Implement TryFrom for enumerations

Author: twistedfall

CHANGES.md

@@ -1,3 +1,6 @@
+* 0.91.1
+  * Add `TryFrom<i32>` impls for enums to allow easy fallible conversions from `i32`.
+
 * 0.91.0
   * Multiple improvements for `InputArray`/`OutputArray`/`InputOutputArray` handling:
     * It's now possible to use the following types as `InputArray`: `&[u8]`/`[u8; N]`, `Vector<bool>` `Vector<GpuMat>` and the

binding-generator/src/writer/rust_native/enumeration.rs

@@ -41,40 +41,53 @@ impl RustNativeGeneratedElement for Enum<'_> {
 		static CONST_IGNORED_TPL: Lazy<CompiledInterpolation> =
 			Lazy::new(|| include_str!("tpl/enum/const_ignored.tpl.rs").compile_interpolation());
 
+		static FROM_CONST_TPL: Lazy<CompiledInterpolation> =
+			Lazy::new(|| include_str!("tpl/enum/from_const.tpl.rs").compile_interpolation());
+
+		static FROM_CONST_IGNORED_TPL: Lazy<CompiledInterpolation> =
+			Lazy::new(|| include_str!("tpl/enum/from_const_ignored.tpl.rs").compile_interpolation());
+
 		let consts = self.consts();
-		let mut generated_values = HashMap::with_capacity(consts.len());
-		let consts = consts
-			.into_iter()
-			.map(|c| {
-				let name = c.rust_leafname(FishStyle::No).into_owned();
-				let value = c.value().expect("Can't get value of enum variant").to_string();
-				let duplicate_name = generated_values.get(&value).cloned();
-				let tpl = if duplicate_name.is_some() {
-					&CONST_IGNORED_TPL
-				} else {
-					&CONST_TPL
-				};
-				let comment_marker = if duplicate_name.is_some() {
-					"//"
-				} else {
-					"///"
-				};
-				let doc_comment = c.rendered_doc_comment(comment_marker, opencv_version);
-				generated_values.insert(value.clone(), name.clone());
-				tpl.interpolate(&HashMap::from([
-					("doc_comment", doc_comment),
-					("duplicate_name", duplicate_name.unwrap_or_default()),
-					("name", name),
-					("value", value),
-				]))
-			})
-			.collect::<Vec<_>>();
+
+		let mut enum_consts = Vec::with_capacity(consts.len());
+		let mut from_consts = Vec::with_capacity(consts.len());
+
+		let mut generated_values = HashMap::<String, String>::with_capacity(consts.len());
+		for c in consts {
+			let name = c.rust_leafname(FishStyle::No).into_owned();
+			let value = c.value().expect("Can't get value of enum variant").to_string();
+			let duplicate_name = generated_values.get(&value).map(|s| s.as_str());
+			let (enum_const_tpl, from_const_tpl) = if duplicate_name.is_some() {
+				(&CONST_IGNORED_TPL, &FROM_CONST_IGNORED_TPL)
+			} else {
+				(&CONST_TPL, &FROM_CONST_TPL)
+			};
+			let comment_marker = if duplicate_name.is_some() {
+				"//"
+			} else {
+				"///"
+			};
+			let doc_comment = c.rendered_doc_comment(comment_marker, opencv_version);
+
+			let inter_vars = HashMap::from([
+				("name", name.as_str()),
+				("value", value.as_str()),
+				("doc_comment", &doc_comment),
+				("duplicate_name", duplicate_name.unwrap_or("")),
+			]);
+			enum_consts.push(enum_const_tpl.interpolate(&inter_vars));
+			from_consts.push(from_const_tpl.interpolate(&inter_vars));
+
+			generated_values.insert(value, name);
+		}
+
 		ENUM_TPL.interpolate(&HashMap::from([
-			("doc_comment", self.rendered_doc_comment("///", opencv_version).into()),
-			("debug", self.get_debug().into()),
-			("rust_local", self.rust_name(NameStyle::decl())),
-			("rust_full", self.rust_name(NameStyle::ref_())),
-			("consts", consts.join("").into()),
+			("rust_local", self.rust_name(NameStyle::decl()).as_ref()),
+			("rust_full", self.rust_name(NameStyle::ref_()).as_ref()),
+			("doc_comment", &self.rendered_doc_comment("///", opencv_version)),
+			("debug", &self.get_debug()),
+			("enum_consts", &enum_consts.join("")),
+			("from_consts", &from_consts.join("")),
 		]))
 	}
 }

