 
>> on Thu Apr 19 2012, lcaminiti <lorcaminiti-AT-gmail.com> wrote:
>> 
>>> Hello all,
>>>
>>> Does this Addable concept definition make sense to you? 
>> 
>> Well, it "makes sense," but...
>> 
>>> Is there any error?
>> 
>> That depends on what concept constraints you're trying to express.  This
>> definition tests that x + y is convertible to T.
>> 
>
> I wanted to check that there exist an operator+ from T x T to T "T
> operator+(T, T)" so I think that is what Addable<T> checks... 

Actually it checks that there exists an operator+ from T non-const
lvalue x T non-const lvalue to U, where U is convertible to T const&

> maybe the Sun's linker errors below are from something else (I've
> changed a regression test to get more info when it cycles tomorrow).

I don't know, but it seems unlikely.  Probably Sun's linker just needs a
body for return_type().

Cheers,

-- 
Dave Abrahams
BoostPro Computing
http://www.boostpro.com