void foo() { using boost::units::quantity; using namespace boost::units::data_capacity;
//Both of these fail with the message that there is no conversion to the destination //type because the construcor is explicit quantity<data_capacity> compressed_size = 1000 * bytes; quantity<data_capacity, int> compressed_size2 = 1000 * bytes;
Implicit conversion is not allowed, and default value type is double - try : quantity<data_capacity> compressed_size(1000.0*bytes); quantity<data_capacity,int> compressed_size2(1000*bytes);
//Succeeds but gives a horribly long warning about conversion from 'double' to 'const int' //at file 'boost/units/detail/conversion_impl.hpp(342)', reference to class template instantiation at //boost/units/quantity.hpp(182) quantity<data_capacity, int> compressed_size3(1000 * bytes); }
If I remember correctly, this stems from the use of double precision in the conversion code. I think it would be difficult to get rid of this - most computations involving unit conversions do not involve exact integer arithmetic... Matthias