Enum CodecError 

pub enum CodecError {
    Empty,
    Version {
        expected: u8,
        actual: u8,
    },
    Encode(Error),
    Decode(Error),
    TrailingBytes {
        extra: usize,
    },
    VersionUnsupported {
        min: u8,
        max: u8,
        actual: u8,
    },
    NotRepresentable {
        version: u8,
    },
}

Failure modes of the version-prefixed postcard codec.

Encode and Decode are kept distinct so a caller can tell which direction failed; both carry the underlying postcard::Error as the error source rather than via a From conversion, so a stray ? on a postcard result never silently becomes a CodecError.

Variants

Empty

The payload had no leading version byte (it was empty).

Version

The leading version byte did not match the version the reader expected. A stale reader hits this instead of misdecoding old bytes against a new struct layout.

Fields

expected: u8

actual: u8

Encode(Error)

postcard failed to serialize the value.

Decode(Error)

postcard failed to deserialize the framed body.

TrailingBytes

The body decoded successfully but extra bytes remained unconsumed. For a versioned on-disk format this signals corruption — e.g. a partial overwrite that left stale tail bytes — rather than a clean record.

Fields

extra: usize

VersionUnsupported

The leading version byte was outside the reader’s supported range [min, max]. Distinct from CodecError::Version (which a single-version reader returns); a multi-version reader uses this to fail loudly on a version it has no parser for.

Fields

min: u8

max: u8

actual: u8

NotRepresentable

Down-conversion was asked to encode state not representable at version (a feature-gate violation: a field/behavior introduced at a later version is set while encoding an older layout). Fail-loud rather than silently dropping the value.

Fields

version: u8

Trait Implementations

impl Debug for CodecError

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

Formats the value using the given formatter.

impl Display for CodecError

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

Formats the value using the given formatter.

impl Error for CodecError

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.