Struct rand_core::Error

pub struct Error { /* private fields */ }

Error type of random number generators

In order to be compatible with std and no_std, this type has two possible implementations: with std a boxed Error trait object is stored, while with no_std we merely store an error code.

Implementations

impl Error

pub const CUSTOM_START: u32 = 3_221_225_472u32

Codes at or above this point can be used by users to define their own custom errors.

This has a fixed value of (1 << 31) + (1 << 30) = 0xC000_0000, therefore the number of values available for custom codes is 1 << 30.

This is identical to getrandom::Error::CUSTOM_START.

pub const INTERNAL_START: u32 = 2_147_483_648u32

Codes below this point represent OS Errors (i.e. positive i32 values). Codes at or above this point, but below Error::CUSTOM_START are reserved for use by the rand and getrandom crates.

This is identical to getrandom::Error::INTERNAL_START.

pub fn new<E>(err: E) -> Self

where E: Into<Box<dyn Error + Send + Sync + 'static>>,

Construct from any type supporting std::error::Error

Available only when configured with std.

See also From<NonZeroU32>, which is available with and without std.

pub fn inner(&self) -> &(dyn Error + Send + Sync + 'static)

Reference the inner error (std only)

When configured with std, this is a trivial operation and never panics. Without std, this method is simply unavailable.

pub fn take_inner(self) -> Box<dyn Error + Send + Sync + 'static>

Unwrap the inner error (std only)

When configured with std, this is a trivial operation and never panics. Without std, this method is simply unavailable.

pub fn raw_os_error(&self) -> Option<i32>

Extract the raw OS error code (if this error came from the OS)

This method is identical to std::io::Error::raw_os_error(), except that it works in no_std contexts. If this method returns None, the error value can still be formatted via the Display implementation.

pub fn code(&self) -> Option<NonZeroU32>

Retrieve the error code, if any.

If this Error was constructed via From<NonZeroU32>, then this method will return this NonZeroU32 code (for no_std this is always the case). Otherwise, this method will return None.

Trait Implementations

impl Debug for Error

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

Formats the value using the given formatter.

impl Display for Error

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

Formats the value using the given formatter.

impl Error for Error

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 From<Error> for Error

fn from(error: Error) -> Self

Converts to this type from the input type.

impl From<Error> for Error

fn from(error: Error) -> Self

Converts to this type from the input type.

impl From<NonZero<u32>> for Error

fn from(code: NonZeroU32) -> Self

Converts to this type from the input type.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 16 bytes