binding-generator/src/writer/rust_native/tpl/enum/enum.tpl.rs

@@ -3,7 +3,18 @@
 #[repr(C)]
 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
 pub enum {{rust_local}} {
-	{{consts}}
+	{{enum_consts}}
+}
+
+impl TryFrom<i32> for {{rust_local}} {
+	type Error = crate::Error;
+
+	fn try_from(value: i32) -> Result<Self, Self::Error> {
+		match value {
+			{{from_consts}}
+			_ => Err(crate::Error::new(crate::core::StsBadArg, format!("Value: {value} is not valid for enum: {{rust_full}}"))),
+		}
+	}
 }
 
 opencv_type_enum! { {{rust_full}} }

binding-generator/src/writer/rust_native/tpl/enum/from_const.tpl.rs

@@ -0,0 +1,2 @@
+{{value}} => Ok(Self::{{name}}),
+

binding-generator/src/writer/rust_native/tpl/enum/from_const_ignored.tpl.rs

@@ -0,0 +1,3 @@
+// Duplicate of {{duplicate_name}}
+// {{value}} => Ok(Self::{{name}}),
+

docs/aruco.rs

@@ -60,6 +60,18 @@ pub mod aruco {
 		ARUCO_CW_TOP_LEFT_CORNER = 1,
 	}
 
+	impl TryFrom<i32> for PatternPositionType {
+		type Error = crate::Error;
+	
+		fn try_from(value: i32) -> Result<Self, Self::Error> {
+			match value {
+				0 => Ok(Self::ARUCO_CCW_CENTER),
+				1 => Ok(Self::ARUCO_CW_TOP_LEFT_CORNER),
+				_ => Err(crate::Error::new(crate::core::StsBadArg, format!("Value: {value} is not valid for enum: crate::aruco::PatternPositionType"))),
+			}
+		}
+	}
+	
 	opencv_type_enum! { crate::aruco::PatternPositionType }
 
 	/// @overload

docs/bgsegm.rs

@@ -14,6 +14,18 @@ pub mod bgsegm {
 		LSBP_CAMERA_MOTION_COMPENSATION_LK = 1,
 	}
 
+	impl TryFrom<i32> for LSBPCameraMotionCompensation {
+		type Error = crate::Error;
+	
+		fn try_from(value: i32) -> Result<Self, Self::Error> {
+			match value {
+				0 => Ok(Self::LSBP_CAMERA_MOTION_COMPENSATION_NONE),
+				1 => Ok(Self::LSBP_CAMERA_MOTION_COMPENSATION_LK),
+				_ => Err(crate::Error::new(crate::core::StsBadArg, format!("Value: {value} is not valid for enum: crate::bgsegm::LSBPCameraMotionCompensation"))),
+			}
+		}
+	}
+	
 	opencv_type_enum! { crate::bgsegm::LSBPCameraMotionCompensation }
 
 	/// Creates a CNT Background Subtractor

docs/calib3d.rs

@@ -418,6 +418,18 @@ pub mod calib3d {
 		ASYMMETRIC_GRID = 1,
 	}
 
+	impl TryFrom<i32> for CirclesGridFinderParameters_GridType {
+		type Error = crate::Error;
+	
+		fn try_from(value: i32) -> Result<Self, Self::Error> {
+			match value {
+				0 => Ok(Self::SYMMETRIC_GRID),
+				1 => Ok(Self::ASYMMETRIC_GRID),
+				_ => Err(crate::Error::new(crate::core::StsBadArg, format!("Value: {value} is not valid for enum: crate::calib3d::CirclesGridFinderParameters_GridType"))),
+			}
+		}
+	}
+	
 	opencv_type_enum! { crate::calib3d::CirclesGridFinderParameters_GridType }
 
 	#[repr(C)]
@@ -435,6 +447,21 @@ pub mod calib3d {
 		CALIB_HAND_EYE_DANIILIDIS = 4,
 	}
 
