Enum PresentError 

#[non_exhaustive]
pub enum PresentError {
    Busy,
    NoHost,
    Unsupported,
    InvalidSpec(String),
    Platform(String),
}

Why a presentation could not be shown or did not complete.

thiserror-derived per docs/CODE_STANDARDS.md: callers match on the variant.

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.

Busy

Another presentation is live — one at a time, process-wide. Recover by resolving it: take it down through its PresentationHandle with dismiss, or drop its Presentation future — either frees the slot. A refusal logs the live presentation’s generation and how long it has been held (where the target has a monotonic clock); see docs/LIMITATIONS.md’s native-widgets-alert-busy-slot-unobserved-host-teardown for the case where a live presentation outlives an unobserved host teardown.

NoHost

No host to present over: no resumed Android Activity, no iOS window scene with a root view controller, no macOS key/main window.

Unsupported

This platform has no native presentation of this kind.

InvalidSpec(String)

The request broke a submit-time rule (see AlertSpec / SheetSpec::validate).

Platform(String)

A platform failure not covered above (a JNI/Objective-C error, an arm that ended without an outcome).

Trait Implementations

impl Clone for PresentError

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PresentError

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

Formats the value using the given formatter.

impl Display for PresentError

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

Formats the value using the given formatter.

impl Eq for PresentError

impl Error for PresentError

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 PartialEq for PresentError

fn eq(&self, other: &Self) -> bool

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for PresentError