Rollup merge of #121277 - reitermarkus:generic-nonzero-convert-num, r=dtolnay

Refactor trait implementations in `core::convert::num`.

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

Implement conversion traits using generic `NonZero` type, and refactor all macros to use a consistent format/order of parameters.

r? `@dtolnay`

1 files changed, 325 insertions, 367 deletions

diff --git a/library/core/src/convert/num.rs b/library/core/src/convert/num.rs
index 08dc8f48dfe..46a9006c146 100644
--- a/library/core/src/convert/num.rs
+++ b/library/core/src/convert/num.rs
@@ -19,7 +19,7 @@ pub trait FloatToInt<Int>: private::Sealed + Sized {
 }
 
 macro_rules! impl_float_to_int {
-    ( $Float: ident => $( $Int: ident )+ ) => {
+    ($Float:ty => $($Int:ty),+) => {
         #[unstable(feature = "convert_float_to_int", issue = "67057")]
         impl private::Sealed for $Float {}
         $(
@@ -35,14 +35,38 @@ macro_rules! impl_float_to_int {
     }
 }
 
-impl_float_to_int!(f32 => u8 u16 u32 u64 u128 usize i8 i16 i32 i64 i128 isize);
-impl_float_to_int!(f64 => u8 u16 u32 u64 u128 usize i8 i16 i32 i64 i128 isize);
+impl_float_to_int!(f32 => u8, u16, u32, u64, u128, usize, i8, i16, i32, i64, i128, isize);
+impl_float_to_int!(f64 => u8, u16, u32, u64, u128, usize, i8, i16, i32, i64, i128, isize);
 
 // Conversion traits for primitive integer and float types
 // Conversions T -> T are covered by a blanket impl and therefore excluded
 // Some conversions from and to usize/isize are not implemented due to portability concerns
 macro_rules! impl_from {
-    ($Small: ty, $Large: ty, #[$attr:meta], $doc: expr) => {
+    (bool => $Int:ty $(,)?) => {
+        impl_from!(
+            bool => $Int,
+            #[stable(feature = "from_bool", since = "1.28.0")],
+            concat!(
+                "Converts a [`bool`] to [`", stringify!($Int), "`] losslessly.\n",
+                "The resulting value is `0` for `false` and `1` for `true` values.\n",
+                "\n",
+                "# Examples\n",
+                "\n",
+                "```\n",
+                "assert_eq!(", stringify!($Int), "::from(true), 1);\n",
+                "assert_eq!(", stringify!($Int), "::from(false), 0);\n",
+                "```\n",
+            ),
+        );
+    };
+    ($Small:ty => $Large:ty, #[$attr:meta] $(,)?) => {
+        impl_from!(
+            $Small => $Large,
+            #[$attr],
+            concat!("Converts [`", stringify!($Small), "`] to [`", stringify!($Large), "`] losslessly."),
+        );
+    };
+    ($Small:ty => $Large:ty, #[$attr:meta], $doc:expr $(,)?) => {
         #[$attr]
         impl From<$Small> for $Large {
             // Rustdocs on the impl block show a "[+] show undocumented items" toggle.
@@ -54,91 +78,66 @@ macro_rules! impl_from {
             }
         }
     };
-    ($Small: ty, $Large: ty, #[$attr:meta]) => {
-        impl_from!($Small,
-                   $Large,
-                   #[$attr],
-                   concat!("Converts `",
-                           stringify!($Small),
-                           "` to `",
-                           stringify!($Large),
-                           "` losslessly."));
-    }
 }
 
