Check availability of Saturating

Author: cuviper

.github/workflows/ci.yaml

@@ -11,6 +11,7 @@ jobs:
         rust: [
           1.60.0, # MSRV
           1.62.0, # has_total_cmp
+          1.74.0, # has_num_saturating
           stable,
           beta,
           nightly,

Cargo.toml

@@ -31,4 +31,4 @@ std = []
 i128 = []
 
 [build-dependencies]
-autocfg = "1"
+autocfg = "1.2"

build.rs

@@ -1,7 +1,9 @@
 fn main() {
-    let ac = autocfg::new();
+    let mut ac = autocfg::new();
+    ac.set_no_std(true);
 
     ac.emit_expression_cfg("1f64.total_cmp(&2f64)", "has_total_cmp"); // 1.62
+    ac.emit_path_cfg("core::num::Saturating", "has_num_saturating"); // 1.74
 
     autocfg::rerun_path("build.rs");
 }

ci/rustup.sh

@@ -5,6 +5,6 @@
 set -ex
 
 ci=$(dirname $0)
-for version in 1.60.0 1.62.0 stable beta nightly; do
+for version in 1.60.0 1.62.0 1.74.0 stable beta nightly; do
     rustup run "$version" "$ci/test_full.sh"
 done

src/identities.rs

@@ -1,6 +1,9 @@
-use core::num::{Saturating, Wrapping};
+use core::num::Wrapping;
 use core::ops::{Add, Mul};
 
+#[cfg(has_num_saturating)]
+use core::num::Saturating;
+
 /// Defines an additive identity element for `Self`.
 ///
 /// # Laws
@@ -95,6 +98,7 @@ where
     const ZERO: Self = Wrapping(T::ZERO);
 }
 
+#[cfg(has_num_saturating)]
 impl<T: Zero> Zero for Saturating<T>
 where
     Saturating<T>: Add<Output = Saturating<T>>,
@@ -112,6 +116,7 @@ where
     }
 }
 
+#[cfg(has_num_saturating)]
 impl<T: ConstZero> ConstZero for Saturating<T>
 where
     Saturating<T>: Add<Output = Saturating<T>>,
@@ -220,6 +225,7 @@ where
     const ONE: Self = Wrapping(T::ONE);
 }
 
+#[cfg(has_num_saturating)]
 impl<T: One> One for Saturating<T>
 where
     Saturating<T>: Mul<Output = Saturating<T>>,
@@ -233,6 +239,7 @@ where
     }
 }
 
+#[cfg(has_num_saturating)]
 impl<T: ConstOne> ConstOne for Saturating<T>
 where
     Saturating<T>: Mul<Output = Saturating<T>>,
@@ -282,6 +289,7 @@ fn wrapping_is_one() {
 }
 
 #[test]
+#[cfg(has_num_saturating)]
 fn saturating_identities() {
     macro_rules! test_saturating_identities {
         ($($t:ty)+) => {
@@ -298,11 +306,13 @@ fn saturating_identities() {
 }
 
 #[test]
+#[cfg(has_num_saturating)]
 fn saturating_is_zero() {
     fn require_zero<T: Zero>(_: &T) {}
     require_zero(&Saturating(42));
 }
 #[test]
+#[cfg(has_num_saturating)]
 fn saturating_is_one() {
     fn require_one<T: One>(_: &T) {}
     require_one(&Saturating(42));

src/lib.rs

@@ -184,6 +184,7 @@ where
     }
 }
 
+#[cfg(has_num_saturating)]
 impl<T: Num> Num for core::num::Saturating<T>
 where
     core::num::Saturating<T>: NumOps,
@@ -581,13 +582,15 @@ fn wrapping_from_str_radix() {
 }
 
 #[test]
+#[cfg(has_num_saturating)]
 fn saturating_is_num() {
     fn require_num<T: Num>(_: &T) {}
     require_num(&core::num::Saturating(42_u32));
     require_num(&core::num::Saturating(-42));
 }
 
 #[test]
+#[cfg(has_num_saturating)]
 fn saturating_from_str_radix() {
     macro_rules! test_saturating_from_str_radix {
         ($($t:ty)+) => {