Error code E0093

An unknown intrinsic function was declared.

Erroneous code example:

#![feature(intrinsics)] #![allow(internal_features)] extern "rust-intrinsic" { fn foo(); // error: unrecognized intrinsic function: `foo` } fn main() { unsafe { foo(); } }

Please check you didn't make a mistake in the function's name. All intrinsic functions are defined in compiler/rustc_codegen_llvm/src/intrinsic.rs and in library/core/src/intrinsics.rs in the Rust source code. Example:

#![feature(intrinsics)] #![allow(internal_features)] extern "rust-intrinsic" { fn atomic_fence_seqcst(); // ok! } fn main() { unsafe { atomic_fence_seqcst(); } }