use core::unstable::run_in_bare_thread; extern { pub fn rust_dbg_call(cb: *u8, data: libc::uintptr_t) -> libc::uintptr_t; } pub fn main() { unsafe { do run_in_bare_thread() { unsafe { let i = &100; rust_dbg_call(callback, cast::transmute(i)); } } } } extern fn callback(data: libc::uintptr_t) { unsafe { let data: *int = cast::transmute(data); fail_unless!(*data == 100); } }