#![forbid(unsafe_code)] #![warn(rust_2018_idioms, single_use_lifetimes)] use autocfg::AutoCfg; // The rustc-cfg strings below are *not* public API. Please let us know by // opening a GitHub issue if your build environment requires some way to enable // these cfgs other than by executing our build script. fn main() { let cfg = match AutoCfg::new() { Ok(cfg) => cfg, Err(e) => { println!( "cargo:warning={}: unable to determine rustc version: {}", env!("CARGO_PKG_NAME"), e ); return; } }; if cfg.probe_rustc_version(1, 36) { println!("cargo:rustc-cfg=stable_1_36"); } }