{"record":{"id":"a2928998c4819a1d","repo":"bevyengine/bevy","slug":"attempted-to-call-typeregistry-register-type-con","errorCode":null,"errorMessage":"attempted to call `TypeRegistry::register_type_conversion` for type `{U}` without registering `{U}` first","messagePattern":"attempted to call `TypeRegistry::register_type_conversion` for type `(.+?)` without registering `(.+?)` first","errorType":"panic","errorClass":null,"httpStatus":null,"severity":"error","filePath":"crates/bevy_reflect/src/type_registry.rs","lineNumber":402,"sourceCode":"    /// the input value, wrapped in an `Err` variant.\n    ///\n    /// # Example\n    /// ```\n    /// # use bevy_reflect::TypeRegistry;\n    ///\n    /// let mut type_registry = TypeRegistry::default();\n    /// type_registry.register::<i32>();\n    /// type_registry.register::<String>();\n    /// type_registry.register_type_conversion::<i32, String, _>(|n| Ok(n.to_string()));\n    /// ```\n    pub fn register_type_conversion<T, U, F>(&mut self, function: F)\n    where\n        T: Reflect + TypePath,\n        U: Reflect + TypePath,\n        F: Fn(T) -> Result<U, T> + Clone + Send + Sync + 'static,\n    {\n        let data = self.get_mut(TypeId::of::<U>()).unwrap_or_else(|| {\n            panic!(\n                \"attempted to call `TypeRegistry::register_type_conversion` for type `{U}` without registering `{U}` first\",\n                U = U::type_path(),\n            )\n        });\n        data.get_or_insert_data_with(ReflectConvert::default)\n            .register_type_conversion(function);\n    }\n\n    /// Given types T and U, where `U: From<T>`, registers that conversion with\n    /// the reflection system.\n    ///\n    /// # Example\n    /// ```\n    /// # use bevy_reflect::TypeRegistry;\n    ///\n    /// let mut type_registry = TypeRegistry::default();\n    /// type_registry.register::<u8>();\n    /// type_registry.register::<u32>();","sourceCodeStart":384,"sourceCodeEnd":420,"githubUrl":"https://github.com/bevyengine/bevy/blob/396ca727080776bd313bb892423b7d94e03b81b4/crates/bevy_reflect/src/type_registry.rs#L384-L420","documentation":"Panic in TypeRegistry::register_type_conversion: the target type U of the conversion was not registered in the registry before calling this method. Register both T and U (e.g. registry.register::<U>()) before registering the conversion function.","triggerScenarios":"Thrown at crates/bevy_reflect/src/type_registry.rs:402 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Call registry.register::<U>() before register_type_conversion"],"exampleFix":null,"handlingStrategy":"validation","validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"396ca727080776bd313bb892423b7d94e03b81b4","analyzedAt":"2026-08-20T16:12:39.808Z","contentChangedAt":"2026-08-20T16:12:39.808Z","schemaVersion":2},"datasetVersion":"2026-09-14T05:17:10.506Z"}