Moved co_alloc_metadata_num_slots_with_preference_global from ::core::alloc to ::alloc.

Author: peter-lyons-kehl

library/alloc/src/boxed.rs

@@ -1686,7 +1686,7 @@ impl<T, const N: usize> TryFrom<Box<[T]>> for Box<[T; N]> {
 impl<T, const N: usize, const COOP_PREFERRED: bool> TryFrom<Vec<T, Global, COOP_PREFERRED>>
     for Box<[T; N]>
 where
-    [(); alloc::co_alloc_metadata_num_slots_with_preference_global(COOP_PREFERRED)]:,
+    [(); crate::co_alloc_metadata_num_slots_with_preference_global(COOP_PREFERRED)]:,
 {
     type Error = Vec<T, Global, COOP_PREFERRED>;
 

library/alloc/src/collections/binary_heap/mod.rs

@@ -1525,15 +1525,15 @@ unsafe impl<T: Ord> TrustedLen for IntoIterSorted<T> {}
 #[derive(Debug)]
 pub struct Drain<'a, T: 'a, const COOP_PREFERRED: bool>
 where
-    [(); alloc::co_alloc_metadata_num_slots_with_preference_global(COOP_PREFERRED)]:,
+    [(); crate::co_alloc_metadata_num_slots_with_preference_global(COOP_PREFERRED)]:,
 {
     iter: vec::Drain<'a, T, Global, COOP_PREFERRED>,
 }
 
 #[stable(feature = "drain", since = "1.6.0")]
 impl<T, const COOP_PREFERRED: bool> Iterator for Drain<'_, T, COOP_PREFERRED>
 where
-    [(); alloc::co_alloc_metadata_num_slots_with_preference_global(COOP_PREFERRED)]:,
+    [(); crate::co_alloc_metadata_num_slots_with_preference_global(COOP_PREFERRED)]:,
 {
     type Item = T;
 

library/alloc/src/lib.rs

@@ -284,4 +284,11 @@ pub(crate) mod test_helpers {
         let seed: [u8; 16] = seed_vec.as_slice().try_into().unwrap();
         rand::SeedableRng::from_seed(seed)
     }
+
+use crate::alloc::Global;
+
+/// See also `core::alloc::co_alloc_metadata_num_slots_with_preference`.
+#[unstable(feature = "global_co_alloc", issue = "none")]
+pub const fn co_alloc_metadata_num_slots_with_preference_global(coop_preferred: bool) -> usize {
+    if Global::IS_CO_ALLOCATOR && coop_preferred { 1 } else { 0 }
 }

library/alloc/src/raw_vec.rs

@@ -69,7 +69,7 @@ pub(crate) struct RawVec<
 
 impl<T, const COOP_PREFERRED: bool> RawVec<T, Global, COOP_PREFERRED>
 where
-    [(); alloc::co_alloc_metadata_num_slots_with_preference_global(COOP_PREFERRED)]:,
+    [(); crate::co_alloc_metadata_num_slots_with_preference_global(COOP_PREFERRED)]:,
 {
     /// HACK(Centril): This exists because stable `const fn` can only call stable `const fn`, so
     /// they cannot call `Self::new()`.

library/alloc/src/rc.rs

@@ -247,7 +247,6 @@ use crate::boxed::Box;
 #[cfg(test)]
 use std::boxed::Box;
 
-use crate::alloc;
 use core::any::Any;
 use core::borrow;
 use core::cell::Cell;
@@ -1990,7 +1989,7 @@ impl<T: ?Sized> From<Box<T>> for Rc<T> {
 #[stable(feature = "shared_from_slice", since = "1.21.0")]
 impl<T, const COOP_PREFERRED: bool> From<Vec<T, Global, COOP_PREFERRED>> for Rc<[T]>
 where
-    [(); alloc::co_alloc_metadata_num_slots_with_preference_global(COOP_PREFERRED)]:,
+    [(); crate::co_alloc_metadata_num_slots_with_preference_global(COOP_PREFERRED)]:,
 {
     /// Allocate a reference-counted slice and move `v`'s items into it.
     ///
@@ -2005,7 +2004,7 @@ where
     #[inline]
     fn from(mut v: Vec<T, Global, COOP_PREFERRED>) -> Rc<[T]>
     where
-        [(); alloc::co_alloc_metadata_num_slots_with_preference_global(COOP_PREFERRED)]:,
+        [(); crate::co_alloc_metadata_num_slots_with_preference_global(COOP_PREFERRED)]:,
     {
         unsafe {
             let rc = Rc::copy_from_slice(&v);

library/alloc/src/str.rs

@@ -136,7 +136,7 @@ where
     T: Copy,
     B: AsRef<[T]> + ?Sized,
     S: Borrow<B>,
-    [(); alloc::co_alloc_metadata_num_slots_with_preference_global(COOP_PREFERRED)]:,
+    [(); crate::co_alloc_metadata_num_slots_with_preference_global(COOP_PREFERRED)]:,
 {
     let sep_len = sep.len();
     let mut iter = slice.iter();