pub struct Error { /* private fields */ }
Expand description
An error that occurs during launch.
An Error
is returned by launch()
when launching an
application fails or, more rarely, when the runtime fails after lauching.
Panics
A value of this type panics if it is dropped without first being inspected.
An inspection occurs when any method is called. For instance, if
println!("Error: {}", e)
is called, where e: Error
, the Display::fmt
method being called by println!
results in e
being marked as inspected;
a subsequent drop
of the value will not result in a panic. The following
snippet illustrates this:
if let Err(error) = rocket::build().launch().await {
// This println "inspects" the error.
println!("Launch failed! Error: {}", error);
// This call to drop (explicit here for demonstration) will do nothing.
drop(error);
}
When a value of this type panics, the corresponding error message is pretty printed to the console. The following illustrates this:
let error = rocket::build().launch().await;
// This call to drop (explicit here for demonstration) will result in
// `error` being pretty-printed to the console along with a `panic!`.
drop(error);
Usage
An Error
value should usually be allowed to drop
without inspection.
There are at least two exceptions:
-
If you are writing a library or high-level application on-top of Rocket, you likely want to inspect the value before it drops to avoid a Rocket-specific
panic!
. This typically means simply printing the value. -
You want to display your own error messages.
Implementations
sourceimpl Error
impl Error
sourcepub fn kind(&self) -> &ErrorKind
pub fn kind(&self) -> &ErrorKind
Retrieve the kind
of the launch error.
Example
use rocket::error::ErrorKind;
if let Err(error) = rocket::build().launch().await {
match error.kind() {
ErrorKind::Io(e) => println!("found an i/o launch error: {}", e),
e => println!("something else happened: {}", e)
}
}
Trait Implementations
sourceimpl Error for Error
impl Error for Error
1.30.0 · sourcefn source(&self) -> Option<&(dyn Error + 'static)>
fn source(&self) -> Option<&(dyn Error + 'static)>
The lower-level source of this error, if any. Read more
sourcefn backtrace(&self) -> Option<&Backtrace>
fn backtrace(&self) -> Option<&Backtrace>
backtrace
)Returns a stack backtrace, if available, of where this error occurred. Read more
1.0.0 · sourcefn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
Auto Trait Implementations
impl !RefUnwindSafe for Error
impl Send for Error
impl Sync for Error
impl Unpin for Error
impl !UnwindSafe for Error
Blanket Implementations
impl<'a, T> AsTaggedExplicit<'a> for T where
T: 'a,
impl<'a, T> AsTaggedExplicit<'a> for T where
T: 'a,
fn explicit(self, class: Class, tag: u32) -> TaggedParser<'a, Explicit, Self>
impl<'a, T> AsTaggedImplicit<'a> for T where
T: 'a,
impl<'a, T> AsTaggedImplicit<'a> for T where
T: 'a,
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
sourceimpl<T> Instrument for T
impl<T> Instrument for T
sourcefn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
sourcefn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
sourceimpl<T> IntoCollection<T> for T
impl<T> IntoCollection<T> for T
sourcefn into_collection<A>(self) -> SmallVec<A> where
A: Array<Item = T>,
fn into_collection<A>(self) -> SmallVec<A> where
A: Array<Item = T>,
Converts self
into a collection.
fn mapped<U, F, A>(self, f: F) -> SmallVec<A> where
F: FnMut(T) -> U,
A: Array<Item = U>,
impl<V, T> VZip<V> for T where
V: MultiLane<T>,
impl<V, T> VZip<V> for T where
V: MultiLane<T>,
fn vzip(self) -> V
sourceimpl<T> WithSubscriber for T
impl<T> WithSubscriber for T
sourcefn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self> where
S: Into<Dispatch>,
fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self> where
S: Into<Dispatch>,
Attaches the provided Subscriber
to this type, returning a
WithDispatch
wrapper. Read more
sourcefn with_current_subscriber(self) -> WithDispatch<Self>
fn with_current_subscriber(self) -> WithDispatch<Self>
Attaches the current default Subscriber
to this type, returning a
WithDispatch
wrapper. Read more