Re: [boost] Guid library

From: Andy (atompkins_at_[hidden])
Date: 2007-03-20 16:22:51

me22 <me22.ca_at_[hidden]> wrote in
news:fa28b9250703201126y574108d7r1c6f5f9d4584745a_at_[hidden]: 

> Small thing I noticed in the implementation of
>     template <typename ByteInputIterator>
>     guid(ByteInputIterator first, ByteInputIterator last)
>     {
>         if (std::distance(first, last) != 16) {
>             boost::throw_exception(std::invalid_argument("invalid
> input iterator pair, must span 16 bytes"));
>         }
>         data_type::iterator i_data = data_.begin();
>         while (first != last) {
>             *i_data++ = numeric_cast<uint8_t>(*first++);
>         }
>     }
> You suggest that you want input iterators, and the invalid_argument
> message mentions input iterators, but your code doesn't work with
> input iterators as it traverses the range twice.

Good point!  Thanks.

> 
> It should probably ask for forward iterators or use something like
> 
>     template <typename ByteInputIterator>
>     guid(ByteInputIterator first, ByteInputIterator last)
>     {
>         data_type::iterator i_data = data_.begin();
>         int i = 0;
>         for (; i < 16 && first != last; ++i) {
>             *i_data++ = numeric_cast<uint8_t>(*first++);
>         }
>         if ( i != 16 ) {
>             boost::throw_exception(std::invalid_argument("invalid
> input iterator pair, must span at least 16 bytes"));
>         }
>     }
> 
> ~ Scott McMurray
> 

I will add this to my to do list.

Andy.

< snip >