Macro bail 

macro_rules! bail {
    ( $($args:tt)* ) => { ... };
}

Early exit from the current function with an error.

This helper is equivalent to return Err(anyhow!(...)).

See the docs for the anyhow! macro for details on the kinds of errors that can be constructed.

Like anyhow::bail! but for wasmtime::Error.

Example

use wasmtime::{bail, Result};

fn error_on_none(option: Option<u32>) -> Result<u32> {
    match option {
        None => bail!("`error_on_none` got `None`!"),
        Some(x) => Ok(x),
    }
}

let x = error_on_none(Some(42)).unwrap();
assert_eq!(x, 42);

let error = error_on_none(None).unwrap_err();
assert_eq!(
    error.to_string(),
    "`error_on_none` got `None`!",
);