Re: [Boost-users] [Range] invalid initialization of non-const type with adaptors

Subject: Re: [Boost-users] [Range] invalid initialization of non-const type with adaptors
From: Thorsten Ottosen (nesotto_at_[hidden])
Date: 2010-05-10 09:28:50

Neil Groves skrev:
> On Mon, May 10, 2010 at 2:35 AM, Denis Taniguchi <taniguchi_at_[hidden] 
> <mailto:taniguchi_at_[hidden]>> wrote:
> 
>     Hi,
> 
>     I was trying to compile the following simple piece of code:
> 
>     #include <boost/range/algorithm.hpp>
>     #include <boost/range/adaptors.hpp>
> 
>     #include <vector>
> 
>     int main(int argc, char *argv[])
>     {
>      std::vector<int> vec(10);
>      boost::fill(vec | boost::adaptors::reversed, 1);
> 
>      return 0;
>     }
> 
>     But I get the following erros with gcc (Ubuntu 4.3.3-5ubuntu4) 4.3.3:
>     Am I missing something here?

We shall ignore that there is no reason to use "reversed" here.

> 
> The reason this will not compile is that 'vec | 
> boost::adaptors::reversed' returns an unnamed temporary which is then 
> attempted to be passed to the fill function. On many versions of Visual 
> C++ this actually will compile and work as you intended due to a 
> language extension, but this is non-standard.

Does make_reverse_range(rng) not use iterator_range rather than sub_range?

Also, I don't see any reason why a const T& overload of boost::fill 
cannot exists as long as the const-iterator is actually a mutable 
iterator (like with iterator_range<MutableRange>).

-Thorsten