Lib.rs

程序

Program 模拟 C 的 perror.

use program::perror;
use std::io::{self};

fn print_msg(_: &str) -> io::Result<()> {
    Err(io::Error::new(
        io::ErrorKind::Other,
        "something went wrong!",
    ))
}

fn main() {
    if let Err(e) = print_msg("Hello, world!") {
        perror(e);
    }
}

$ cargo run
   Compiling example v0.1.0 (/root/example)
    Finished dev [unoptimized + debuginfo] target(s) in 0.34s
     Running `target/debug/example`
example: something went wrong!

lib.rs:

程序提供了一个单独的 divergent 函数 (perror) 来模拟 C 的 perror