Enum mycelium_util::io::ErrorKind

#[non_exhaustive]
pub enum ErrorKind {
    NotFound,
    PermissionDenied,
    ConnectionRefused,
    ConnectionReset,
    ConnectionAborted,
    NotConnected,
    AddrInUse,
    AddrNotAvailable,
    BrokenPipe,
    AlreadyExists,
    WouldBlock,
    InvalidInput,
    InvalidData,
    TimedOut,
    WriteZero,
    Interrupted,
    Other,
    UnexpectedEof,
}

A list specifying general categories of I/O error.

This list is intended to grow over time and it is not recommended to exhaustively match against it.

It is used with the io::Error type.

Handling errors and matching on ErrorKind

In application code, use match for the ErrorKind values you are expecting; use _ to match “all other errors”.

In comprehensive and thorough tests that want to verify that a test doesn’t return any known incorrect error kind, you may want to cut-and-paste the current full list of errors from here into your test code, and then match _ as the correct case. This seems counterintuitive, but it will make your tests more robust. In particular, if you want to verify that your code does produce an unrecognized error kind, the robust solution is to check for all the recognized error kinds and fail in those cases.

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.

NotFound

An entity was not found, often a file.

PermissionDenied

The operation lacked the necessary privileges to complete.

ConnectionRefused

The connection was refused by the remote server.

ConnectionReset

The connection was reset by the remote server.

ConnectionAborted

The connection was aborted (terminated) by the remote server.

NotConnected

The network operation failed because it was not connected yet.

AddrInUse

A socket address could not be bound because the address is already in use elsewhere.

AddrNotAvailable

A nonexistent interface was requested or the requested address was not local.

BrokenPipe

The operation failed because a pipe was closed.

AlreadyExists

An entity already exists, often a file.

WouldBlock

The operation needs to block to complete, but the blocking operation was requested to not occur.

InvalidInput

A parameter was incorrect.

InvalidData

Data not valid for the operation were encountered.

Unlike InvalidInput, this typically means that the operation parameters were valid, however the error was caused by malformed input data.

For example, a function that reads a file into a string will error with InvalidData if the file’s contents are not valid UTF-8.

TimedOut

The I/O operation’s timeout expired, causing it to be canceled.

WriteZero

An error returned when an operation could not be completed because a call to write returned Ok(0).

This typically means that an operation could only succeed if it wrote a particular number of bytes but only a smaller number of bytes could be written.

Interrupted

This operation was interrupted.

Interrupted operations can typically be retried.

Other

Any I/O error not part of this list.

UnexpectedEof

An error returned when an operation could not be completed because an “end of file” was reached prematurely.

This typically means that an operation could only succeed if it read a particular number of bytes but only a smaller number of bytes could be read.

Trait Implementations

impl Clone for ErrorKind

fn clone(&self) -> ErrorKind

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for ErrorKind

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

Formats the value using the given formatter.

impl From<ErrorKind> for Error

fn from(kind: ErrorKind) -> Self

Converts to this type from the input type.

impl Hash for ErrorKind

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for ErrorKind

fn cmp(&self, other: &ErrorKind) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl PartialEq for ErrorKind

fn eq(&self, other: &ErrorKind) -> 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 PartialOrd for ErrorKind

fn partial_cmp(&self, other: &ErrorKind) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Copy for ErrorKind

impl Eq for ErrorKind

impl StructuralPartialEq for ErrorKind