Trait core::ops::FromResidual [−][src]
pub trait FromResidual<R = Self::Residual> { fn from_residual(residual: R) -> Self; }
Used to specify which residuals can be converted into which Try types.
Every Try type needs to be recreatable from its own associated
Residual type, but can also have additional FromResidual implementations
to support interconversion with other Try types.
Required methods
fn from_residual(residual: R) -> Self[src]
Constructs the type from a compatible Residual type.
This should be implemented consistently with the branch method such
that applying the ? operator will get back an equivalent residual:
FromResidual::from_residual(r).branch() --> ControlFlow::Break(r).
(It may not be an identical residual when interconversion is involved.)
Examples
#![feature(try_trait_v2)] #![feature(control_flow_enum)] use std::ops::{ControlFlow, FromResidual}; assert_eq!(Result::<String, i64>::from_residual(Err(3_u8)), Err(3)); assert_eq!(Option::<String>::from_residual(None), None); assert_eq!( ControlFlow::<_, String>::from_residual(ControlFlow::Break(5)), ControlFlow::Break(5), );Run
Implementors
impl<B, C> FromResidual<<ControlFlow<B, C> as Try>::Residual> for ControlFlow<B, C>[src]
impl<B, C> FromResidual<<ControlFlow<B, C> as Try>::Residual> for ControlFlow<B, C>[src]fn from_residual(residual: ControlFlow<B, Infallible>) -> Self[src]
impl<T> FromResidual<<Option<T> as Try>::Residual> for Option<T>[src]
impl<T> FromResidual<<Option<T> as Try>::Residual> for Option<T>[src]fn from_residual(residual: Option<Infallible>) -> Self[src]
impl<T, E, F: From<E>> FromResidual<Result<Infallible, E>> for Result<T, F>[src]
impl<T, E, F: From<E>> FromResidual<Result<Infallible, E>> for Result<T, F>[src]fn from_residual(residual: Result<Infallible, E>) -> Self[src]
impl<T, E, F: From<E>> FromResidual<Result<Infallible, E>> for Poll<Option<Result<T, F>>>[src]
impl<T, E, F: From<E>> FromResidual<Result<Infallible, E>> for Poll<Option<Result<T, F>>>[src]fn from_residual(x: Result<Infallible, E>) -> Self[src]
impl<T, E, F: From<E>> FromResidual<Result<Infallible, E>> for Poll<Result<T, F>>[src]
impl<T, E, F: From<E>> FromResidual<Result<Infallible, E>> for Poll<Result<T, F>>[src]