Delete support for compilers without NonZero integer types

serde/Cargo.toml

@@ -11,7 +11,7 @@ keywords = ["serde", "serialization", "no_std"]
 license = "MIT OR Apache-2.0"
 readme = "crates-io.md"
 repository = "https://github.com/serde-rs/serde"
-rust-version = "1.27"
+rust-version = "1.28"
 
 [dependencies]
 serde_derive = { version = "=1.0.179", optional = true, path = "../serde_derive" }

serde/build.rs

@@ -16,12 +16,6 @@ fn main() {
     let target = env::var("TARGET").unwrap();
     let emscripten = target == "asmjs-unknown-emscripten" || target == "wasm32-unknown-emscripten";
 
-    // Non-zero integers stabilized in Rust 1.28:
-    // https://blog.rust-lang.org/2018/08/02/Rust-1.28.html#library-stabilizations
-    if minor < 28 {
-        println!("cargo:rustc-cfg=no_num_nonzero");
-    }
-
     // TryFrom, Atomic types, non-zero signed integers, and SystemTime::checked_add
     // stabilized in Rust 1.34:
     // https://blog.rust-lang.org/2019/04/11/Rust-1.34.0.html#tryfrom-and-tryinto

serde/src/de/impls.rs

@@ -82,7 +82,7 @@ macro_rules! impl_deserialize_num {
     ($primitive:ident, $nonzero:ident $(cfg($($cfg:tt)*))*, $deserialize:ident $($method:ident!($($val:ident : $visit:ident)*);)*) => {
         impl_deserialize_num!($primitive, $deserialize $($method!($($val : $visit)*);)*);
 
-        #[cfg(all(not(no_num_nonzero), $($($cfg)*)*))]
+        $(#[cfg($($cfg)*)])*
         impl<'de> Deserialize<'de> for num::$nonzero {
             fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
             where

serde/src/ser/impls.rs

@@ -536,7 +536,6 @@ where
 macro_rules! nonzero_integers {
     ($($T:ident,)+) => {
         $(
-            #[cfg(not(no_num_nonzero))]
             impl Serialize for num::$T {
                 fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
                 where