Auto merge of #51569 - SimonSapin:liballoc, r=sfackler

Make the public API of the alloc crate a subset of std

This only affects **unstable** APIs.

I plan to submit an RFC proposing to stabilize the crate. The reason it isn’t stable yet (https://github.com/rust-lang/rust/issues/27783) is in case we end up merging the standard library crates into one. However the `core` crate is already stable, so if that happens we’ll need to keep it working somehow (likely by making replacing its contents by `pub use` items). We can do the same for `alloc`. This PR will hopefully make this easier, but even if that doesn’t happen consistency with `std` seems good.

4 files changed, 9 insertions, 8 deletions

diff --git a/src/libstd/collections/hash/map.rs b/src/libstd/collections/hash/map.rs
index ee8c1dc81ad..91912e5f241 100644
--- a/src/libstd/collections/hash/map.rs
+++ b/src/libstd/collections/hash/map.rs
@@ -11,7 +11,7 @@
 use self::Entry::*;
 use self::VacantEntryState::*;
 
-use alloc::CollectionAllocErr;
+use collections::CollectionAllocErr;
 use cell::Cell;
 use borrow::Borrow;
 use cmp::max;
diff --git a/src/libstd/collections/hash/table.rs b/src/libstd/collections/hash/table.rs
index d14b754ddb6..2b319186a8d 100644
--- a/src/libstd/collections/hash/table.rs
+++ b/src/libstd/collections/hash/table.rs
@@ -8,7 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use alloc::{Global, Alloc, Layout, LayoutErr, CollectionAllocErr, handle_alloc_error};
+use alloc::{Global, Alloc, Layout, LayoutErr, handle_alloc_error};
+use collections::CollectionAllocErr;
 use hash::{BuildHasher, Hash, Hasher};
 use marker;
 use mem::{size_of, needs_drop};
diff --git a/src/libstd/collections/mod.rs b/src/libstd/collections/mod.rs
index 42113414183..8d2c82bc0aa 100644
--- a/src/libstd/collections/mod.rs
+++ b/src/libstd/collections/mod.rs
@@ -424,13 +424,13 @@
 #[doc(hidden)]
 pub use ops::Bound;
 #[stable(feature = "rust1", since = "1.0.0")]
-pub use alloc_crate::{BinaryHeap, BTreeMap, BTreeSet};
+pub use alloc_crate::collections::{BinaryHeap, BTreeMap, BTreeSet};
 #[stable(feature = "rust1", since = "1.0.0")]
-pub use alloc_crate::{LinkedList, VecDeque};
+pub use alloc_crate::collections::{LinkedList, VecDeque};
 #[stable(feature = "rust1", since = "1.0.0")]
-pub use alloc_crate::{binary_heap, btree_map, btree_set};
+pub use alloc_crate::collections::{binary_heap, btree_map, btree_set};
 #[stable(feature = "rust1", since = "1.0.0")]
-pub use alloc_crate::{linked_list, vec_deque};
+pub use alloc_crate::collections::{linked_list, vec_deque};
 
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use self::hash_map::HashMap;
@@ -438,7 +438,7 @@ pub use self::hash_map::HashMap;
 pub use self::hash_set::HashSet;
 
 #[unstable(feature = "try_reserve", reason = "new API", issue="48043")]
-pub use alloc::CollectionAllocErr;
+pub use alloc_crate::collections::CollectionAllocErr;
 
 mod hash;
 
diff --git a/src/libstd/sync/mod.rs b/src/libstd/sync/mod.rs
index 642b284c6c7..e12ef8d9eda 100644
--- a/src/libstd/sync/mod.rs
+++ b/src/libstd/sync/mod.rs
@@ -18,7 +18,7 @@
 #![stable(feature = "rust1", since = "1.0.0")]
 
 #[stable(feature = "rust1", since = "1.0.0")]
-pub use alloc_crate::arc::{Arc, Weak};
+pub use alloc_crate::sync::{Arc, Weak};
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use core::sync::atomic;