{
  "id": "rust/e0277-try-from-impl-not-satisfied",
  "signature": "error[E0277]: the trait bound `T: From<U>` is not satisfied",
  "signature_zh": "错误[E0277]：未满足特征约束 `T: From<U>`",
  "regex": "error\\[E0277\\]: the trait bound `.*: From<.*>` is not satisfied",
  "domain": "rust",
  "category": "type_error",
  "subcategory": null,
  "root_cause": "A type conversion via `From` or `TryFrom` trait is attempted but the destination type does not implement the required conversion for the source type.",
  "root_cause_type": "generic",
  "root_cause_zh": "尝试通过 `From` 或 `TryFrom` 特征进行类型转换，但目标类型未实现针对源类型的必要转换。",
  "versions": [
    {
      "version": "rustc 1.75.0",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "rustc 1.76.0",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "rustc 1.77.0",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "",
      "why_fails": "The `From` trait is already in the prelude; importing it doesn't add implementations.",
      "fail_rate": 0.95,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "The `as` keyword only works for primitive numeric types or raw pointer conversions, not for custom types or complex conversions.",
      "fail_rate": 0.85,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "`From` cannot be derived automatically for arbitrary types; you need a manual `impl From<U> for T` block.",
      "fail_rate": 0.9,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "Implement the `From` trait for the target type: `impl From<SourceType> for TargetType { fn from(value: SourceType) -> Self { TargetType { /* conversion logic */ } } }`",
      "success_rate": 0.95,
      "how": "Implement the `From` trait for the target type: `impl From<SourceType> for TargetType { fn from(value: SourceType) -> Self { TargetType { /* conversion logic */ } } }`",
      "condition": "",
      "sources": []
    },
    {
      "action": "Use an alternative conversion method like `.into()` if the source type already implements `Into<TargetType>` (which auto-provides `From`), or use `.try_into()` with `TryFrom` for fallible conversions.",
      "success_rate": 0.85,
      "how": "Use an alternative conversion method like `.into()` if the source type already implements `Into<TargetType>` (which auto-provides `From`), or use `.try_into()` with `TryFrom` for fallible conversions.",
      "condition": "",
      "sources": []
    },
    {
      "action": "If the conversion is infallible, use `From`; if fallible, switch to `TryFrom` and handle the error: `impl TryFrom<SourceType> for TargetType { type Error = ConversionError; fn try_from(value: SourceType) -> Result<Self, Self::Error> { ... } }`",
      "success_rate": 0.9,
      "how": "If the conversion is infallible, use `From`; if fallible, switch to `TryFrom` and handle the error: `impl TryFrom<SourceType> for TargetType { type Error = ConversionError; fn try_from(value: SourceType) -> Result<Self, Self::Error> { ... } }`",
      "condition": "",
      "sources": []
    }
  ],
  "workarounds_zh": [
    "Implement the `From` trait for the target type: `impl From<SourceType> for TargetType { fn from(value: SourceType) -> Self { TargetType { /* conversion logic */ } } }`",
    "Use an alternative conversion method like `.into()` if the source type already implements `Into<TargetType>` (which auto-provides `From`), or use `.try_into()` with `TryFrom` for fallible conversions.",
    "If the conversion is infallible, use `From`; if fallible, switch to `TryFrom` and handle the error: `impl TryFrom<SourceType> for TargetType { type Error = ConversionError; fn try_from(value: SourceType) -> Result<Self, Self::Error> { ... } }`"
  ],
  "transition_graph": {
    "leads_to": [],
    "preceded_by": [],
    "frequently_confused_with": []
  },
  "official_doc_url": "https://doc.rust-lang.org/error_codes/E0277.html",
  "official_doc_section": null,
  "error_code": "E0277",
  "verification_tier": "ai_generated",
  "confidence": 0.88,
  "fix_success_rate": 0.9,
  "resolvable": "true",
  "first_seen": "2023-08-15",
  "last_confirmed": "2024-06-01",
  "last_updated": "2024-06-01",
  "evidence_count": 1,
  "tags": [],
  "locale": "en",
  "aliases": []
}