Error code E0724

Note: this error code is no longer emitted by the compiler.

#[ffi_returns_twice] was used on something other than a foreign function declaration.

Erroneous code example:

#![allow(unused)] #![feature(ffi_returns_twice)] #![crate_type = "lib"] fn main() { #[ffi_returns_twice] // error! pub fn foo() {} }

#[ffi_returns_twice] can only be used on foreign function declarations. For example, we might correct the previous example by declaring the function inside of an extern block.

#![allow(unused)] #![feature(ffi_returns_twice)] fn main() { extern "C" { #[ffi_returns_twice] // ok! pub fn foo(); } }