#![feature(intrinsics)] // Directly call intrinsic to avoid debug assertions in libstd extern "rust-intrinsic" { fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int; } fn main() { unsafe { float_to_int_unchecked::<f64, u128>(f64::NEG_INFINITY); //~ ERROR: cannot be represented in target type `u128` } }