vendor/autocfg-1.1.0/examples/versions.rs

extern crate autocfg;

fn main() {
    // Normally, cargo will set `OUT_DIR` for build scripts.
    let ac = autocfg::AutoCfg::with_dir("target").unwrap();
    for i in 0..100 {
        ac.emit_rustc_version(1, i);
    }
}