🎁 add nightly detection build

Cargo.toml

@@ -10,6 +10,13 @@ description = "Generator Library in Rust"
 readme = "README.md"
 keywords = ["generator", "coroutine", "green", "thread", "fiber"]
 categories = ["data-structures", "algorithms"]
+build = "build.rs"
+
+[dependencies]
+log = "0.3"
+
+[build-dependencies]
+rustc_version = "0.2"
 
 [profile.release]
 opt-level=3

build.rs

@@ -0,0 +1,11 @@
+extern crate rustc_version;
+use rustc_version::{version_meta, Channel};
+
+fn main() {
+    // Set cfg flags depending on release channel
+    if let Channel::Nightly = version_meta().unwrap().channel {
+        return println!("cargo:rustc-cfg=nightly");
+    }
+
+    panic!("stable build is not supported now!");
+}

src/lib.rs

@@ -3,19 +3,19 @@
 //! Rust generator library
 //!
 
-#![feature(asm)]
-#![feature(alloc)]
-#![feature(fnbox)]
-#![feature(rustc_private)]
-#![feature(naked_functions)]
-#![feature(core_intrinsics)]
-#![feature(repr_simd)]
+#![cfg_attr(nightly, feature(asm))]
+#![cfg_attr(nightly, feature(alloc))]
+#![cfg_attr(nightly, feature(fnbox))]
+#![cfg_attr(nightly, feature(naked_functions))]
+#![cfg_attr(nightly, feature(core_intrinsics))]
+#![cfg_attr(nightly, feature(repr_simd))]
 
 #![cfg_attr(test, deny(warnings))]
 #![deny(missing_docs)]
 
 #[macro_use]
 extern crate log;
+#[cfg(nightly)]
 extern crate alloc;
 
 mod rt;