| Panics the current thread. |
| |
| This allows a program to terminate immediately and provide feedback |
| to the caller of the program. `panic!` should be used when a program reaches |
| an unrecoverable state. |
| |
| This macro is the perfect way to assert conditions in example code and in |
| tests. `panic!` is closely tied with the `unwrap` method of both |
| [`Option`][ounwrap] and [`Result`][runwrap] enums. Both implementations call |
| `panic!` when they are set to [`None`] or [`Err`] variants. |
| |
| This macro is used to inject panic into a Rust thread, causing the thread to |
| panic entirely. Each thread's panic can be reaped as the [`Box`]`<`[`Any`]`>` type, |
| and the single-argument form of the `panic!` macro will be the value which |
| is transmitted. |
| |
| [`Result`] enum is often a better solution for recovering from errors than |
| using the `panic!` macro. This macro should be used to avoid proceeding using |
| incorrect values, such as from external sources. Detailed information about |
| error handling is found in the [book]. |
| |
| The multi-argument form of this macro panics with a string and has the |
| [`format!`] syntax for building a string. |
| |
| See also the macro [`compile_error!`], for raising errors during compilation. |
| |
| [ounwrap]: Option::unwrap |
| [runwrap]: Result::unwrap |
| [`Box`]: ../std/boxed/struct.Box.html |
| [`Any`]: crate::any::Any |
| [`format!`]: ../std/macro.format.html |
| [book]: ../book/ch09-00-error-handling.html |
| |
| # Current implementation |
| |
| If the main thread panics it will terminate all your threads and end your |
| program with code `101`. |
| |
| # Examples |
| |
| ```should_panic |
| # #![allow(unreachable_code)] |
| panic!(); |
| panic!("this is a terrible mistake!"); |
| panic!(4); // panic with the value of 4 to be collected elsewhere |
| panic!("this is a {} {message}", "fancy", message = "message"); |
| ``` |
