Re: [boost] Re: Re: Re: Re: Numeric conversions lib comments

From: Peter Dimov (pdimov_at_[hidden])
Date: 2004-03-28 08:26:38

Jonathan Turkanis wrote:
> "Peter Dimov" <pdimov_at_[hidden]> wrote in message
> news:004101c41369$2ca8cb90$1d00a8c0_at_pdimov2...
>
>> And for the string case, the downside to encoding a comparison in
> the type
>> is that you'll now spend a lot of time converting strings (because
> most
>> libraries - correctly - accept an ordinary std::string, regardless
> of what
>> comparisons they might make underneath, or they'd expose
> implementation
>> details in the interface.)
>
> You can expose the string as a typedef, to avoid bothering library
> users with custom comparison policies. Most of the interoperability
> concerns could be addressed by relaxing the requirement that
> traits_type match extacly in basic_string member functions which take
> basic_strings as arguments -- at least for those which don't involve
> comparison.

Nice theory, but nobody has ever tried it in practice. Not that there's any
need to. std::string works, and nobody uses the 'Traits'. Besides, you'll
still introduce unneeded string copies.