bail

Return early with an error.

This macro is equivalent to return Err(anyhow!($args...)).

The surrounding function's or closure's return value is required to be Result<_, [anyhow::Error][crate::Error]>.

Example

if !has_permission(user, resource) {
    bail!("permission denied for accessing {}", resource);
}

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#[derive(Error, Debug)]
enum ScienceError {
    #[error("recursion limit exceeded")]
    RecursionLimitExceeded,
    ...
}

if depth > MAX_DEPTH {
    bail!(ScienceError::RecursionLimitExceeded);
}