Add support for cubic feet

src/conversions.rs

@@ -91,6 +91,11 @@ fn get_conversion(unit: NonMetric) -> Conversion {
 			from: inch_from * inch_from * inch_from,
 			to: MetricQuantity { amount: inch_to * inch_to * inch_to, unit: Metric::CubicMetre },
 		},
+		NonMetric::CubicFoot => Conversion {
+			offset: 0.0,
+			from: inch_from * inch_from * inch_from,
+			to: MetricQuantity { amount: 12.0 * inch_to * 12.0 * inch_to * 12.0 * inch_to, unit: Metric::CubicMetre },
+		},
 	}
 }
 
@@ -154,6 +159,7 @@ mod test {
 	fn volume() {
 		let tests = [
 			Test(NonMetric::CubicInch, 1.6387064e-5),
+			Test(NonMetric::CubicFoot, 0.028316846592),
 		];
 		run_tests(&tests, Metric::CubicMetre);
 	}

src/lib.rs

@@ -83,6 +83,7 @@ fn unit_to_name(unit: NonMetric) -> &'static str {
 		NonMetric::SquareMile => "square miles",
 		// Volume
 		NonMetric::CubicInch => "cubic inches",
+		NonMetric::CubicFoot => "cubic feet",
 	}
 }
 
@@ -123,5 +124,6 @@ mod test {
 		assert_eq!(run("1 mi²"), Ok("2.59 km²".to_string()));
 		// Volume
 		assert_eq!(run("1 in³"), Ok("16.39 cm³".to_string()));
+		assert_eq!(run("1 ft³"), Ok("28 317 cm³".to_string()));
 	}
 }

src/parse.rs

@@ -172,6 +172,19 @@ fn parse_unit(input: String) -> Result<NonMetric, ParseError> {
 		"inches^3" => Ok(NonMetric::CubicInch),
 		"in^3" => Ok(NonMetric::CubicInch),
 
+		"cubic foot" => Ok(NonMetric::CubicFoot),
+		"cubic feet" => Ok(NonMetric::CubicFoot),
+		"cubic ft" => Ok(NonMetric::CubicFoot),
+		"cu foot" => Ok(NonMetric::CubicFoot),
+		"cu feet" => Ok(NonMetric::CubicFoot),
+		"cu ft" => Ok(NonMetric::CubicFoot),
+		"foot³" => Ok(NonMetric::CubicFoot),
+		"feet³" => Ok(NonMetric::CubicFoot),
+		"ft³" => Ok(NonMetric::CubicFoot),
+		"foot^3" => Ok(NonMetric::CubicFoot),
+		"feet^3" => Ok(NonMetric::CubicFoot),
+		"ft^3" => Ok(NonMetric::CubicFoot),
+
 		_ => Err(ParseError::UnknownUnit(input)),
 	}
 }
@@ -393,6 +406,19 @@ mod test {
 		assert_eq!(parse_unit("inches^3".to_string()), Ok(NonMetric::CubicInch));
 		assert_eq!(parse_unit("in^3".to_string()), Ok(NonMetric::CubicInch));
 
+		assert_eq!(parse_unit("cubic foot".to_string()), Ok(NonMetric::CubicFoot));
+		assert_eq!(parse_unit("cubic feet".to_string()), Ok(NonMetric::CubicFoot));
+		assert_eq!(parse_unit("cubic ft".to_string()), Ok(NonMetric::CubicFoot));
+		assert_eq!(parse_unit("cu foot".to_string()), Ok(NonMetric::CubicFoot));
+		assert_eq!(parse_unit("cu feet".to_string()), Ok(NonMetric::CubicFoot));
+		assert_eq!(parse_unit("cu ft".to_string()), Ok(NonMetric::CubicFoot));
+		assert_eq!(parse_unit("foot³".to_string()), Ok(NonMetric::CubicFoot));
+		assert_eq!(parse_unit("feet³".to_string()), Ok(NonMetric::CubicFoot));
+		assert_eq!(parse_unit("ft³".to_string()), Ok(NonMetric::CubicFoot));
+		assert_eq!(parse_unit("foot^3".to_string()), Ok(NonMetric::CubicFoot));
+		assert_eq!(parse_unit("feet^3".to_string()), Ok(NonMetric::CubicFoot));
+		assert_eq!(parse_unit("ft^3".to_string()), Ok(NonMetric::CubicFoot));
+
 		// Unknown unit
 		assert_eq!(parse_unit("hutenosa".to_string()), Err(ParseError::UnknownUnit("hutenosa".to_string())));
 	}

src/units.rs

@@ -27,6 +27,7 @@ pub enum NonMetric {
 	SquareMile,
 	// Volume
 	CubicInch,
+	CubicFoot,
 }
 
 #[derive(Clone, Copy, Debug, PartialEq)]