// run-pass #![feature(const_eval_select)] #![feature(core_intrinsics)] use std::intrinsics::const_eval_select; const fn yes() -> bool { true } fn no() -> bool { false } // not a sound use case; testing only const fn is_const_eval() -> bool { unsafe { const_eval_select((), yes, no) } } fn main() { const YES: bool = is_const_eval(); let no = is_const_eval(); assert_eq!(true, YES); assert_eq!(false, no); }