Hello, I am working on some trajectory calculations, and having a strange compiler error. First, great that I should get a compiler error at all! Second, what am I missing? quantity<acceleration> g() { static const auto gValue = static_cast<double>(9.812); static const auto metersPerSecondPerSecond = meters / second / second; static const quantity<acceleration> g = gValue*metersPerSecondPerSecond; return g; } double Class1::CalculateZeta(double timeMilliseconds, double heightMeters) { static const auto two = static_cast<double>(2); static const auto milliseconds = milli*seconds; const auto t = timeMilliseconds*milliseconds; const auto h = heightMeters*meters; const auto g_ = g(); auto result = -(g_ / two)*(t*t) + h; return result.value(); } Just if I did the dimensional analysis, I might expect the time components (i.e. T^2) to cancel themselves out, which should leave me with length+length, no? This is exposed via a C++ CLR (VS2013), but the Boost.Units are done internally. What am I missing here? I need to normalize the units, say to meters, etc? Best regards, Michael Powell Errors: Error 4 error C2676: binary '+' : 'boost::units::quantity<boost::units::unit<boost::units::list<boost::units::dim<Derived,boost::units::static_rational<1,1>>,boost::units::dimensionless_type>,boost::units::heterogeneous_system<boost::units::heterogeneous_system_impl<boost::units::list<boost::units::heterogeneous_system_dim<boost::units::si::meter_base_unit,boost::units::static_rational<1,1>>,boost::units::dimensionless_type>,boost::units::list<boost::units::dim<Derived,boost::units::static_rational<1,1>>,boost::units::dimensionless_type>,boost::units::list<boost::units::scale_list_dim<Scale>,boost::units::dimensionless_type>>>,void>,double>' does not define this operator or a conversion to a type acceptable to the predefined operator I:\Source\Spikes\Kingdom.Physics\src\Kingdom.Physics.Calculators\Class1.cpp 43 1 Kingdom.Physics.Calculators Error 2 error C2784: 'add_typeof_helper<boost::units::unit<Dim1,System1,void>,boost::units::unit<Dim2,System2,void>>::type boost::units::operator +(const boost::units::unit<Dim1,System1,void> &,const boost::units::unit<Dim2,System2,void> &)' : could not deduce template argument for 'const boost::units::unit<Dim1,System1,void> &' from 'boost::units::quantity<boost::units::unit<boost::units::list<boost::units::dim<Derived,boost::units::static_rational<1,1>>,boost::units::dimensionless_type>,boost::units::heterogeneous_system<boost::units::heterogeneous_system_impl<boost::units::list<boost::units::heterogeneous_system_dim<boost::units::si::meter_base_unit,boost::units::static_rational<1,1>>,boost::units::dimensionless_type>,boost::units::list<boost::units::dim<Derived,boost::units::static_rational<1,1>>,boost::units::dimensionless_type>,boost::units::list<boost::units::scale_list_dim<Scale>,boost::units::dimensionless_type>>>,void>,double>' I:\Source\Spikes\Kingdom.Physics\src\Kingdom.Physics.Calculators\Class1.cpp 43 1 Kingdom.Physics.Calculators Error 3 error C2893: Failed to specialize function template 'add_typeof_helper<boost::units::quantity<Unit1,X>,boost::units::quantity<Unit2,Y>>::type boost::units::operator +(const boost::units::quantity<Unit1,X> &,const boost::units::quantity<Unit2,Y> &)' I:\Source\Spikes\Kingdom.Physics\src\Kingdom.Physics.Calculators\Class1.cpp 43 1 Kingdom.Physics.Calculators 5 IntelliSense: no operator "+" matches these operands operand types are: boost::units::quantity<boost::units::unit<boost::units::list<boost::units::dim<boost::units::length_base_dimension, boost::units::static_rational<1L, 1L>>, boost::units::dimensionless_type>, boost::units::heterogeneous_system<boost::units::heterogeneous_system_impl<boost::units::list<boost::units::heterogeneous_system_dim<boost::units::si::meter_base_unit, boost::units::static_rational<1L, 1L>>, boost::units::dimensionless_type>, boost::units::list<boost::units::dim<boost::units::length_base_dimension, boost::units::static_rational<1L, 1L>>, boost::units::dimensionless_type>, boost::units::list<boost::units::scale_list_dim<boost::units::scale<10L, boost::units::static_rational<-6L, 1L>>>, boost::units::dimensionless_type>>>, void>, double> + const boost::units::quantity<boost::units::unit<boost::units::length_dimension, boost::units::si::system, void>, double> i:\Source\Spikes\Kingdom.Physics\src\Kingdom.Physics.Calculators\Class1.cpp 43 49 Kingdom.Physics.Calculators