1.0.0[−][src]Struct std::io::Error
The error type for I/O operations of the Read, Write, Seek, and
associated traits.
Errors mostly originate from the underlying OS, but custom instances of
Error can be created with crafted error messages and a particular value of
ErrorKind.
Methods
impl Error[src]
pub fn new<E>(kind: ErrorKind, error: E) -> Error where
E: Into<Box<dyn Error + Send + Sync>>, [src]
E: Into<Box<dyn Error + Send + Sync>>,
Creates a new I/O error from a known kind of error as well as an arbitrary error payload.
This function is used to generically create I/O errors which do not
originate from the OS itself. The error argument is an arbitrary
payload which will be contained in this Error.
Examples
use std::io::{Error, ErrorKind}; // errors can be created from strings let custom_error = Error::new(ErrorKind::Other, "oh no!"); // errors can also be created from other errors let custom_error2 = Error::new(ErrorKind::Interrupted, custom_error);Run
pub fn last_os_error() -> Error[src]
Returns an error representing the last OS error which occurred.
This function reads the value of errno for the target platform (e.g.
GetLastError on Windows) and will return a corresponding instance of
Error for the error code.
Examples
use std::io::Error; println!("last OS error: {:?}", Error::last_os_error());Run
pub fn from_raw_os_error(code: i32) -> Error[src]
Creates a new instance of an Error from a particular OS error code.
Examples
On Linux:
use std::io; let error = io::Error::from_raw_os_error(22); assert_eq!(error.kind(), io::ErrorKind::InvalidInput);Run
On Windows:
use std::io; let error = io::Error::from_raw_os_error(10022); assert_eq!(error.kind(), io::ErrorKind::InvalidInput);Run
pub fn raw_os_error(&self) -> Option<i32>[src]
Returns the OS error that this error represents (if any).
If this Error was constructed via last_os_error or
from_raw_os_error, then this function will return Some, otherwise
it will return None.
Examples
use std::io::{Error, ErrorKind}; fn print_os_error(err: &Error) { if let Some(raw_os_err) = err.raw_os_error() { println!("raw OS error: {:?}", raw_os_err); } else { println!("Not an OS error"); } } fn main() { // Will print "raw OS error: ...". print_os_error(&Error::last_os_error()); // Will print "Not an OS error". print_os_error(&Error::new(ErrorKind::Other, "oh no!")); }Run
pub fn get_ref(&self) -> Option<&(dyn Error + Send + Sync + 'static)>1.3.0[src]
Returns a reference to the inner error wrapped by this error (if any).
If this Error was constructed via new then this function will
return Some, otherwise it will return None.
Examples
use std::io::{Error, ErrorKind}; fn print_error(err: &Error) { if let Some(inner_err) = err.get_ref() { println!("Inner error: {:?}", inner_err); } else { println!("No inner error"); } } fn main() { // Will print "No inner error". print_error(&Error::last_os_error()); // Will print "Inner error: ...". print_error(&Error::new(ErrorKind::Other, "oh no!")); }Run
pub fn get_mut(&mut self) -> Option<&mut (dyn Error + Send + Sync + 'static)>1.3.0[src]
Returns a mutable reference to the inner error wrapped by this error (if any).
If this Error was constructed via new then this function will
return Some, otherwise it will return None.
Examples
use std::io::{Error, ErrorKind}; use std::{error, fmt}; use std::fmt::Display; #[derive(Debug)] struct MyError { v: String, } impl MyError { fn new() -> MyError { MyError { v: "oh no!".to_string() } } fn change_message(&mut self, new_message: &str) { self.v = new_message.to_string(); } } impl error::Error for MyError { fn description(&self) -> &str { &self.v } } impl Display for MyError { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { write!(f, "MyError: {}", &self.v) } } fn change_error(mut err: Error) -> Error { if let Some(inner_err) = err.get_mut() { inner_err.downcast_mut::<MyError>().unwrap().change_message("I've been changed!"); } err } fn print_error(err: &Error) { if let Some(inner_err) = err.get_ref() { println!("Inner error: {}", inner_err); } else { println!("No inner error"); } } fn main() { // Will print "No inner error". print_error(&change_error(Error::last_os_error())); // Will print "Inner error: ...". print_error(&change_error(Error::new(ErrorKind::Other, MyError::new()))); }Run
pub fn into_inner(self) -> Option<Box<dyn Error + Send + Sync>>1.3.0[src]
Consumes the Error, returning its inner error (if any).
If this Error was constructed via new then this function will
return Some, otherwise it will return None.
Examples
use std::io::{Error, ErrorKind}; fn print_error(err: Error) { if let Some(inner_err) = err.into_inner() { println!("Inner error: {}", inner_err); } else { println!("No inner error"); } } fn main() { // Will print "No inner error". print_error(Error::last_os_error()); // Will print "Inner error: ...". print_error(Error::new(ErrorKind::Other, "oh no!")); }Run
pub fn kind(&self) -> ErrorKind[src]
Returns the corresponding ErrorKind for this error.
Examples
use std::io::{Error, ErrorKind}; fn print_error(err: Error) { println!("{:?}", err.kind()); } fn main() { // Will print "No inner error". print_error(Error::last_os_error()); // Will print "Inner error: ...". print_error(Error::new(ErrorKind::AddrInUse, "oh no!")); }Run
Trait Implementations
impl Error for Error[src]
fn description(&self) -> &str[src]
fn cause(&self) -> Option<&dyn Error>[src]
fn source(&self) -> Option<&(dyn Error + 'static)>[src]
impl Display for Error[src]
impl Debug for Error[src]
impl From<NulError> for Error[src]
impl<W> From<IntoInnerError<W>> for Error[src]
fn from(iie: IntoInnerError<W>) -> Error[src]
impl From<ErrorKind> for Error1.14.0[src]
Intended for use for errors not exposed to the user, where allocating onto the heap (for normal construction via Error::new) is too costly.
Auto Trait Implementations
Blanket Implementations
impl<T> From<T> for T[src]
impl<T, U> TryFrom<U> for T where
U: Into<T>, [src]
U: Into<T>,
type Error = Infallible
The type returned in the event of a conversion error.
fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>[src]
impl<T, U> Into<U> for T where
U: From<T>, [src]
U: From<T>,
impl<T, U> TryInto<U> for T where
U: TryFrom<T>, [src]
U: TryFrom<T>,
type Error = <U as TryFrom<T>>::Error
The type returned in the event of a conversion error.
fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>[src]
impl<T> Borrow<T> for T where
T: ?Sized, [src]
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized, [src]
T: ?Sized,
ⓘImportant traits for &'_ mut Ffn borrow_mut(&mut self) -> &mut T[src]
impl<T> Any for T where
T: 'static + ?Sized, [src]
T: 'static + ?Sized,
impl<T> ToString for T where
T: Display + ?Sized, [src]
T: Display + ?Sized,