-macro_rules! impl_from_bool {
-    ($target: ty, #[$attr:meta]) => {
-        impl_from!(bool, $target, #[$attr], concat!("Converts a `bool` to a `",
-            stringify!($target), "`. The resulting value is `0` for `false` and `1` for `true`
-values.
-
-# Examples
-
-```
-assert_eq!(", stringify!($target), "::from(true), 1);
-assert_eq!(", stringify!($target), "::from(false), 0);
-```"));
-    };
-}
-
-// Bool -> Any
-impl_from_bool! { u8, #[stable(feature = "from_bool", since = "1.28.0")] }
-impl_from_bool! { u16, #[stable(feature = "from_bool", since = "1.28.0")] }
-impl_from_bool! { u32, #[stable(feature = "from_bool", since = "1.28.0")] }
-impl_from_bool! { u64, #[stable(feature = "from_bool", since = "1.28.0")] }
-impl_from_bool! { u128, #[stable(feature = "from_bool", since = "1.28.0")] }
-impl_from_bool! { usize, #[stable(feature = "from_bool", since = "1.28.0")] }
-impl_from_bool! { i8, #[stable(feature = "from_bool", since = "1.28.0")] }
-impl_from_bool! { i16, #[stable(feature = "from_bool", since = "1.28.0")] }
-impl_from_bool! { i32, #[stable(feature = "from_bool", since = "1.28.0")] }
-impl_from_bool! { i64, #[stable(feature = "from_bool", since = "1.28.0")] }
-impl_from_bool! { i128, #[stable(feature = "from_bool", since = "1.28.0")] }
-impl_from_bool! { isize, #[stable(feature = "from_bool", since = "1.28.0")] }
-
-// Unsigned -> Unsigned
-impl_from! { u8, u16, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u8, u32, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u8, u64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u8, u128, #[stable(feature = "i128", since = "1.26.0")] }
-impl_from! { u8, usize, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u16, u32, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u16, u64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u16, u128, #[stable(feature = "i128", since = "1.26.0")] }
-impl_from! { u32, u64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u32, u128, #[stable(feature = "i128", since = "1.26.0")] }
-impl_from! { u64, u128, #[stable(feature = "i128", since = "1.26.0")] }
-
-// Signed -> Signed
-impl_from! { i8, i16, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { i8, i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { i8, i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { i8, i128, #[stable(feature = "i128", since = "1.26.0")] }
-impl_from! { i8, isize, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { i16, i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { i16, i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { i16, i128, #[stable(feature = "i128", since = "1.26.0")] }
-impl_from! { i32, i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { i32, i128, #[stable(feature = "i128", since = "1.26.0")] }
-impl_from! { i64, i128, #[stable(feature = "i128", since = "1.26.0")] }
-
-// Unsigned -> Signed
-impl_from! { u8, i16, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u8, i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u8, i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u8, i128, #[stable(feature = "i128", since = "1.26.0")] }
-impl_from! { u16, i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u16, i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u16, i128, #[stable(feature = "i128", since = "1.26.0")] }
-impl_from! { u32, i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u32, i128, #[stable(feature = "i128", since = "1.26.0")] }
-impl_from! { u64, i128, #[stable(feature = "i128", since = "1.26.0")] }
+// boolean -> integer
+impl_from!(bool => u8);
+impl_from!(bool => u16);
+impl_from!(bool => u32);
+impl_from!(bool => u64);
+impl_from!(bool => u128);
+impl_from!(bool => usize);
+impl_from!(bool => i8);
+impl_from!(bool => i16);
+impl_from!(bool => i32);
+impl_from!(bool => i64);
+impl_from!(bool => i128);
+impl_from!(bool => isize);
+
+// unsigned integer -> unsigned integer
+impl_from!(u8 => u16, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
+impl_from!(u8 => u32, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
+impl_from!(u8 => u64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
+impl_from!(u8 => u128, #[stable(feature = "i128", since = "1.26.0")]);
+impl_from!(u8 => usize, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
+impl_from!(u16 => u32, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
+impl_from!(u16 => u64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
+impl_from!(u16 => u128, #[stable(feature = "i128", since = "1.26.0")]);
+impl_from!(u32 => u64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
+impl_from!(u32 => u128, #[stable(feature = "i128", since = "1.26.0")]);
+impl_from!(u64 => u128, #[stable(feature = "i128", since = "1.26.0")]);
+
+// signed integer -> signed integer
+impl_from!(i8 => i16, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
+impl_from!(i8 => i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
+impl_from!(i8 => i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
+impl_from!(i8 => i128, #[stable(feature = "i128", since = "1.26.0")]);
+impl_from!(i8 => isize, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
+impl_from!(i16 => i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
+impl_from!(i16 => i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
+impl_from!(i16 => i128, #[stable(feature = "i128", since = "1.26.0")]);
+impl_from!(i32 => i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
+impl_from!(i32 => i128, #[stable(feature = "i128", since = "1.26.0")]);
+impl_from!(i64 => i128, #[stable(feature = "i128", since = "1.26.0")]);
+
+// unsigned integer -> signed integer
+impl_from!(u8 => i16, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
+impl_from!(u8 => i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
+impl_from!(u8 => i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
+impl_from!(u8 => i128, #[stable(feature = "i128", since = "1.26.0")]);
+impl_from!(u16 => i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
+impl_from!(u16 => i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
+impl_from!(u16 => i128, #[stable(feature = "i128", since = "1.26.0")]);
+impl_from!(u32 => i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
+impl_from!(u32 => i128, #[stable(feature = "i128", since = "1.26.0")]);
+impl_from!(u64 => i128, #[stable(feature = "i128", since = "1.26.0")]);
 
