Enum MergePatchError 

#[non_exhaustive]
pub enum MergePatchError {
    DepthExceeded,
}

Error returned by json_merge_patch when a patch cannot be applied.

Marked #[non_exhaustive] so future RFC 7396 failure modes (e.g. a size cap in addition to the depth cap) can be added without an API break.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

DepthExceeded

The patch nests deeper than the crate’s MAX_MERGE_PATCH_DEPTH DoS-guard cap.

Callers SHOULD map this to SetError with SetErrorType::InvalidPatch and MUST discard any partially-mutated target rather than persisting it — see the contract on json_merge_patch.

Why no reached / max payload (bd:JMAP-jfia.39)

The variant is intentionally unit-shaped. The cap value is available in the Display impl (which interpolates MAX_MERGE_PATCH_DEPTH) for log-line and user-message use. A typed payload { reached: usize, max: usize } was considered and rejected for now because (a) no current consumer in the workspace destructures the reached depth or the cap programmatically — all 6 call sites map to SetErrorType::InvalidPatch with a generic description; and (b) changing a unit variant to a struct variant is a breaking pattern-match change even on a #[non_exhaustive] enum (the existing if let Err(MergePatchError::DepthExceeded) pattern would stop compiling). If a future consumer needs programmatic access to the depth, the additive evolution is to add a new variant alongside (e.g. DepthExceededDetail { reached: usize, max: usize }) and emit the new variant from json_merge_patch. The unit variant would then become unreachable but remain valid pattern syntax for any pinned-version consumer.

Trait Implementations

impl Clone for MergePatchError

fn clone(&self) -> MergePatchError

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for MergePatchError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for MergePatchError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for MergePatchError

impl Error for MergePatchError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl PartialEq for MergePatchError

fn eq(&self, other: &MergePatchError) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for MergePatchError