[prev in list] [next in list] [prev in thread] [next in thread] 

List:       boost-users
Subject:    Re: [Boost-users] [EXTERNAL] [ Boost.Units ] Invert a quantity_type
From:       "Belcourt, Kenneth via Boost-users" <boost-users () lists ! boost ! org>
Date:       2017-06-09 15:41:36
Message-ID: 5952CFC6-4751-49DF-A336-E3F03805241F () sandia ! gov
[Download RAW message or body]


> On Jun 8, 2017, at 1:51 PM, Steven Watanabe via Boost-users \
> <boost-users@lists.boost.org> wrote: 
> AMDG
> 
> On 06/06/2017 05:12 PM, Belcourt, Kenneth via Boost-users wrote:
> > 
> > I have a structure that is passed some type from which I can extract a units \
> > quantity type: 
> > <snip>
> > 
> > Is there a way to invert a quantity type so I can compute and return, say, the \
> > inverse of the passed quantity_type?  So, for example, is there any Boost.Units \
> > inverse meta like function that might let me say something like this: 
> > <snip>
> > I'm hoping for something more general than partially specializing the bu::inverse \
> > method for each quantity I may want to invert.  Any ideas? 
> 
> There isn't a specific inverse function, but,
> shouldn't divide_typeof_helper work or
> power_typeof_helper<T, -1> work?  (or better
> just use decltype)

Sure, thought about using the helper functions, but they're all marked as non-public \
APIs.

/// INTERNAL ONLY
template<class System,
         class Dim,
         class X>
struct divide_typeof_helper< X,unit<Dim,System> >

So don't want to depend on bu implementation details.

As for decltype, that's possibly a bridge too far for less experienced developers so, \
for now, I still prefer explicit typing where I can.

I appreciate the help Steven, thanks for suggestions!

_______________________________________________
Boost-users mailing list
Boost-users@lists.boost.org
https://lists.boost.org/mailman/listinfo.cgi/boost-users


[prev in list] [next in list] [prev in thread] [next in thread]