no_std only when std feature is not enabled

cramertj · cramertj · commit 7fd5a41a7768 · 2018-10-18T19:13:58.000-07:00
diff --git a/futures-channel/src/lib.rs b/futures-channel/src/lib.rs
@@ -5,7 +5,7 @@
 
 #![feature(pin, arbitrary_self_types, futures_api)]
 
-#![no_std]
+#![cfg_attr(not(feature = "std"), no_std)]
 
 #![warn(missing_docs, missing_debug_implementations)]
 #![deny(bare_trait_objects)]
diff --git a/futures-core/src/lib.rs b/futures-core/src/lib.rs
@@ -2,7 +2,7 @@
 
 #![feature(pin, arbitrary_self_types, futures_api)]
 
-#![no_std]
+#![cfg_attr(not(feature = "std"), no_std)]
 
 #![warn(missing_docs, missing_debug_implementations)]
 #![deny(bare_trait_objects)]
diff --git a/futures-io/src/lib.rs b/futures-io/src/lib.rs
@@ -4,7 +4,7 @@
 //! asynchronous analogs to `std::io::{Read, Write}`. The primary difference is
 //! that these traits integrate with the asynchronous task system.
 
-#![no_std]
+#![cfg_attr(not(feature = "std"), no_std)]
 
 #![warn(missing_docs, missing_debug_implementations)]
 #![deny(bare_trait_objects)]
diff --git a/futures-sink/src/lib.rs b/futures-sink/src/lib.rs
@@ -3,7 +3,7 @@
 //! This crate contains the `Sink` trait which allows values to be sent
 //! asynchronously.
 
-#![no_std]
+#![cfg_attr(not(feature = "std"), no_std)]
 #![warn(missing_docs, missing_debug_implementations)]
 #![doc(html_root_url = "https://rust-lang-nursery.github.io/futures-api-docs/0.3.0-alpha.8/futures_sink")]
 
diff --git a/futures/src/lib.rs b/futures/src/lib.rs
@@ -23,7 +23,7 @@
 
 #![feature(pin, arbitrary_self_types, futures_api)]
 
-#![no_std]
+#![cfg_attr(not(feature = "std"), no_std)]
 
 #![warn(missing_docs, missing_debug_implementations)]
 #![deny(bare_trait_objects)]
