Attribute Macro subplotlib::prelude::throws

#[throws]

Indicate what type a function throws

This attribute macro comes from the fehler crate and is used to indicate that a function “throws” a particular kind of error.

#[throws(io::Error)]
fn create_thingy() {
    // something which might cause an io::Error
}

It transforms a function such that the above function would be compiled effectively as:

fn create_thingy() -> Result<(), io::Error> {
    // something which might cause an io::Error
    Ok(())
}

Return statements and the final expression of the function automatically get wrappered with Ok. You can use the throw macro inside such a function to automatically return an error.