"Deane Yang" wrote
It could be just me, but I'd like to be at least warned if I manage to write code that contained
quantity_in_inches + quantity_in_meters
or even
quantity_in_millimeters - quantity_in_kilometers
Both to me are signs that something went wrong.
Actually I had just a problem the other day where the conversion came in handy. i wanted to find postage for an item to go on ebay. I had a kitchen scales that works in lb and oz, and which was also not adequte to weigh the item which was around 15 kg. in weight. So I got a plank of wood and put one end to the floor and the other to the scales. Then I put the ebay-item on some way down the wood so I didnt max out the scales. Then I did a quick C++ program with pqs library to get the result. It sure was easy not having to do all the conversions by hand. Heres the program: #include <pqs/pqs.hpp> int main() { pqs::length::m L1(1.57); // ebay_item disance along beam to scale pqs::length::m L2(.47); // ebay-item distance to beeam end on floor pqs::length::m L = L1 + L2; // total beam length pqs::mass::kg m1 = pqs::mass::lb(9) + pqs::mass::oz(6); // mass read by scales with item pqs::mass::kg m2 = pqs::mass::lb(2) + pqs::mass::oz(10); // mass of beam only pqs::mass::kg m = m1 - m2; // mass on scales to due ebay-item pqs::mass::kg result = m * L / L2; // scale by moment std::cout << result <<'\n'; } This also occurs with user input which often requires a conversion from e.g imperial units to S.I. units. cheers Andy Little