use wherr::wherr; #[wherr] fn concat_files(path1: &str, path2: &str) -> Result> { let mut content1 = std::fs::read_to_string(path1)?; let content2 = std::fs::read_to_string(path2)?; content1.push_str(&content2); Ok(content1) } fn main() { let content = concat_files("file1.txt", "file2.txt").expect("Failed to concatenate the files"); println!("Concatenated content:\n{content}"); }