Re: [boost] Boost.Algorithm design question

Subject: Re: [boost] Boost.Algorithm design question
From: Dave Abrahams (dave_at_[hidden])
Date: 2011-10-06 15:54:57

on Thu Oct 06 2011, Marshall Clow <mclow.lists-AT-gmail.com> wrote:

>> template< typename Iter >
>>    requires
>>        InputIterator<Iter>, 
>>        EqualityComparable<iterator_traits<Iter>::value_type>
>> bool none_of_equal ( Iter first, Iter last,
>> iterator_traits<Iter>::value_type const& value ) ; // option 2
>
> I think you're missing the requirement is that the value passed in be
> convertible to "iterator_traits<Iter>::value_type", since that is what
> will happen at the call site.

No! <sorry, I'm getting excited>

If I write a function that takes an int, do I have to specify that you
can pass "anything convertible to an int?"  No!  The same applies f when
you write a function that takes a reference to the iterator's
value_type.  The function signature clearly says what is happening.

The fact that a conversion can happen is not the algorithm author's
problem when written this way.

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