1use thiserror::Error; 2 3#[derive(Error, Debug)] 4pub enum IndexError { 5 /// (expected x, expected y, found x, found y) 6 #[error("invalid index (expected x<{0}, y<{1} but got x={2}, y={3}) ")] 7 USizeMatrix(usize, usize, usize, usize) 8}