#![warn(const_err)] const fn foo(x: u32) -> u32 { x } fn main() { const X: u32 = 0-1; //~^ WARN any use of this value will cause const Y: u32 = foo(0-1); //~^ WARN any use of this value will cause println!("{} {}", X, Y); //~^ ERROR evaluation of constant expression failed //~| ERROR evaluation of constant expression failed }