Remove usage of unstable core::num::Zero, which was removed upstream.

rust-lang/rust#41437

Author: SimonSapin

serde/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde"
-version = "1.0.0" # remember to update html_root_url
+version = "1.0.1" # remember to update html_root_url
 authors = ["Erick Tryzelaar <[email protected]>", "David Tolnay <[email protected]>"]
 license = "MIT/Apache-2.0"
 description = "A generic serialization/deserialization framework"

serde/src/de/impls.rs

@@ -1471,22 +1471,24 @@ where
 ////////////////////////////////////////////////////////////////////////////////
 
 #[cfg(feature = "unstable")]
-#[allow(deprecated)] // num::Zero is deprecated but there is no replacement
 impl<'de, T> Deserialize<'de> for NonZero<T>
 where
-    T: Deserialize<'de> + PartialEq + Zeroable + Zero,
+    T: Deserialize<'de> + Zeroable,
 {
     fn deserialize<D>(deserializer: D) -> Result<NonZero<T>, D::Error>
     where
         D: Deserializer<'de>,
     {
         let value = try!(Deserialize::deserialize(deserializer));
-        if value == Zero::zero() {
-            return Err(Error::custom("expected a non-zero value"));
+        unsafe {
+            let ptr = &value as *const T as *const u8;
+            if slice::from_raw_parts(ptr, mem::size_of::<T>()).iter().all(|&b| b == 0) {
+                return Err(Error::custom("expected a non-zero value"));
+            }
+            // Waiting for a safe way to construct NonZero<T>:
+            // https://github.com/rust-lang/rust/issues/27730#issuecomment-269726075
+            Ok(NonZero::new(value))
         }
-        // Waiting for a safe way to construct NonZero<T>:
-        // https://github.com/rust-lang/rust/issues/27730#issuecomment-269726075
-        unsafe { Ok(NonZero::new(value)) }
     }
 }
 

serde/src/lib.rs

@@ -79,7 +79,7 @@
 ////////////////////////////////////////////////////////////////////////////////
 
 // Serde types in rustdoc of other crates get linked to here.
-#![doc(html_root_url = "https://docs.rs/serde/1.0.0")]
+#![doc(html_root_url = "https://docs.rs/serde/1.0.1")]
 
 // Support using Serde without the standard library!
 #![cfg_attr(not(feature = "std"), no_std)]
@@ -88,7 +88,7 @@
 // discussion of these features please refer to this issue:
 //
 //    https://github.com/serde-rs/serde/issues/812
-#![cfg_attr(feature = "unstable", feature(nonzero, specialization, zero_one))]
+#![cfg_attr(feature = "unstable", feature(nonzero, specialization))]
 #![cfg_attr(all(feature = "std", feature = "unstable"), feature(into_boxed_c_str))]
 #![cfg_attr(feature = "alloc", feature(alloc))]
 #![cfg_attr(feature = "collections", feature(collections))]
@@ -124,7 +124,7 @@ mod lib {
         pub use core::*;
     }
 
-    pub use self::core::{cmp, iter, mem, ops, str};
+    pub use self::core::{cmp, iter, mem, ops, slice, str};
     pub use self::core::{i8, i16, i32, i64, isize};
     pub use self::core::{u8, u16, u32, u64, usize};
     pub use self::core::{f32, f64};
@@ -193,9 +193,6 @@ mod lib {
 
     #[cfg(feature = "unstable")]
     pub use core::nonzero::{NonZero, Zeroable};
-    #[cfg(feature = "unstable")]
-    #[allow(deprecated)] // required for impl Deserialize for NonZero<T>
-    pub use core::num::Zero;
 }
 
 ////////////////////////////////////////////////////////////////////////////////