Macro custom_print::define_panic_hook
source · macro_rules! define_panic_hook { ( $(#[$extern_meta:meta])* $vis:vis fn $name:ident(...), $($args:tt)* ) => { ... }; ( $($args:tt)* ) => { ... }; }
Expand description
Defines panic_hook
function that can be used as panic hook that uses the specified writer.
The first argument specify function name in the format fn FUNC_NAME(...)
and can be omitted to use the default name panic_hook
.
Examples
use once_cell::sync::Lazy;
use std::sync::Mutex;
static MESSAGE: Lazy<Mutex<String>> = Lazy::new(Mutex::default);
fn main() {
use std::panic::{catch_unwind, take_hook};
fn write(value: &str) {
let mut chunks = MESSAGE.lock().unwrap();
*chunks += value;
}
custom_print::define_panic_hook!(concat, write);
std::panic::set_hook(Box::new(panic_hook));
let result = catch_unwind(|| assert_eq!("foo", "bar"));
let _ = take_hook();
assert!(result.is_err());
let message = MESSAGE.lock().unwrap();
assert!(message.contains("panicked"));
assert!(message.contains("assertion failed"));
assert!(message.contains("\"foo\""));
assert!(message.contains("\"bar\""));
}