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Enum rocket::outcome::Outcome

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pub enum Outcome<S, E, F> {
    Success(S),
    Failure(E),
    Forward(F),
}
Expand description

An enum representing success (Success), failure (Failure), or forwarding (Forward).

See the top level documentation for detailed information.

Variants

Success(S)

Contains the success value.

Failure(E)

Contains the failure error value.

Forward(F)

Contains the value to forward on.

Implementations

Unwraps the Outcome, yielding the contents of a Success.

Panics

Panics if the value is not Success.

Examples
let x: Outcome<i32, &str, usize> = Success(10);
assert_eq!(x.unwrap(), 10);

Unwraps the Outcome, yielding the contents of a Success.

Panics

If the value is not Success, panics with the given message.

Examples
let x: Outcome<i32, &str, usize> = Success(10);
assert_eq!(x.expect("success value"), 10);

Return true if this Outcome is a Success.

Examples
let x: Outcome<i32, &str, usize> = Success(10);
assert_eq!(x.is_success(), true);

let x: Outcome<i32, &str, usize> = Failure("Hi! I'm an error.");
assert_eq!(x.is_success(), false);

let x: Outcome<i32, &str, usize> = Forward(25);
assert_eq!(x.is_success(), false);

Return true if this Outcome is a Failure.

Examples
let x: Outcome<i32, &str, usize> = Success(10);
assert_eq!(x.is_failure(), false);

let x: Outcome<i32, &str, usize> = Failure("Hi! I'm an error.");
assert_eq!(x.is_failure(), true);

let x: Outcome<i32, &str, usize> = Forward(25);
assert_eq!(x.is_failure(), false);

Return true if this Outcome is a Forward.

Examples
let x: Outcome<i32, &str, usize> = Success(10);
assert_eq!(x.is_forward(), false);

let x: Outcome<i32, &str, usize> = Failure("Hi! I'm an error.");
assert_eq!(x.is_forward(), false);

let x: Outcome<i32, &str, usize> = Forward(25);
assert_eq!(x.is_forward(), true);

Converts from Outcome<S, E, F> to Option<S>.

Returns the Some of the Success if this is a Success, otherwise returns None. self is consumed, and all other values are discarded.

let x: Outcome<i32, &str, usize> = Success(10);
assert_eq!(x.succeeded(), Some(10));

let x: Outcome<i32, &str, usize> = Failure("Hi! I'm an error.");
assert_eq!(x.succeeded(), None);

let x: Outcome<i32, &str, usize> = Forward(25);
assert_eq!(x.succeeded(), None);

Converts from Outcome<S, E, F> to Option<E>.

Returns the Some of the Failure if this is a Failure, otherwise returns None. self is consumed, and all other values are discarded.

let x: Outcome<i32, &str, usize> = Success(10);
assert_eq!(x.failed(), None);

let x: Outcome<i32, &str, usize> = Failure("Hi! I'm an error.");
assert_eq!(x.failed(), Some("Hi! I'm an error."));

let x: Outcome<i32, &str, usize> = Forward(25);
assert_eq!(x.failed(), None);

Converts from Outcome<S, E, F> to Option<F>.

Returns the Some of the Forward if this is a Forward, otherwise returns None. self is consumed, and all other values are discarded.

let x: Outcome<i32, &str, usize> = Success(10);
assert_eq!(x.forwarded(), None);

let x: Outcome<i32, &str, usize> = Failure("Hi! I'm an error.");
assert_eq!(x.forwarded(), None);

let x: Outcome<i32, &str, usize> = Forward(25);
assert_eq!(x.forwarded(), Some(25));

Returns a Success value as Ok() or value in Err. Converts from Outcome<S, E, F> to Result<S, T> for a given T.

