Macro snafu::ensure [−][src]
Ensure a condition is true. If it is not, return from the function with an error.
use snafu::{ensure, Snafu}; #[derive(Debug, Snafu)] enum Error { InvalidUser { user_id: i32 }, } fn example(user_id: i32) -> Result<(), Error> { ensure!(user_id > 0, InvalidUser { user_id }); // After this point, we know that `user_id` is positive. let user_id = user_id as u32; Ok(()) }