Merge pull request #136 from dunmatt/aa

Add `AngularAcceleration`.

src/si/angular_acceleration.rs

@@ -0,0 +1,48 @@
+//! Angular acceleration (base unit radian per second squared, s⁻²).
+
+quantity! {
+    /// Angular acceleration (base unit radian per second squared, s⁻²).
+    quantity: AngularAcceleration; "angular acceleration";
+    /// Dimension of angular acceleration, T⁻² (base unit radian per second squared, s⁻²).
+    dimension: ISQ<
+        Z0,     // length
+        Z0,     // mass
+        N2,     // time
+        Z0,     // electric current
+        Z0,     // thermodynamic temperature
+        Z0,     // amount of substance
+        Z0>;    // luminous intensity
+    kind: ::si::marker::AngleKind;
+    units {
+        /// Derived unit of angular acceleration.
+        @radian_per_second_squared: 1.0; "rad/s²", "radian per second squared",
+            "radians per second squared";
+        @degree_per_second_squared: 1.745_329_251_994_329_5_E-2; "°/s²",
+            "degree per second squared", "degrees per second squared";
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    storage_types! {
+        use num::One;
+        use si::angle as a;
+        use si::angular_acceleration as aa;
+        use si::quantities::*;
+        use si::time as t;
+        use tests::Test;
+
+        #[test]
+        fn check_units() {
+            test::<a::radian, t::second, aa::radian_per_second_squared>();
+            test::<a::degree, t::second, aa::degree_per_second_squared>();
+
+            fn test<A: a::Conversion<V>, T: t::Conversion<V>, R: aa::Conversion<V>>() {
+                let square_second = Time::new::<T>(V::one()) * Time::new::<T>(V::one());
+
+                Test::assert_approx_eq(&AngularAcceleration::new::<R>(V::one()),
+                    &(Angle::new::<A>(V::one()) / square_second).into());
+            }
+        }
+    }
+}

src/si/mod.rs

@@ -38,6 +38,7 @@ system! {
         acceleration::Acceleration,
         amount_of_substance::AmountOfSubstance,
         angle::Angle,
+        angular_acceleration::AngularAcceleration,
         area::Area,
         available_energy::AvailableEnergy,
         capacitance::Capacitance,