Struct error_backtrace::nightly::Result

pub struct Result<T, E> { /* private fields */ }

Implementations

impl<T, E> Result<T, E>

pub fn backtrace(&self)

Examples found in repository

examples/example_nightly.rs (line 6)

fn main() -> std::result::Result<(), ()> {
    #[cfg(feature = "nightly")]
    maybe_error().backtrace();

    Ok(())
}

Methods from Deref<Target = Result<T, E>>

pub fn is_ok(&self) -> bool

Returns true if the result is Ok.

Examples

let x: Result<i32, &str> = Ok(-3);
assert_eq!(x.is_ok(), true);

let x: Result<i32, &str> = Err("Some error message");
assert_eq!(x.is_ok(), false);

pub fn is_err(&self) -> bool

Returns true if the result is Err.

Examples

let x: Result<i32, &str> = Ok(-3);
assert_eq!(x.is_err(), false);

let x: Result<i32, &str> = Err("Some error message");
assert_eq!(x.is_err(), true);

pub fn as_ref(&self) -> Result<&T, &E>

Converts from &Result<T, E> to Result<&T, &E>.

Produces a new Result, containing a reference into the original, leaving the original in place.

Examples

let x: Result<u32, &str> = Ok(2);
assert_eq!(x.as_ref(), Ok(&2));

let x: Result<u32, &str> = Err("Error");
assert_eq!(x.as_ref(), Err(&"Error"));

pub fn as_mut(&mut self) -> Result<&mut T, &mut E>

Converts from &mut Result<T, E> to Result<&mut T, &mut E>.

Examples

fn mutate(r: &mut Result<i32, i32>) {
    match r.as_mut() {
        Ok(v) => *v = 42,
        Err(e) => *e = 0,
    }
}

let mut x: Result<i32, i32> = Ok(2);
mutate(&mut x);
assert_eq!(x.unwrap(), 42);

let mut x: Result<i32, i32> = Err(13);
mutate(&mut x);
assert_eq!(x.unwrap_err(), 0);

pub fn as_deref(&self) -> Result<&<T as Deref>::Target, &E>

where T: Deref,

Converts from Result<T, E> (or &Result<T, E>) to Result<&<T as Deref>::Target, &E>.

Coerces the Ok variant of the original Result via Deref and returns the new Result.

Examples

let x: Result<String, u32> = Ok("hello".to_string());
let y: Result<&str, &u32> = Ok("hello");
assert_eq!(x.as_deref(), y);

let x: Result<String, u32> = Err(42);
let y: Result<&str, &u32> = Err(&42);
assert_eq!(x.as_deref(), y);

pub fn as_deref_mut(&mut self) -> Result<&mut <T as Deref>::Target, &mut E>

where T: DerefMut,

Converts from Result<T, E> (or &mut Result<T, E>) to Result<&mut <T as DerefMut>::Target, &mut E>.

Coerces the Ok variant of the original Result via DerefMut and returns the new Result.

Examples

let mut s = "HELLO".to_string();
let mut x: Result<String, u32> = Ok("hello".to_string());
let y: Result<&mut str, &mut u32> = Ok(&mut s);
assert_eq!(x.as_deref_mut().map(|x| { x.make_ascii_uppercase(); x }), y);

let mut i = 42;
let mut x: Result<String, u32> = Err(42);
let y: Result<&mut str, &mut u32> = Err(&mut i);
assert_eq!(x.as_deref_mut().map(|x| { x.make_ascii_uppercase(); x }), y);

pub fn iter(&self) -> Iter<'_, T>

Returns an iterator over the possibly contained value.

The iterator yields one value if the result is Result::Ok, otherwise none.

Examples

let x: Result<u32, &str> = Ok(7);
assert_eq!(x.iter().next(), Some(&7));

let x: Result<u32, &str> = Err("nothing!");
assert_eq!(x.iter().next(), None);

pub fn iter_mut(&mut self) -> IterMut<'_, T>

Returns a mutable iterator over the possibly contained value.

The iterator yields one value if the result is Result::Ok, otherwise none.

Examples

let mut x: Result<u32, &str> = Ok(7);
match x.iter_mut().next() {
    Some(v) => *v = 40,
    None => {},
}
assert_eq!(x, Ok(40));

let mut x: Result<u32, &str> = Err("nothing!");
assert_eq!(x.iter_mut().next(), None);

Trait Implementations

impl<T, E> Deref for Result<T, E>

type Target = Result<T, E>

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<T, E> DerefMut for Result<T, E>

fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.

impl<T, E> From<Result<T, E>> for Result<T, E>

fn from(value: Result<T, E>) -> Self

Converts to this type from the input type.

impl<T, E> FromResidual for Result<T, E>

fn from_residual(residual: <Self as Try>::Residual) -> Self

🔬This is a nightly-only experimental API. (try_trait_v2)

Constructs the type from a compatible Residual type.

impl<T, E> Try for Result<T, E>

type Output = T

🔬This is a nightly-only experimental API. (try_trait_v2)

The type of the value produced by ? when not short-circuiting.

type Residual = (E, Backtrace)

🔬This is a nightly-only experimental API. (try_trait_v2)

The type of the value passed to FromResidual::from_residual as part of ? when short-circuiting.

fn from_output(output: Self::Output) -> Self

🔬This is a nightly-only experimental API. (try_trait_v2)

Constructs the type from its Output type.

fn branch(self) -> ControlFlow<Self::Residual, Self::Output>

🔬This is a nightly-only experimental API. (try_trait_v2)

Used in ? to decide whether the operator should produce a value (because this returned ControlFlow::Continue) or propagate a value back to the caller (because this returned ControlFlow::Break).