Added SpecificWeight = Pressure / Length

Author: gojanpaolo

UnitsNet.Tests/CustomCode/PressureTests.cs

@@ -121,5 +121,12 @@ public void PressureDividedBySpecificWeightEqualsLength()
             Length length = Pressure.FromPascals(20) / SpecificWeight.FromNewtonsPerCubicMeter(2);
             Assert.Equal(Length.FromMeters(10), length);
         }
+
+        [Fact]
+        public void PressureDividedByLengthEqualsSpecificWeight()
+        {
+            SpecificWeight specificWeight = Pressure.FromPascals(20) / Length.FromMeters(2);
+            Assert.Equal(SpecificWeight.FromNewtonsPerCubicMeter(10), specificWeight);
+        }
     }
 }

UnitsNet/CustomCode/Quantities/Pressure.extra.cs

@@ -47,6 +47,11 @@ public partial struct Pressure
         {
             return new Length(pressure.Pascals / specificWeight.NewtonsPerCubicMeter, UnitsNet.Units.LengthUnit.Meter);
         }
+
+        public static SpecificWeight operator /(Pressure pressure, Length length)
+        {
+            return new SpecificWeight(pressure.Pascals / length.Meters, UnitsNet.Units.SpecificWeightUnit.NewtonPerCubicMeter);
+        }
 #endif
     }
 }