Struct rocket::response::Debug[][src]

pub struct Debug<E>(pub E);
Expand description

Debug prints the internal value before forwarding to the 500 error catcher.

This value exists primarily to allow handler return types that would not otherwise implement Responder. It is typically used in conjunction with Result<T, E> where E implements Debug but not Responder.

Note that because of it’s common use as an error value, std::io::Error does implement Responder. As a result, a std::io::Result<T> can be returned directly without the need for Debug:

use std::io;

use rocket::fs::NamedFile;

#[get("/")]
async fn index() -> io::Result<NamedFile> {
    NamedFile::open("index.html").await
}

Example

Because of the generic From<E> implementation for Debug<E>, conversions from Result<T, E> to Result<T, Debug<E>> through ? occur automatically:

use std::string::FromUtf8Error;

use rocket::response::Debug;

#[get("/")]
fn rand_str() -> Result<String, Debug<FromUtf8Error>> {
    let bytes: Vec<u8> = random_bytes();
    Ok(String::from_utf8(bytes)?)
}

It is also possible to map the error directly to Debug via Result::map_err():

use std::string::FromUtf8Error;

use rocket::response::Debug;

#[get("/")]
fn rand_str() -> Result<String, Debug<FromUtf8Error>> {
    let bytes: Vec<u8> = random_bytes();
    String::from_utf8(bytes).map_err(Debug)
}

Trait Implementations

impl<E: Debug> Debug for Debug<E>[src]

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

Formats the value using the given formatter. Read more

impl<E> From<E> for Debug<E>[src]

fn from(e: E) -> Self[src]

Performs the conversion.

impl<'r, E: Debug> Responder<'r, 'static> for Debug<E>[src]

fn respond_to(self, _: &'r Request<'_>) -> Result<'static>[src]

Returns Ok if a Response could be generated successfully. Otherwise, returns an Err with a failing Status. Read more

impl<T> Sentinel for Debug<T>[src]

A sentinel that never aborts. The Responder impl for Debug will never be called, so it’s okay to not abort for failing T: Sentinel.

fn abort(_: &Rocket<Ignite>) -> bool[src]

Returns true if launch should be aborted and false otherwise.

Auto Trait Implementations

impl<E> RefUnwindSafe for Debug<E> where
    E: RefUnwindSafe

impl<E> Send for Debug<E> where
    E: Send

impl<E> Sync for Debug<E> where
    E: Sync

impl<E> Unpin for Debug<E> where
    E: Unpin

impl<E> UnwindSafe for Debug<E> where
    E: UnwindSafe

Blanket Implementations

impl<T> Any for T where
    T: 'static + ?Sized
[src]

pub fn type_id(&self) -> TypeId[src]

Gets the TypeId of self. Read more

impl<T> Borrow<T> for T where
    T: ?Sized
[src]

pub fn borrow(&self) -> &T[src]

Immutably borrows from an owned value. Read more

impl<T> BorrowMut<T> for T where
    T: ?Sized
[src]

pub fn borrow_mut(&mut self) -> &mut T[src]

Mutably borrows from an owned value. Read more

impl<T> From<!> for T[src]

pub fn from(t: !) -> T[src]

Performs the conversion.

impl<T> From<T> for T[src]

pub fn from(t: T) -> T[src]

Performs the conversion.

impl<T> Instrument for T[src]

fn instrument(self, span: Span) -> Instrumented<Self>[src]

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more

fn in_current_span(self) -> Instrumented<Self>[src]

Instruments this type with the current Span, returning an Instrumented wrapper. Read more

impl<T, U> Into<U> for T where
    U: From<T>, 
[src]

pub fn into(self) -> U[src]

Performs the conversion.

impl<T> IntoCollection<T> for T

pub fn into_collection<A>(self) -> SmallVec<A> where
    A: Array<Item = T>, 

Converts self into a collection.

pub fn mapped<U, F, A>(self, f: F) -> SmallVec<A> where
    F: FnMut(T) -> U,
    A: Array<Item = U>, 

impl<T> Same<T> for T

type Output = T

Should always be Self

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 
[src]

type Error = Infallible

The type returned in the event of a conversion error.

pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>[src]

Performs the conversion.

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, 
[src]

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.

pub fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>[src]

Performs the conversion.

impl<V, T> VZip<V> for T where
    V: MultiLane<T>, 

pub fn vzip(self) -> V