fn main() { let is_nightly = version_check::is_feature_flaggable() == Some(true); let is_at_least_1_49 = version_check::is_min_version("1.49.0").unwrap_or(false); let is_at_least_1_51 = version_check::is_min_version("1.51.0").unwrap_or(false); if !is_at_least_1_49 { println!("cargo:warning=slotmap requires rustc => 1.49.0"); } if is_at_least_1_51 || is_nightly { println!("cargo:rustc-cfg=has_min_const_generics"); } if is_nightly { println!("cargo:rustc-cfg=nightly"); } }