Type Alias TryReadError

pub type TryReadError<Src, Dst: ?Sized + TryFromBytes> = ConvertError<Infallible, SizeError<Src, Dst>, ValidityError<Src, Dst>>;

The error type of fallible read-conversions.

Fallible read-conversions, like TryFromBytes::try_read_from_bytes may emit size and validity errors, but not alignment errors.

Aliased Type

enum TryReadError<Src, Dst: ?Sized + TryFromBytes> {
    Alignment(Infallible),
    Size(SizeError<Src, Dst>),
    Validity(ValidityError<Src, Dst>),
}

Variants

Alignment(Infallible)

The conversion source was improperly aligned.

Size(SizeError<Src, Dst>)

The conversion source was of incorrect size.

Validity(ValidityError<Src, Dst>)

The conversion source contained invalid data.

Implementations

impl<Src, Dst: ?Sized + TryFromBytes> TryReadError<Src, Dst>

pub fn into_src(self) -> Src

Produces the source underlying the failed conversion.

pub fn map_src<NewSrc>( self, f: impl FnOnce(Src) -> NewSrc, ) -> TryReadError<NewSrc, Dst>

Maps the source value associated with the conversion error.

This can help mitigate issues with Send, Sync and 'static bounds.

Examples

use core::num::NonZeroU32;
use zerocopy::*;

let source: [u8; 3] = [0, 0, 0];

// Try to read a `NonZeroU32` from `source`.
let maybe_u32: Result<NonZeroU32, TryReadError<&[u8], NonZeroU32>>
    = NonZeroU32::try_read_from_bytes(&source[..]);

// Map the error's source to its size.
let maybe_u32: Result<NonZeroU32, TryReadError<usize, NonZeroU32>> =
    maybe_u32.map_err(|err| {
        err.map_src(|src| src.len())
    });

Trait Implementations

impl<A: Debug, S: Debug, V: Debug> Debug for ConvertError<A, S, V>

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

Formats the value using the given formatter.

impl<A: Display, S: Display, V: Display> Display for ConvertError<A, S, V>

Produces a human-readable error message.

The message differs between debug and release builds. When debug_assertions are enabled, this message is verbose and includes potentially sensitive information.

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

Formats the value using the given formatter.

impl<A, S, V> Error for ConvertError<A, S, V>

where A: Display + Debug, S: Display + Debug, V: Display + Debug,

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<Src, Dst: ?Sized + Unaligned, S, V> From<ConvertError<AlignmentError<Src, Dst>, S, V>> for ConvertError<Infallible, S, V>

fn from( err: ConvertError<AlignmentError<Src, Dst>, S, V>, ) -> ConvertError<Infallible, S, V>

Infallibly discards the alignment error from this ConvertError since Dst is unaligned.

Since Dst: Unaligned, it is impossible to encounter an alignment error. This method permits discarding that alignment error infallibly and replacing it with Infallible.

Examples

use core::convert::Infallible;
use zerocopy::*;

#[derive(TryFromBytes, KnownLayout, Unaligned, Immutable)]
#[repr(C, packed)]
struct Bools {
    one: bool,
    two: bool,
    many: [bool],
}

impl Bools {
    fn parse(bytes: &[u8]) -> Result<&Bools, AlignedTryCastError<&[u8], Bools>> {
        // Since `Bools: Unaligned`, we can infallibly discard
        // the alignment error.
        Bools::try_ref_from_bytes(bytes).map_err(Into::into)
    }
}

impl<Src, Dst: ?Sized, A, V> From<SizeError<Src, Dst>> for ConvertError<A, SizeError<Src, Dst>, V>

fn from(err: SizeError<Src, Dst>) -> Self

Converts to this type from the input type.

impl<Src, Dst: ?Sized + TryFromBytes, A, S> From<ValidityError<Src, Dst>> for ConvertError<A, S, ValidityError<Src, Dst>>

fn from(err: ValidityError<Src, Dst>) -> Self

Converts to this type from the input type.

impl<A: PartialEq, S: PartialEq, V: PartialEq> PartialEq for ConvertError<A, S, V>

fn eq(&self, other: &ConvertError<A, S, V>) -> 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<A: Eq, S: Eq, V: Eq> Eq for ConvertError<A, S, V>

impl<A, S, V> StructuralPartialEq for ConvertError<A, S, V>