Error code E0755
The ffi_pure
attribute was used on a non-foreign function.
Erroneous code example:
#![feature(ffi_pure)] #[ffi_pure] // error! pub fn foo() {} fn main() {}
The ffi_pure
attribute can only be used on foreign functions which do not have
side effects or infinite loops:
#![feature(ffi_pure)] extern "C" { #[ffi_pure] // ok! pub fn strlen(s: *const i8) -> isize; } fn main() {}
You can find more information about it in the unstable Rust Book.