On 03/10/2014 01:37 PM, Steven Watanabe wrote:

AMDG

On 03/10/2014 10:12 AM, Roger Martin wrote:

...

I've tried and tried and just not understanding or can't muddle my way through the boost units(looks powerful though). For a start, just trying to get at the speed of light in boost/units/systems/si/codata/universal_constants.hpp

boost::units::si::constants::codata::c boost::units<boost::units::si>::constants::codata::c.value() and massive errors; especially if I try to multiplying with something.

I use boost::math::constants::pi<double>() from #include "boost/math/constants/constants.hpp"

But the universals allude me; and example? where is my brain stuck?

I'm not sure. You'll need to give more details. (preferable a small /complete/ program that doesn't compile)

The following seems to work for me. (I did run into the fact that there's a missing #include<boost/units/quantity.hpp> in the constants.) Ah thank you! I was only using the single header #include <boost/units/systems/si/codata_constants.hpp> or with the #include <boost/units/systems/si.hpp> before it. And I didn't know about the boost/units/io.hpp when cout'ing either. Working in a cunit; I'll make a more complete code example with tests for it and reply again.

I got going with what you showed me but learned the multiplication needs casting to long double before the math would work/compile. And division(I'll try more operations). std::cout<< boost::units::si::constants::codata::c * 2.5l<< std::endl; failed for me while std::cout<< boost::units::si::constants::codata::c * 2.5<< std::endl; works.

#include<boost/units/quantity.hpp> #include<boost/units/systems/si/codata_constants.hpp> #include<boost/units/io.hpp> #include<iostream>

int main() { std::cout<< boost::units::si::constants::codata::c * 2.5<< std::endl; }

In Christ, Steven Watanabe

_______________________________________________ Unsubscribe& other changes: http://lists.boost.org/mailman/listinfo.cgi/boost