Using anyhow::ensure!()
(Jin Qing’s Column, Dec., 2023)
From: https://yukinarit.hashnode.dev/10-tips-of-rust-anyhow
use anyhow::{Result, bail};
fn validate(s: &str) -> Result<()> {
if s.len() >= 10 {
bail!("Length of string \"{}\" must be less than 10", s);
}
...
}
can be rewritten as:
use anyhow::{Result, ensure};
fn validate(s: &str) -> Result<()> {
ensure!(s.len() >= 10, "Length of string \"{}\" must be less than 10", s);
...
}
The example from the doc:
#[derive(Error, Debug)]
enum ScienceError {
#[error("recursion limit exceeded")]
RecursionLimitExceeded,
...
}
ensure!(depth <= MAX_DEPTH, ScienceError::RecursionLimitExceeded);
The ensure!() returns Err(anyhow!(…)) if the condition is not met.