| #### Note: this error code is no longer emitted by the compiler. | |
| An undefined atomic operation function was declared. | |
| Erroneous code example: | |
| ```ignore (no longer emitted) | |
| #![feature(intrinsics)] | |
| #![allow(internal_features)] | |
| #[rustc_intrinsic] | |
| unsafe fn atomic_foo(); // error: unrecognized atomic operation | |
| // function | |
| ``` | |
| Please check you didn't make a mistake in the function's name. All intrinsic | |
| functions are defined in `library/core/src/intrinsics` in the Rust source code. |