+	impl TryFrom<i32> for HandEyeCalibrationMethod {
+		type Error = crate::Error;
+	
+		fn try_from(value: i32) -> Result<Self, Self::Error> {
+			match value {
+				0 => Ok(Self::CALIB_HAND_EYE_TSAI),
+				1 => Ok(Self::CALIB_HAND_EYE_PARK),
+				2 => Ok(Self::CALIB_HAND_EYE_HORAUD),
+				3 => Ok(Self::CALIB_HAND_EYE_ANDREFF),
+				4 => Ok(Self::CALIB_HAND_EYE_DANIILIDIS),
+				_ => Err(crate::Error::new(crate::core::StsBadArg, format!("Value: {value} is not valid for enum: crate::calib3d::HandEyeCalibrationMethod"))),
+			}
+		}
+	}
+	
 	opencv_type_enum! { crate::calib3d::HandEyeCalibrationMethod }
 
 	#[repr(C)]
@@ -447,6 +474,21 @@ pub mod calib3d {
 		LOCAL_OPTIM_SIGMA = 4,
 	}
 
+	impl TryFrom<i32> for LocalOptimMethod {
+		type Error = crate::Error;
+	
+		fn try_from(value: i32) -> Result<Self, Self::Error> {
+			match value {
+				0 => Ok(Self::LOCAL_OPTIM_NULL),
+				1 => Ok(Self::LOCAL_OPTIM_INNER_LO),
+				2 => Ok(Self::LOCAL_OPTIM_INNER_AND_ITER_LO),
+				3 => Ok(Self::LOCAL_OPTIM_GC),
+				4 => Ok(Self::LOCAL_OPTIM_SIGMA),
+				_ => Err(crate::Error::new(crate::core::StsBadArg, format!("Value: {value} is not valid for enum: crate::calib3d::LocalOptimMethod"))),
+			}
+		}
+	}
+	
 	opencv_type_enum! { crate::calib3d::LocalOptimMethod }
 
 	#[repr(C)]
@@ -457,6 +499,19 @@ pub mod calib3d {
 		NEIGH_FLANN_RADIUS = 2,
 	}
 
+	impl TryFrom<i32> for NeighborSearchMethod {
+		type Error = crate::Error;
+	
+		fn try_from(value: i32) -> Result<Self, Self::Error> {
+			match value {
+				0 => Ok(Self::NEIGH_FLANN_KNN),
+				1 => Ok(Self::NEIGH_GRID),
+				2 => Ok(Self::NEIGH_FLANN_RADIUS),
+				_ => Err(crate::Error::new(crate::core::StsBadArg, format!("Value: {value} is not valid for enum: crate::calib3d::NeighborSearchMethod"))),
+			}
+		}
+	}
+	
 	opencv_type_enum! { crate::calib3d::NeighborSearchMethod }
 
 	#[repr(C)]
@@ -468,6 +523,20 @@ pub mod calib3d {
 		COV_POLISHER = 3,
 	}
 
+	impl TryFrom<i32> for PolishingMethod {
+		type Error = crate::Error;
+	
+		fn try_from(value: i32) -> Result<Self, Self::Error> {
+			match value {
+				0 => Ok(Self::NONE_POLISHER),
+				1 => Ok(Self::LSQ_POLISHER),
+				2 => Ok(Self::MAGSAC),
+				3 => Ok(Self::COV_POLISHER),
+				_ => Err(crate::Error::new(crate::core::StsBadArg, format!("Value: {value} is not valid for enum: crate::calib3d::PolishingMethod"))),
+			}
+		}
+	}
+	
 	opencv_type_enum! { crate::calib3d::PolishingMethod }
 
 	#[repr(C)]
@@ -479,6 +548,18 @@ pub mod calib3d {
 		CALIB_ROBOT_WORLD_HAND_EYE_LI = 1,
 	}
 
+	impl TryFrom<i32> for RobotWorldHandEyeCalibrationMethod {
+		type Error = crate::Error;
+	
+		fn try_from(value: i32) -> Result<Self, Self::Error> {
+			match value {
+				0 => Ok(Self::CALIB_ROBOT_WORLD_HAND_EYE_SHAH),
+				1 => Ok(Self::CALIB_ROBOT_WORLD_HAND_EYE_LI),
+				_ => Err(crate::Error::new(crate::core::StsBadArg, format!("Value: {value} is not valid for enum: crate::calib3d::RobotWorldHandEyeCalibrationMethod"))),
+			}
+		}
+	}
+	
 	opencv_type_enum! { crate::calib3d::RobotWorldHandEyeCalibrationMethod }
 
