Lightweight error-handling. Provides `Option<T>::oops(self, &str) -> Result<T>`. ```rust use std::io::Result; use oops::Opps; fn third_element(slice: &[usize]) -> Result<&usize> { slice.iter().nth(3).oops("No third element") } fn main() -> Result<()> { third_element(&[1, 2, 3]) } ```