Re: [Boost-users] [Units]

Subject: Re: [Boost-users] [Units]
From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2017-10-05 04:29:22

AMDG

On 10/04/2017 07:58 PM, CD Clark via Boost-users wrote:
> <snip>
> // centimeter
> namespace t { typedef make_scaled_unit< si::length, scale< 10,
> static_rational<-2> > >::type cm; }
> namespace i { BOOST_UNITS_STATIC_CONSTANT( cm, t::cm ); }
> 
> <snip>
> 
> // centimeter squared
> namespace t { typedef multiply_typeof_helper< cm, cm>::type cm_cm; }
> namespace i { BOOST_UNITS_STATIC_CONSTANT( cm_cm, t::cm_cm ); }
> 
> <snip>
>   //std::cout << i::cm_cm << std::endl; // this won't compile
> 
> <snip>
> If I uncomment the line that tries to print i::cm_cm it won't compile. I
> get an error that says
> 
> 'symbol' is not a member of ...
> 
> and points at a line that says
> 
> str += Begin::item::symbol()
> 
> I can't understand why it doesn't work for a product of two scaled units.
> 

  The reason that it fails is that the output code
instantiates the default implementation even if
you override it.  The problem is that there is
no symbol defined for 10^-4.

In Christ,
Steven Watanabe