Move alloc::prelude::* to alloc::prelude::v1, make alloc a subset of std

src/liballoc/prelude/mod.rs

@@ -0,0 +1,16 @@
+//! The alloc Prelude
+//!
+//! The purpose of this module is to alleviate imports of commonly-used
+//! items of the `alloc` crate by adding a glob import to the top of modules:
+//!
+//! ```
+//! # #![allow(unused_imports)]
+//! # #![feature(alloc)]
+//! #![feature(alloc_prelude)]
+//! extern crate alloc;
+//! use alloc::prelude::v1::*;
+//! ```
+
+#![unstable(feature = "alloc_prelude", issue = "58935")]
+
+pub mod v1;

src/liballoc/prelude/v1.rs

@@ -0,0 +1,11 @@
+//! The first version of the prelude of `alloc` crate.
+//!
+//! See the [module-level documentation](../index.html) for more.
+
+#![unstable(feature = "alloc_prelude", issue = "58935")]
+
+#[unstable(feature = "alloc_prelude", issue = "58935")] pub use crate::borrow::ToOwned;
+#[unstable(feature = "alloc_prelude", issue = "58935")] pub use crate::boxed::Box;
+#[unstable(feature = "alloc_prelude", issue = "58935")] pub use crate::slice::SliceConcatExt;
+#[unstable(feature = "alloc_prelude", issue = "58935")] pub use crate::string::{String, ToString};
+#[unstable(feature = "alloc_prelude", issue = "58935")] pub use crate::vec::Vec;