CoAlloc: library/proc_macro (+related library/alloc): Experimenting with importing DEFAULT_COOP_PREFERRED

Author: peter-lyons-kehl

library/alloc/src/vec/mod.rs

@@ -150,6 +150,7 @@ use self::spec_extend::SpecExtend;
 mod spec_extend;
 
 /// Default `Vec`, `DefVec`, `DecVeque`, `DefDecVeq` "cooperation" (`COOP_PREFERRED`) generic parameter.
+/// NOT for public use. It's exported only so that library/proc_macro (and other internals) can use this. TODO FIXME.
 #[unstable(feature = "global_co_alloc_def", issue = "none")]
 // pub const DEFAULT_COOP_PREFERRED: bool = true;
 #[macro_export]

library/proc_macro/src/bridge/rpc.rs

@@ -5,6 +5,9 @@ use std::char;
 use std::io::Write;
 use std::num::NonZeroU32;
 use std::str;
+//use std::alloc::Global;
+use alloc::DEFAULT_COOP_PREFERRED;
+use alloc::alloc::Global;
 
 pub(super) type Writer = super::buffer::Buffer;
 
@@ -225,7 +228,7 @@ impl<S> DecodeMut<'_, '_, S> for String {
     }
 }
 
-impl<S, T: Encode<S>> Encode<S> for Vec<T, Global, DEFAULT_COOP_PREFERRED> {
+impl<S, T: Encode<S>> Encode<S> for Vec<T, Global, DEFAULT_COOP_PREFERRED!()> {
     fn encode(self, w: &mut Writer, s: &mut S) {
         self.len().encode(w, s);
         for x in self {

library/proc_macro/src/lib.rs

@@ -33,6 +33,7 @@
 #![feature(min_specialization)]
 #![feature(strict_provenance)]
 #![recursion_limit = "256"]
+#![feature(global_co_alloc_def)]
 
 #[unstable(feature = "proc_macro_internals", issue = "27812")]
 #[doc(hidden)]