fn nightly_rustc() -> bool {
fn op() -> Option<bool> {
use std::{env, process, str};
let rustc = env::var_os("RUSTC")?;
let output = process::Command::new(rustc)
.arg("--version")
.output()
.ok()?;
let version = str::from_utf8(&output.stdout).ok()?;
Some(version.contains("nightly"))
}
if let Some(true) = op() {
true
} else {
false
}
}
fn main() {
if nightly_rustc() {
println!("cargo:rustc-cfg=bitintr_nightly");
}
}