1 extern crate autocfg; 2 3 use std::env; 4 main()5fn main() { 6 // If the "i128" feature is explicity requested, don't bother probing for it. 7 // It will still cause a build error if that was set improperly. 8 if env::var_os("CARGO_FEATURE_I128").is_some() || autocfg::new().probe_type("i128") { 9 autocfg::emit("has_i128"); 10 } 11 12 autocfg::rerun_path("build.rs"); 13 } 14