# [−][src]Module core::panicking

🔬 This is a nightly-only experimental API. (`core_panic`)

internal details of the implementation of the `panic!` and related macros

Panic support for libcore

The core library cannot define panicking, but it does declare panicking. This means that the functions inside of libcore are allowed to panic, but to be useful an upstream crate must define panicking for libcore to use. The current interface for panicking is:

    fn panic_impl(pi: &core::panic::PanicInfo<'_>) -> !

Run

This definition allows for panicking with any general message, but it does not allow for failing with a `Box<Any>` value. (`PanicInfo` just contains a `&(dyn Any + Send)`, for which we fill in a dummy value in `PanicInfo::internal_constructor`.) The reason for this is that libcore is not allowed to allocate.

This module contains a few other panicking functions, but these are just the necessary lang items for the compiler. All panics are funneled through this one function. The actual symbol is declared through the `#[panic_handler]` attribute.

## Functions

panic | Experimental The underlying implementation of libcore's `panic!` macro when no formatting is used.
panic_fmt | Experimental The underlying implementation of libcore's `panic!` macro when formatting is used.