#![allow(unused_variables)] use std::mem; pub fn safe(x: &i32, y: &mut i32) {} //~ ERROR barrier fn main() { let mut x = 0; let xref = &mut x; let xraw: *mut i32 = unsafe { mem::transmute_copy(&xref) }; let xshr = &*xref; // transmute fn ptr around so that we can avoid retagging let safe_raw: fn(x: *const i32, y: *mut i32) = unsafe { mem::transmute::(safe) }; safe_raw(xshr, xraw); }