Returns Ok with the Success value if this is a Success, otherwise returns an Err with the provided value. self is consumed, and all other values are discarded.

let x: Outcome<i32, &str, usize> = Success(10);
assert_eq!(x.success_or(false), Ok(10));

let x: Outcome<i32, &str, usize> = Failure("Hi! I'm an error.");
assert_eq!(x.success_or(false), Err(false));

let x: Outcome<i32, &str, usize> = Forward(25);
assert_eq!(x.success_or("whoops"), Err("whoops"));

Returns a Success value as Ok() or f() in Err. Converts from Outcome<S, E, F> to Result<S, T> for a given T produced from a supplied function or closure.

Returns Ok with the Success value if this is a Success, otherwise returns an Err with the result of calling f. self is consumed, and all other values are discarded.

let x: Outcome<i32, &str, usize> = Success(10);
assert_eq!(x.success_or_else(|| false), Ok(10));

let x: Outcome<i32, &str, usize> = Failure("Hi! I'm an error.");
assert_eq!(x.success_or_else(|| false), Err(false));

let x: Outcome<i32, &str, usize> = Forward(25);
assert_eq!(x.success_or_else(|| "whoops"), Err("whoops"));

Converts from Outcome<S, E, F> to Outcome<&S, &E, &F>.

let x: Outcome<i32, &str, usize> = Success(10);
assert_eq!(x.as_ref(), Success(&10));

let x: Outcome<i32, &str, usize> = Failure("Hi! I'm an error.");
assert_eq!(x.as_ref(), Failure(&"Hi! I'm an error."));

Converts from Outcome<S, E, F> to Outcome<&mut S, &mut E, &mut F>.

let mut x: Outcome<i32, &str, usize> = Success(10);
if let Success(val) = x.as_mut() {
    *val = 20;
}

assert_eq!(x.unwrap(), 20);

Maps the Success value using f. Maps an Outcome<S, E, F> to an Outcome<T, E, F> by applying the function f to the value of type S in self if self is an Outcome::Success.

let x: Outcome<i32, &str, usize> = Success(10);

let mapped = x.map(|v| if v == 10 { "10" } else { "not 10" });
assert_eq!(mapped, Success("10"));

Maps the Failure value using f. Maps an Outcome<S, E, F> to an Outcome<S, T, F> by applying the function f to the value of type E in self if self is an Outcome::Failure.

let x: Outcome<i32, &str, usize> = Failure("hi");

let mapped = x.map_failure(|v| if v == "hi" { 10 } else { 0 });
assert_eq!(mapped, Failure(10));

Maps the Forward value using f. Maps an Outcome<S, E, F> to an Outcome<S, E, T> by applying the function f to the value of type F in self if self is an Outcome::Forward.

let x: Outcome<i32, &str, usize> = Forward(5);

let mapped = x.map_forward(|v| if v == 5 { "a" } else { "b" });
assert_eq!(mapped, Forward("a"));

Converts from Outcome<S, E, F> to Outcome<T, E, F> using f to map Success(S) to Success(T).

If self is not Success, self is returned.

Examples
let x: Outcome<i32, &str, bool> = Success(10);

let mapped = x.and_then(|v| match v {
   10 => Success("10"),
   1 => Forward(false),
   _ => Failure("30")
});

assert_eq!(mapped, Success("10"));

Converts from Outcome<S, E, F> to Outcome<S, T, F> using f to map Failure(E) to Failure(T).

If self is not Failure, self is returned.

Examples
let x: Outcome<i32, &str, bool> = Failure("hi");

let mapped = x.failure_then(|v| match v {
   "hi" => Failure(10),
   "test" => Forward(false),
   _ => Success(10)
});

assert_eq!(mapped, Failure(10));

Converts from Outcome<S, E, F> to Outcome<S, E, T> using f to map Forward(F) to Forward(T).

If self is not Forward, self is returned.