 // The C99 standard defines bounds on INTPTR_MIN, INTPTR_MAX, and UINTPTR_MAX
 // which imply that pointer-sized integers must be at least 16 bits:
 // https://port70.net/~nsz/c/c99/n1256.html#7.18.2.4
-impl_from! { u16, usize, #[stable(feature = "lossless_iusize_conv", since = "1.26.0")] }
-impl_from! { u8, isize, #[stable(feature = "lossless_iusize_conv", since = "1.26.0")] }
-impl_from! { i16, isize, #[stable(feature = "lossless_iusize_conv", since = "1.26.0")] }
+impl_from!(u16 => usize, #[stable(feature = "lossless_iusize_conv", since = "1.26.0")]);
+impl_from!(u8 => isize, #[stable(feature = "lossless_iusize_conv", since = "1.26.0")]);
+impl_from!(i16 => isize, #[stable(feature = "lossless_iusize_conv", since = "1.26.0")]);
 
 // RISC-V defines the possibility of a 128-bit address space (RV128).
 
@@ -150,66 +149,54 @@ impl_from! { i16, isize, #[stable(feature = "lossless_iusize_conv", since = "1.2
 // they fit in the significand, which is 24 bits in f32 and 53 bits in f64.
 // Lossy float conversions are not implemented at this time.
 
-// Signed -> Float
-impl_from! { i8, f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
-impl_from! { i8, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
-impl_from! { i16, f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
-impl_from! { i16, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
-impl_from! { i32, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
-
-// Unsigned -> Float
-impl_from! { u8, f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
-impl_from! { u8, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
-impl_from! { u16, f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
-impl_from! { u16, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
-impl_from! { u32, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
-
-// Float -> Float
-impl_from! { f32, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
-
-// bool -> Float
-#[stable(feature = "float_from_bool", since = "1.68.0")]
-impl From<bool> for f32 {
-    /// Converts `bool` to `f32` losslessly. The resulting value is positive
-    /// `0.0` for `false` and `1.0` for `true` values.
-    ///
-    /// # Examples
-    /// ```
-    /// let x: f32 = false.into();
-    /// assert_eq!(x, 0.0);
-    /// assert!(x.is_sign_positive());
-    ///
-    /// let y: f32 = true.into();
-    /// assert_eq!(y, 1.0);
-    /// ```
-    #[inline]
-    fn from(small: bool) -> Self {
-        small as u8 as Self
-    }
-}
-#[stable(feature = "float_from_bool", since = "1.68.0")]
-impl From<bool> for f64 {
-    /// Converts `bool` to `f64` losslessly. The resulting value is positive
-    /// `0.0` for `false` and `1.0` for `true` values.
-    ///
-    /// # Examples
-    /// ```
-    /// let x: f64 = false.into();
-    /// assert_eq!(x, 0.0);
-    /// assert!(x.is_sign_positive());
-    ///
-    /// let y: f64 = true.into();
-    /// assert_eq!(y, 1.0);
-    /// ```
-    #[inline]
-    fn from(small: bool) -> Self {
-        small as u8 as Self
-    }
+// signed integer -> float
+impl_from!(i8 => f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
+impl_from!(i8 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
+impl_from!(i16 => f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
+impl_from!(i16 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
+impl_from!(i32 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
+
+// unsigned integer -> float
+impl_from!(u8 => f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
+impl_from!(u8 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
+impl_from!(u16 => f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
+impl_from!(u16 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
+impl_from!(u32 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
+
+// float -> float
+impl_from!(f32 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
+
+macro_rules! impl_float_from_bool {
+    ($float:ty) => {
+        #[stable(feature = "float_from_bool", since = "1.68.0")]
+        impl From<bool> for $float {
+            #[doc = concat!("Converts a [`bool`] to [`", stringify!($float),"`] losslessly.")]
+            /// The resulting value is positive `0.0` for `false` and `1.0` for `true` values.
+            ///
+            /// # Examples
+            /// ```
+            #[doc = concat!("let x: ", stringify!($float)," = false.into();")]
+            /// assert_eq!(x, 0.0);
+            /// assert!(x.is_sign_positive());
+            ///
+            #[doc = concat!("let y: ", stringify!($float)," = true.into();")]
+            /// assert_eq!(y, 1.0);
+            /// ```
+            #[inline]
+            fn from(small: bool) -> Self {
+                small as u8 as Self
+            }
+        }
+    };
 }
 
