AMDG
detail/conversion_impl.hpp:345
On 02/17/2014 07:40 AM, Lindley French wrote:
> For the life of me I can't figure out where the actual multiplication of
> the value occurs. Boost Units is very clever template magic, but I doubt
> anyone could maintain the thing without weeks of studying the design....
>
return(destination_type::from_value(static_cast<T2>(source.value() *
conversion_factor(u1, u2))));
This won't really help you because
the result of conversion_factor
returns a double.
The scale is evaluated at detail/conversion_impl.hpp:448
return(conversion1::value() * (scale::value() /
conversion2::value()));
"scale" here is the result of get_scale_list/eval_scale_list.
get_scale_list collects the scaling factors, eval_scale_list
multiplies their ::value() together.
Again, scale::value() returns a double, because the
individual scale factors use double. (See scale.hpp)
There's a metafunction called get_scale_list,
>
> On Mon, Feb 17, 2014 at 9:48 AM, Lindley French <lindleyf@gmail.com> wrote:
>
>> What's the best way to access the current scaling of a dimensionless
>> value? Maybe I can back it out myself rather than relying on type
>> conversion to do it.
>>
which returns an MPL sequence whose members
contain
static const long base = ...;
typedef static_rational<...> exponent;
It's not documented, so use it at your own risk.
It's unlikely to change, but I make no guarantees.
In Christ,
Steven Watanabe
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