[boost] Re: Math constants - updated.

From: Tobias Schwinger (tschwinger_at_[hidden])
Date: 2005-05-08 06:06:22

Andy Little wrote:
> 
> "Tobias Schwinger" <tschwinger_at_[hidden]> wrote
> 
>> Static constants in "<type>_constants"-namespaces are also 
>> undesirable, because there is no way to select a namespace named 
>> "<T>_constants" from within a template.
> 
> 
> FWIW thi would work fine for me:
> 
>    typedef  std::math::constants<T> math;
>     2 * math::pi * r ;

This looks nice at first glance.

Besides getting rid of the empty parentheses, there are the following disadvantages:

- modularity/extensibility (once constants<T> is defined you can't add constants 
to it)
- portability (the code above won't compile with BCC)
- there is no way to pass constants as a type template argument

Regards,

Tobias