Struct Debug

pub struct Debug<E>(pub E);

Debug prints the internal value before responding with a 500 error.

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.

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::io::{self, Read};

use rocket::Data;
use rocket::response::Debug;

#[post("/", format = "plain", data = "<data>")]
fn post(data: Data) -> Result<String, Debug<io::Error>> {
    let mut name = String::with_capacity(32);
    data.open().take(32).read_to_string(&mut name)?;
    Ok(name)
}

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)
}

Tuple Fields

0: E

Trait Implementations

impl<E: Debug> Debug for Debug<E>

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

Formats the value using the given formatter.

impl<E> From<E> for Debug<E>

fn from(e: E) -> Self

Converts to this type from the input type.

impl<'r, E: Debug> Responder<'r> for Debug<E>

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

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