+// boolean -> float
+impl_float_from_bool!(f32);
+impl_float_from_bool!(f64);
+
 // no possible bounds violation
-macro_rules! try_from_unbounded {
-    ($source:ty, $($target:ty),*) => {$(
+macro_rules! impl_try_from_unbounded {
+    ($source:ty => $($target:ty),+) => {$(
         #[stable(feature = "try_from", since = "1.34.0")]
         impl TryFrom<$source> for $target {
             type Error = TryFromIntError;
@@ -226,8 +213,8 @@ macro_rules! try_from_unbounded {
 }
 
 // only negative bounds
-macro_rules! try_from_lower_bounded {
-    ($source:ty, $($target:ty),*) => {$(
+macro_rules! impl_try_from_lower_bounded {
+    ($source:ty => $($target:ty),+) => {$(
         #[stable(feature = "try_from", since = "1.34.0")]
         impl TryFrom<$source> for $target {
             type Error = TryFromIntError;
@@ -248,8 +235,8 @@ macro_rules! try_from_lower_bounded {
 }
 
 // unsigned to signed (only positive bound)
-macro_rules! try_from_upper_bounded {
-    ($source:ty, $($target:ty),*) => {$(
+macro_rules! impl_try_from_upper_bounded {
+    ($source:ty => $($target:ty),+) => {$(
         #[stable(feature = "try_from", since = "1.34.0")]
         impl TryFrom<$source> for $target {
             type Error = TryFromIntError;
@@ -270,8 +257,8 @@ macro_rules! try_from_upper_bounded {
 }
 
 // all other cases
-macro_rules! try_from_both_bounded {
-    ($source:ty, $($target:ty),*) => {$(
+macro_rules! impl_try_from_both_bounded {
+    ($source:ty => $($target:ty),+) => {$(
         #[stable(feature = "try_from", since = "1.34.0")]
         impl TryFrom<$source> for $target {
             type Error = TryFromIntError;
@@ -294,65 +281,66 @@ macro_rules! try_from_both_bounded {
 }
 
 macro_rules! rev {
-    ($mac:ident, $source:ty, $($target:ty),*) => {$(
-        $mac!($target, $source);
+    ($mac:ident, $source:ty => $($target:ty),+) => {$(
+        $mac!($target => $source);
     )*}
 }
 
