Initial proof of concept

src/quantity/pressure.rs

@@ -0,0 +1,99 @@
+use crate::quantity::{KILO, Quantity, Value};
+use generate_quantity::quantity_type;
+
+const PASCALS_PER_TORR: f64 = 101325.0 / 760.0;
+const KILO_PASCALS_PER_PSI: f64 = 6.894757293168364;
+
+//----- Pascals ----------------------------------
+quantity_type! {Pascals, "Pa"}
+
+impl<V: Value> Pascals<V> {
+    #[inline]
+    pub fn to_kilo_pascals(self) -> KiloPascals<V> {
+        let divisor = V::from_u16(KILO).unwrap();
+        KiloPascals(self.0 / divisor)
+    }
+
+    // Should this be in separate imple with `V` bound to `num_traits::Float`?
+    #[inline]
+    pub fn to_torr(self) -> Torr<V> {
+        let divisor = V::from_f64(PASCALS_PER_TORR).unwrap();
+        Torr(self.0 / divisor)
+    }
+}
+
+//----- Kilopascals ----------------------------------
+quantity_type! {KiloPascals, "kPa"}
+
+impl<V: Value> KiloPascals<V> {
+    #[inline]
+    pub fn to_pascals(self) -> Pascals<V> {
+        let multiplier = V::from_u16(KILO).unwrap();
+        Pascals(self.0 * multiplier)
+    }
+
+    #[inline]
+    pub fn to_psi(self) -> Psi<V> {
+        let divisor = V::from_f64(KILO_PASCALS_PER_PSI).unwrap();
+        Psi(self.0 / divisor)
+    }
+}
+
+//----- Torr ----------------------------------
+quantity_type! {Torr, "Torr"}
+
+// Should this bound `V` to `num_traits::Float`?
+impl<V: Value> Torr<V> {
+    #[inline]
+    pub fn to_pascals(self) -> Pascals<V> {
+        let multiplier = V::from_f64(PASCALS_PER_TORR).unwrap();
+        Pascals(self.0 * multiplier)
+    }
+}
+
+//----- PSI ----------------------------------
+quantity_type! {Psi, "PSI"}
+
+impl<V: Value> Psi<V> {
+    #[inline]
+    pub fn to_kilo_pascals(self) -> KiloPascals<V> {
+        let multiplier = V::from_f64(KILO_PASCALS_PER_PSI).unwrap();
+        KiloPascals(self.0 * multiplier)
+    }
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+// ----- Tests ------------------------
+// ---------------------------------------------------------------------------------------------------------------------
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use float_cmp::assert_approx_eq;
+
+    #[test]
+    fn pascals_kilo_pascals() {
+        let pascals: Pascals<u32> = 1_000.pascals();
+        let kilo_pascals: KiloPascals<u32> = 1.kilo_pascals();
+
+        assert_eq!(pascals.0, kilo_pascals.to_pascals().0);
+        assert_eq!(kilo_pascals.0, pascals.to_kilo_pascals().0);
+    }
+
+    #[test]
+    fn torr_pascals() {
+        let torr: Torr<f32> = 7.5.torr();
+        let pascals: Pascals<f32> = 999.9177631578947.pascals();
+
+        assert_approx_eq!(f32, pascals.to_torr().0, torr.0);
+        assert_approx_eq!(f32, torr.to_pascals().0, pascals.0);
+    }
+
+    #[test]
+    fn psi_kilo_pascals() {
+        let psi: Psi<f32> = 2.5.psi();
+        let kilo_pascals: KiloPascals<f32> = 17.23689323292091.kilo_pascals();
+
+        assert_approx_eq!(f32, psi.to_kilo_pascals().0, kilo_pascals.0);
+        assert_approx_eq!(f32, kilo_pascals.to_psi().0, psi.0);
+    }
+}