How to handle units in c++ interface

Question

I am currently designing an API where I want that the user to be able to write code like this:

PowerMeter.forceVoltage(1 mV);
PowerMeter.settlingTime(1 ms);
         


        

Answer 1

Take a look at Boost.Units. Here's some example code:

quantity
work(const quantity& F, const quantity& dx)
{
    return F * dx; // Defines the relation: work = force * distance.
}

...

/// Test calculation of work.
quantity     F(2.0 * newton); // Define a quantity of force.
quantity    dx(2.0 * meter); // and a distance,
quantity    E(work(F,dx));  // and calculate the work done.