Rollup merge of rust-lang#93293 - nvzqz:nonzero-min-max, r=joshtriplett

Implement `MIN`/`MAX` constants for non-zero integers

This adds the associated [`MIN`](https://doc.rust-lang.org/stable/std/primitive.usize.html#associatedconstant.MIN)/[`MAX`](https://doc.rust-lang.org/stable/std/primitive.usize.html#associatedconstant.MAX) constants to `NonZero{U,I}{8,16,32,64,128,size}`, requested in rust-lang#89065.

This reimplements rust-lang#89077 due that PR being stagnant for 4 months. I am fine with closing this in favor of that one if the author revisits it. If so, I'd like to see that PR have the docs link to the `$Int`'s constants.

library/core/src/num/nonzero.rs

@@ -989,3 +989,104 @@ macro_rules! nonzero_unsigned_is_power_of_two {
 }
 
 nonzero_unsigned_is_power_of_two! { NonZeroU8 NonZeroU16 NonZeroU32 NonZeroU64 NonZeroU128 NonZeroUsize }
+
+macro_rules! nonzero_min_max_unsigned {
+    ( $( $Ty: ident($Int: ident); )+ ) => {
+        $(
+            impl $Ty {
+                /// The smallest value that can be represented by this non-zero
+                /// integer type, 1.
+                ///
+                /// # Examples
+                ///
+                /// ```
+                /// #![feature(nonzero_min_max)]
+                #[doc = concat!("# use std::num::", stringify!($Ty), ";")]
+                ///
+                #[doc = concat!("assert_eq!(", stringify!($Ty), "::MIN.get(), 1", stringify!($Int), ");")]
+                /// ```
+                #[unstable(feature = "nonzero_min_max", issue = "89065")]
+                pub const MIN: Self = Self::new(1).unwrap();
+
+                /// The largest value that can be represented by this non-zero
+                /// integer type,
+                #[doc = concat!("equal to [`", stringify!($Int), "::MAX`].")]
+                ///
+                /// # Examples
+                ///
+                /// ```
+                /// #![feature(nonzero_min_max)]
+                #[doc = concat!("# use std::num::", stringify!($Ty), ";")]
+                ///
+                #[doc = concat!("assert_eq!(", stringify!($Ty), "::MAX.get(), ", stringify!($Int), "::MAX);")]
+                /// ```
+                #[unstable(feature = "nonzero_min_max", issue = "89065")]
+                pub const MAX: Self = Self::new(<$Int>::MAX).unwrap();
+            }
+        )+
+    }
+}
+
+macro_rules! nonzero_min_max_signed {
+    ( $( $Ty: ident($Int: ident); )+ ) => {
+        $(
+            impl $Ty {
+                /// The smallest value that can be represented by this non-zero
+                /// integer type,
+                #[doc = concat!("equal to [`", stringify!($Int), "::MIN`].")]
+                ///
+                /// Note: While most integer types are defined for every whole
+                /// number between `MIN` and `MAX`, signed non-zero integers are
+                /// a special case. They have a "gap" at 0.
+                ///
+                /// # Examples
+                ///
+                /// ```
+                /// #![feature(nonzero_min_max)]
+                #[doc = concat!("# use std::num::", stringify!($Ty), ";")]
+                ///
+                #[doc = concat!("assert_eq!(", stringify!($Ty), "::MIN.get(), ", stringify!($Int), "::MIN);")]
+                /// ```
+                #[unstable(feature = "nonzero_min_max", issue = "89065")]
+                pub const MIN: Self = Self::new(<$Int>::MIN).unwrap();
+
+                /// The largest value that can be represented by this non-zero
+                /// integer type,
+                #[doc = concat!("equal to [`", stringify!($Int), "::MAX`].")]
+                ///
+                /// Note: While most integer types are defined for every whole
+                /// number between `MIN` and `MAX`, signed non-zero integers are
+                /// a special case. They have a "gap" at 0.
+                ///
+                /// # Examples
+                ///
+                /// ```
+                /// #![feature(nonzero_min_max)]
+                #[doc = concat!("# use std::num::", stringify!($Ty), ";")]
+                ///
+                #[doc = concat!("assert_eq!(", stringify!($Ty), "::MAX.get(), ", stringify!($Int), "::MAX);")]
+                /// ```
+                #[unstable(feature = "nonzero_min_max", issue = "89065")]
+                pub const MAX: Self = Self::new(<$Int>::MAX).unwrap();
+            }
+        )+
+    }
+}
+
+nonzero_min_max_unsigned! {
+    NonZeroU8(u8);
+    NonZeroU16(u16);
+    NonZeroU32(u32);
+    NonZeroU64(u64);
+    NonZeroU128(u128);
+    NonZeroUsize(usize);
+}
+
+nonzero_min_max_signed! {
+    NonZeroI8(i8);
+    NonZeroI16(i16);
+    NonZeroI32(i32);
+    NonZeroI64(i64);
+    NonZeroI128(i128);
+    NonZeroIsize(isize);
+}