#[lang = "try"]pub trait Try {
type Ok;
type Error;
#[lang = "into_result"] fn into_result(self) -> Result<Self::Ok, Self::Error>;
#[lang = "from_error"] fn from_error(v: Self::Error) -> Self;
#[lang = "from_ok"] fn from_ok(v: Self::Ok) -> Self;
}
A trait for customizing the behavior of the ? operator.
A type implementing Try is one that has a canonical way to view it in terms of a success/failure dichotomy. This trait allows both extracting those success or failure values from an existing instance and creating a new instance from a success or failure value.
type OkThe type of this value when viewed as successful.
type ErrorThe type of this value when viewed as failed.
#[lang = "into_result"]fn into_result(self) -> Result<Self::Ok, Self::Error>Applies the "?" operator. A return of Ok(t) means that the execution should continue normally, and the result of ? is the value t. A return of Err(e) means that execution should branch to the innermost enclosing catch, or return from the function.
If an Err(e) result is returned, the value e will be "wrapped" in the return type of the enclosing scope (which must itself implement Try). Specifically, the value X::from_error(From::from(e)) is returned, where X is the return type of the enclosing function.
#[lang = "from_error"]fn from_error(v: Self::Error) -> SelfWrap an error value to construct the composite result. For example, Result::Err(x) and Result::from_error(x) are equivalent.
#[lang = "from_ok"]fn from_ok(v: Self::Ok) -> SelfWrap an OK value to construct the composite result. For example, Result::Ok(x) and Result::from_ok(x) are equivalent.
impl<T> Try for Option<T>[src]
type Ok = Ttype Error = NoneErrorfn into_result(self) -> Result<T, NoneError>[src]
fn from_ok(v: T) -> Option<T>[src]
fn from_error(NoneError) -> Option<T>[src]
impl<T, E> Try for Result<T, E>[src]
type Ok = Ttype Error = Efn into_result(self) -> Result<T, E>[src]
fn from_ok(v: T) -> Result<T, E>[src]
fn from_error(v: E) -> Result<T, E>[src]
impl<T, E> Try for Poll<Option<Result<T, E>>>[src]
type Ok = Poll<Option<T>>type Error = Efn into_result(
    self
) -> Result<<Poll<Option<Result<T, E>>> as Try>::Ok, <Poll<Option<Result<T, E>>> as Try>::Error>[src]
fn from_error(
    e: <Poll<Option<Result<T, E>>> as Try>::Error
) -> Poll<Option<Result<T, E>>>[src]
fn from_ok(
    x: <Poll<Option<Result<T, E>>> as Try>::Ok
) -> Poll<Option<Result<T, E>>>[src]
impl<T, E> Try for Poll<Result<T, E>>[src]
type Ok = Poll<T>type Error = Efn into_result(
    self
) -> Result<<Poll<Result<T, E>> as Try>::Ok, <Poll<Result<T, E>> as Try>::Error>[src]
fn from_error(e: <Poll<Result<T, E>> as Try>::Error) -> Poll<Result<T, E>>[src]
fn from_ok(x: <Poll<Result<T, E>> as Try>::Ok) -> Poll<Result<T, E>>[src]
© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/ops/trait.Try.html