AMDG Damien R wrote:

I just discover boost::units and I want to know how it works in this case : quantitysi::plane_angle angle(45 * degree);

When the constructor is called, is the argument converted in radian or not ?

The value is converted into radians.

Moreover, it is possible to have : quantity angle(45 * degree); angle += pi / 4 * radian; cout << angle << endl; cout << quantitydegree::plane_angle(angle) << endl; cout << quantityradian::plane_angle(angle) << endl; cout << angle.value<degree>() << endl; cout << angle.value<radian>() << endl;

output : 45 deg + pi / 4 rad

This is not possible.

90 deg pi / 2 rad

You would get 1.57..., not pi/2

90 1.57079632679

This can be done with quantitydegree::plane_angle(angle).value() e.g.. In Christ, Steven Watanabe