Re: [Boost-users] [units] unit conversion on construction in relation to argument passing

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nice! But for some reason I believe this would work for argument functions

double f(quantitysi::length v){ return 1.;} ... quantitycgs::lengh A = 4.*cgs::centimeter f(A); // doesn't work! not matching function

why is this? isn't the argument of the call a sort of construction argument for the function argument, or is more like a plain assignment. Is there a way to force the automatic conversion of the function call.

Or I am forced to use this other long call?

f(quantitysi::length(A));

Yes. The constructor is explicit.

Or you can write it as a template function that takes any argument that is a quantity of length : #include <iostream> #include #include #include using namespace boost::units; template Y f(quantity,Y> v) { const Y w = quantitysi::length,Y(v).value(); std::cout << v << "\t" << w << std::endl; return w; } int main(void) { f(quantitycgs::length,double(17.0*cgs::centimeters)); return 0; } Matthias