Type-safe calculations using different units of measurement

calculations.ts

import {Feet, Meters, Measurement, toMeasurement} from './units-of-measurement';

function area<T extends Measurement>(width: T, height: T): T {
    return toMeasurement<T>(width * height);
}

const widthFeet = toMeasurement<Feet>(4);
const heightFeet = toMeasurement<Feet>(5);
const areaFeet = area<Feet>(widthFeet, heightFeet);

const widthMeters = toMeasurement<Meters>(4);
const heightMeters = toMeasurement<Meters>(5);
const areaMeters = area<Meters>(widthMeters, heightMeters);

const areaFailure1 = area<Feet>(widthFeet, heightMeters); // Error: Argument of type 'Meters' is not assignable to parameter of type 'Feet'.
const areaFailure2 = area<Meters>(widthFeet, heightMeters); // Error: Argument of type 'Feet' is not assignable to parameter of type 'Meters'.
const areaFailure3 = area<Feet>(4, 5); // Error: Argument of type 'number' is not assignable to parameter of type 'Feet'.