Examples
let x: Outcome<i32, &str, Option<bool>> = Forward(Some(false));

let mapped = x.forward_then(|v| match v {
   Some(true) => Success(10),
   Some(false) => Forward(20),
   None => Failure("10")
});

assert_eq!(mapped, Forward(20));

Converts Outcome<S, E, F> to Result<S, E> by identity mapping Success(S) and Failure(E) to Result<T, E> and mapping Forward(F) to Result<T, E> using f.

let x: Outcome<i32, &str, usize> = Success(10);
assert_eq!(x.ok_map_forward(|x| Ok(x as i32 + 1)), Ok(10));

let x: Outcome<i32, &str, usize> = Failure("hello");
assert_eq!(x.ok_map_forward(|x| Ok(x as i32 + 1)), Err("hello"));

let x: Outcome<i32, &str, usize> = Forward(0);
assert_eq!(x.ok_map_forward(|x| Ok(x as i32 + 1)), Ok(1));

Converts Outcome<S, E, F> to Result<S, E> by identity mapping Success(S) and Forward(F) to Result<T, F> and mapping Failure(E) to Result<T, F> using f.

let x: Outcome<i32, &str, usize> = Success(10);
assert_eq!(x.ok_map_failure(|s| Ok(123)), Ok(10));

let x: Outcome<i32, &str, usize> = Failure("hello");
assert_eq!(x.ok_map_failure(|s| Ok(123)), Ok(123));

let x: Outcome<i32, &str, usize> = Forward(0);
assert_eq!(x.ok_map_failure(|s| Ok(123)), Err(0));

Pins a future that resolves to self, returning a BoxFuture that resolves to self.

Return the Outcome of response to req from responder.

If the responder returns Ok, an outcome of Success is returned with the response. If the responder returns Err, an outcome of Failure is returned with the status code.

Example
use rocket::{Request, Data, route};

fn str_responder<'r>(req: &'r Request, _: Data<'r>) -> route::Outcome<'r> {
    route::Outcome::from(req, "Hello, world!")
}

Return the Outcome of response to req from responder.

If the responder returns Ok, an outcome of Success is returned with the response. If the responder returns Err, an outcome of Failure is returned with the status code.

Example
use rocket::{Request, Data, route};

fn str_responder<'r>(req: &'r Request, _: Data<'r>) -> route::Outcome<'r> {
    route::Outcome::from(req, "Hello, world!")
}

Return the Outcome of response to req from responder.

If the responder returns Ok, an outcome of Success is returned with the response. If the responder returns Err, an outcome of Forward is returned.

Example
use rocket::{Request, Data, route};

fn str_responder<'r>(req: &'r Request, data: Data<'r>) -> route::Outcome<'r> {
    route::Outcome::from_or_forward(req, data, "Hello, world!")
}

Return an Outcome of Failure with the status code code. This is equivalent to Outcome::Failure(code).

This method exists to be used during manual routing.

Example
use rocket::{Request, Data, route};
use rocket::http::Status;

fn bad_req_route<'r>(_: &'r Request, _: Data<'r>) -> route::Outcome<'r> {
    route::Outcome::failure(Status::BadRequest)
}

Return an Outcome of Forward with the data data. This is equivalent to Outcome::Forward(data).

This method exists to be used during manual routing.

Example
use rocket::{Request, Data, route};

fn always_forward<'r>(_: &'r Request, data: Data<'r>) -> route::Outcome<'r> {
    route::Outcome::forward(data)
}

Trait Implementations

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

Formats the value using the given formatter. Read more

Formats the value using the given formatter. Read more

Feeds this value into the given Hasher. Read more

Feeds a slice of this type into the given Hasher. Read more

This method returns an Ordering between self and other. Read more

Compares and returns the maximum of two values. Read more

Compares and returns the minimum of two values. Read more

Restrict a value to a certain interval. Read more

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.

This method returns an ordering between self and other values if one exists. Read more

This method tests less than (for self and other) and is used by the < operator. Read more

This method tests less than or equal to (for self and other) and is used by the <= operator. Read more

This method tests greater than (for self and other) and is used by the > operator. Read more

This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Compare self to key and return true if they are equal.

Returns the argument unchanged.

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

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

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Converts self into a collection.

Should always be Self

The resulting type after obtaining ownership.

Creates owned data from borrowed data, usually by cloning. Read more

🔬 This is a nightly-only experimental API. (toowned_clone_into)

Uses borrowed data to replace owned data, usually by cloning. Read more

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The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.

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