 	#[repr(C)]
@@ -490,6 +571,20 @@ pub mod calib3d {
 		SAMPLING_PROSAC = 3,
 	}
 
+	impl TryFrom<i32> for SamplingMethod {
+		type Error = crate::Error;
+	
+		fn try_from(value: i32) -> Result<Self, Self::Error> {
+			match value {
+				0 => Ok(Self::SAMPLING_UNIFORM),
+				1 => Ok(Self::SAMPLING_PROGRESSIVE_NAPSAC),
+				2 => Ok(Self::SAMPLING_NAPSAC),
+				3 => Ok(Self::SAMPLING_PROSAC),
+				_ => Err(crate::Error::new(crate::core::StsBadArg, format!("Value: {value} is not valid for enum: crate::calib3d::SamplingMethod"))),
+			}
+		}
+	}
+	
 	opencv_type_enum! { crate::calib3d::SamplingMethod }
 
 	#[repr(C)]
@@ -501,6 +596,20 @@ pub mod calib3d {
 		SCORE_METHOD_LMEDS = 3,
 	}
 
+	impl TryFrom<i32> for ScoreMethod {
+		type Error = crate::Error;
+	
+		fn try_from(value: i32) -> Result<Self, Self::Error> {
+			match value {
+				0 => Ok(Self::SCORE_METHOD_RANSAC),
+				1 => Ok(Self::SCORE_METHOD_MSAC),
+				2 => Ok(Self::SCORE_METHOD_MAGSAC),
+				3 => Ok(Self::SCORE_METHOD_LMEDS),
+				_ => Err(crate::Error::new(crate::core::StsBadArg, format!("Value: {value} is not valid for enum: crate::calib3d::ScoreMethod"))),
+			}
+		}
+	}
+	
 	opencv_type_enum! { crate::calib3d::ScoreMethod }
 
 	#[repr(C)]
@@ -546,6 +655,26 @@ pub mod calib3d {
 		SOLVEPNP_MAX_COUNT = 9,
 	}
 
+	impl TryFrom<i32> for SolvePnPMethod {
+		type Error = crate::Error;
+	
+		fn try_from(value: i32) -> Result<Self, Self::Error> {
+			match value {
+				0 => Ok(Self::SOLVEPNP_ITERATIVE),
+				1 => Ok(Self::SOLVEPNP_EPNP),
+				2 => Ok(Self::SOLVEPNP_P3P),
+				3 => Ok(Self::SOLVEPNP_DLS),
+				4 => Ok(Self::SOLVEPNP_UPNP),
+				5 => Ok(Self::SOLVEPNP_AP3P),
+				6 => Ok(Self::SOLVEPNP_IPPE),
+				7 => Ok(Self::SOLVEPNP_IPPE_SQUARE),
+				8 => Ok(Self::SOLVEPNP_SQPNP),
+				9 => Ok(Self::SOLVEPNP_MAX_COUNT),
+				_ => Err(crate::Error::new(crate::core::StsBadArg, format!("Value: {value} is not valid for enum: crate::calib3d::SolvePnPMethod"))),
+			}
+		}
+	}
+	
 	opencv_type_enum! { crate::calib3d::SolvePnPMethod }
 
 	/// cv::undistort mode
@@ -556,6 +685,18 @@ pub mod calib3d {
 		PROJ_SPHERICAL_EQRECT = 1,
 	}
 
+	impl TryFrom<i32> for UndistortTypes {
+		type Error = crate::Error;
+	
+		fn try_from(value: i32) -> Result<Self, Self::Error> {
+			match value {
+				0 => Ok(Self::PROJ_SPHERICAL_ORTHO),
+				1 => Ok(Self::PROJ_SPHERICAL_EQRECT),
+				_ => Err(crate::Error::new(crate::core::StsBadArg, format!("Value: {value} is not valid for enum: crate::calib3d::UndistortTypes"))),
+			}
+		}
+	}
+	
 	opencv_type_enum! { crate::calib3d::UndistortTypes }
 
 	pub type CirclesGridFinderParameters2 = crate::calib3d::CirclesGridFinderParameters;