Macro bail 

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

Early exit from the current function with an error.

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

See the docs for the format_err! 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`!",
);