Auto merge of #120486 - reitermarkus:use-generic-nonzero, r=dtolnay

Use generic `NonZero` internally.

Tracking issue: https://github.com/rust-lang/rust/issues/120257

library/proc_macro/src/bridge/handle.rs

@@ -2,13 +2,13 @@
 
 use std::collections::BTreeMap;
 use std::hash::Hash;
-use std::num::NonZeroU32;
+use std::num::NonZero;
 use std::ops::{Index, IndexMut};
 use std::sync::atomic::{AtomicU32, Ordering};
 
 use super::fxhash::FxHashMap;
 
-pub(super) type Handle = NonZeroU32;
+pub(super) type Handle = NonZero<u32>;
 
 /// A store that associates values of type `T` with numeric handles. A value can
 /// be looked up using its handle.
@@ -20,7 +20,7 @@ pub(super) struct OwnedStore<T: 'static> {
 impl<T> OwnedStore<T> {
     pub(super) fn new(counter: &'static AtomicU32) -> Self {
         // Ensure the handle counter isn't 0, which would panic later,
-        // when `NonZeroU32::new` (aka `Handle::new`) is called in `alloc`.
+        // when `NonZero::new` (aka `Handle::new`) is called in `alloc`.
         assert_ne!(counter.load(Ordering::SeqCst), 0);
 
         OwnedStore { counter, data: BTreeMap::new() }

library/proc_macro/src/bridge/rpc.rs

@@ -2,7 +2,7 @@
 
 use std::any::Any;
 use std::io::Write;
-use std::num::NonZeroU32;
+use std::num::NonZero;
 use std::str;
 
 pub(super) type Writer = super::buffer::Buffer;
@@ -157,13 +157,13 @@ impl<S> DecodeMut<'_, '_, S> for char {
     }
 }
 
-impl<S> Encode<S> for NonZeroU32 {
+impl<S> Encode<S> for NonZero<u32> {
     fn encode(self, w: &mut Writer, s: &mut S) {
         self.get().encode(w, s);
     }
 }
 
-impl<S> DecodeMut<'_, '_, S> for NonZeroU32 {
+impl<S> DecodeMut<'_, '_, S> for NonZero<u32> {
     fn decode(r: &mut Reader<'_>, s: &mut S) -> Self {
         Self::new(u32::decode(r, s)).unwrap()
     }

library/proc_macro/src/bridge/symbol.rs

@@ -10,14 +10,14 @@
 //! proc_macro, this module should probably be removed or simplified.
 
 use std::cell::RefCell;
-use std::num::NonZeroU32;
+use std::num::NonZero;
 use std::str;
 
 use super::*;
 
 /// Handle for a symbol string stored within the Interner.
 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
-pub struct Symbol(NonZeroU32);
+pub struct Symbol(NonZero<u32>);
 
 impl !Send for Symbol {}
 impl !Sync for Symbol {}
@@ -137,7 +137,7 @@ thread_local! {
         names: fxhash::FxHashMap::default(),
         strings: Vec::new(),
         // Start with a base of 1 to make sure that `NonZeroU32` works.
-        sym_base: NonZeroU32::new(1).unwrap(),
+        sym_base: NonZero::new(1).unwrap(),
     });
 }
 
@@ -152,7 +152,7 @@ struct Interner {
     // The offset to apply to symbol names stored in the interner. This is used
     // to ensure that symbol names are not re-used after the interner is
     // cleared.
-    sym_base: NonZeroU32,
+    sym_base: NonZero<u32>,
 }
 
 impl Interner {

library/proc_macro/src/lib.rs

@@ -26,6 +26,7 @@
 #![feature(staged_api)]
 #![feature(allow_internal_unstable)]
 #![feature(decl_macro)]
+#![feature(generic_nonzero)]
 #![feature(maybe_uninit_write_slice)]
 #![feature(negative_impls)]
 #![feature(new_uninit)]