extern crate rustc_version;
use rustc_version::{version_meta, Channel};
fn main() {
                match version_meta().unwrap().channel {
        Channel::Stable => {
            println!("cargo:rustc-cfg=RUSTC_WITHOUT_SPECIALIZATION");
        }
        Channel::Beta => {
            println!("cargo:rustc-cfg=RUSTC_WITHOUT_SPECIALIZATION");
        }
        Channel::Nightly => {
            println!("cargo:rustc-cfg=RUSTC_WITH_SPECIALIZATION");
        }
        Channel::Dev => {
            println!("cargo:rustc-cfg=RUSTC_WITH_SPECIALIZATION");
                                                            println!("cargo:rustc-cfg=RUSTC_NEEDS_PROC_MACRO_HYGIENE");
        }
    }
}