Re: [boost] [Conversion] Review

Subject: Re: [boost] [Conversion] Review
From: Vicente J. Botet Escriba (vicente.botet_at_[hidden])
Date: 2011-08-28 06:07:05

Le 28/08/11 09:43, Antony Polukhin a écrit :
> First of all, there is already a Boost.Conversion library (released in
> 1.20.0). Users will be confused, because two libraries have same
> names.
I pretended to include the 'generic' conversions into the conversion 
library.
> * What is your evaluation of the design?
>
> It is simple and looks good. But consider the following situation:
> lexical_cast<char>(1) and numeric_cast<char>(1) will produce output.
> It must be documented, which cast will your library use in which
> cases.
The documentation of header <boost/conversion/std/string.hpp> includes
"Include this file when using conversions from/to |std::string| via 
|lexical_cast|. "

> There must be some tags, to allow user to choose, which conversion is
> required. There are some dummy::type_tag tags in source code, but
> looks like they are not used, and not documented!
They are used to overload the conversion functions. The class is 
documented here 
https://svn.boost.org/svn/boost/sandbox/conversion/libs/conversion_ext/doc/html/boost/conversion/dummy/type_tag.html. 
This 
https://svn.boost.org/svn/boost/sandbox/conversion/libs/conversion_ext/doc/html/boost/conversion/users_guide.html#boost.conversion.users_guide.tutorial.how_to_specialize_extrinsic_conversions_ 
tutorial section explains how to use it.
>
> * What is your evaluation of the documentation?
>
> There is no documentation about which conversion when used.
> convert_to<char>(1) will call numeric_cast or lexical_cast?
The library doesn't provide a conversion from int to string if you don't 
include the specific file mentioned above.
>
> * Do you think the library should be accepted as a Boost library?
>
> Yes, it should. But only after the documentation will be updated and
> tags added. Until then, it is not clear which cast is when used and
> library is not as generic as possible. But such big changes to library
> design will require some new short review.

Could you elaborate on how you see the library can use these tags?

Thanks for your review,
Vicente