[−][src]Trait wasm_bindgen::UnwrapThrowExt
An extension trait for Option<T>
and Result<T, E>
for unwraping the T
value, or throwing a JS error if it is not available.
These methods should have a smaller code size footprint than the normal
Option::unwrap
and Option::expect
methods, but they are specific to
working with wasm and JS.
On non-wasm32 targets, defaults to the normal unwrap/expect calls.
Example
use wasm_bindgen::prelude::*; // If the value is `Option::Some` or `Result::Ok`, then we just get the // contained `T` value. let x = Some(42); assert_eq!(x.unwrap_throw(), 42); let y: Option<i32> = None; // This call would throw an error to JS! // // y.unwrap_throw() // // And this call would throw an error to JS with a custom error message! // // y.expect_throw("woopsie daisy!")
Required methods
fn expect_throw(self, message: &str) -> T
Unwrap this container's T
value, or throw an error to JS with the
given message if the T
value is unavailable (e.g. an Option<T>
is
None
).
Provided methods
fn unwrap_throw(self) -> T
Unwrap this Option
or Result
, but instead of panicking on failure,
throw an exception to JavaScript.
Implementations on Foreign Types
impl<T> UnwrapThrowExt<T> for Option<T>
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fn expect_throw(self, message: &str) -> T
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impl<T, E> UnwrapThrowExt<T> for Result<T, E> where
E: Debug,
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E: Debug,