-// intra-sign conversions
-try_from_upper_bounded!(u16, u8);
-try_from_upper_bounded!(u32, u16, u8);
-try_from_upper_bounded!(u64, u32, u16, u8);
-try_from_upper_bounded!(u128, u64, u32, u16, u8);
-
-try_from_both_bounded!(i16, i8);
-try_from_both_bounded!(i32, i16, i8);
-try_from_both_bounded!(i64, i32, i16, i8);
-try_from_both_bounded!(i128, i64, i32, i16, i8);
-
-// unsigned-to-signed
-try_from_upper_bounded!(u8, i8);
-try_from_upper_bounded!(u16, i8, i16);
-try_from_upper_bounded!(u32, i8, i16, i32);
-try_from_upper_bounded!(u64, i8, i16, i32, i64);
-try_from_upper_bounded!(u128, i8, i16, i32, i64, i128);
-
-// signed-to-unsigned
-try_from_lower_bounded!(i8, u8, u16, u32, u64, u128);
-try_from_lower_bounded!(i16, u16, u32, u64, u128);
-try_from_lower_bounded!(i32, u32, u64, u128);
-try_from_lower_bounded!(i64, u64, u128);
-try_from_lower_bounded!(i128, u128);
-try_from_both_bounded!(i16, u8);
-try_from_both_bounded!(i32, u16, u8);
-try_from_both_bounded!(i64, u32, u16, u8);
-try_from_both_bounded!(i128, u64, u32, u16, u8);
+// unsigned integer -> unsigned integer
+impl_try_from_upper_bounded!(u16 => u8);
+impl_try_from_upper_bounded!(u32 => u8, u16);
+impl_try_from_upper_bounded!(u64 => u8, u16, u32);
+impl_try_from_upper_bounded!(u128 => u8, u16, u32, u64);
+
+// signed integer -> signed integer
+impl_try_from_both_bounded!(i16 => i8);
+impl_try_from_both_bounded!(i32 => i8, i16);
+impl_try_from_both_bounded!(i64 => i8, i16, i32);
+impl_try_from_both_bounded!(i128 => i8, i16, i32, i64);
+
+// unsigned integer -> signed integer
+impl_try_from_upper_bounded!(u8 => i8);
+impl_try_from_upper_bounded!(u16 => i8, i16);
+impl_try_from_upper_bounded!(u32 => i8, i16, i32);
+impl_try_from_upper_bounded!(u64 => i8, i16, i32, i64);
+impl_try_from_upper_bounded!(u128 => i8, i16, i32, i64, i128);
+
+// signed integer -> unsigned integer
+impl_try_from_lower_bounded!(i8 => u8, u16, u32, u64, u128);
+impl_try_from_both_bounded!(i16 => u8);
+impl_try_from_lower_bounded!(i16 => u16, u32, u64, u128);
+impl_try_from_both_bounded!(i32 => u8, u16);
+impl_try_from_lower_bounded!(i32 => u32, u64, u128);
+impl_try_from_both_bounded!(i64 => u8, u16, u32);
+impl_try_from_lower_bounded!(i64 => u64, u128);
+impl_try_from_both_bounded!(i128 => u8, u16, u32, u64);
+impl_try_from_lower_bounded!(i128 => u128);
 
 // usize/isize
-try_from_upper_bounded!(usize, isize);
-try_from_lower_bounded!(isize, usize);
+impl_try_from_upper_bounded!(usize => isize);
+impl_try_from_lower_bounded!(isize => usize);
 
 #[cfg(target_pointer_width = "16")]
 mod ptr_try_from_impls {
     use super::TryFromIntError;
     use crate::convert::TryFrom;
 
-    try_from_upper_bounded!(usize, u8);
-    try_from_unbounded!(usize, u16, u32, u64, u128);
-    try_from_upper_bounded!(usize, i8, i16);
-    try_from_unbounded!(usize, i32, i64, i128);
+    impl_try_from_upper_bounded!(usize => u8);
+    impl_try_from_unbounded!(usize => u16, u32, u64, u128);
+    impl_try_from_upper_bounded!(usize => i8, i16);
+    impl_try_from_unbounded!(usize => i32, i64, i128);
 
-    try_from_both_bounded!(isize, u8);
-    try_from_lower_bounded!(isize, u16, u32, u64, u128);
-    try_from_both_bounded!(isize, i8);
-    try_from_unbounded!(isize, i16, i32, i64, i128);
+    impl_try_from_both_bounded!(isize => u8);
+    impl_try_from_lower_bounded!(isize => u16, u32, u64, u128);
+    impl_try_from_both_bounded!(isize => i8);
+    impl_try_from_unbounded!(isize => i16, i32, i64, i128);
 
-    rev!(try_from_upper_bounded, usize, u32, u64, u128);
-    rev!(try_from_lower_bounded, usize, i8, i16);
-    rev!(try_from_both_bounded, usize, i32, i64, i128);
+    rev!(impl_try_from_upper_bounded, usize => u32, u64, u128);
+    rev!(impl_try_from_lower_bounded, usize => i8, i16);
+    rev!(impl_try_from_both_bounded, usize => i32, i64, i128);
 
-    rev!(try_from_upper_bounded, isize, u16, u32, u64, u128);
-    rev!(try_from_both_bounded, isize, i32, i64, i128);
+    rev!(impl_try_from_upper_bounded, isize => u16, u32, u64, u128);
+    rev!(impl_try_from_both_bounded, isize => i32, i64, i128);
 }
 
 #[cfg(target_pointer_width = "32")]
@@ -360,25 +348,25 @@ mod ptr_try_from_impls {
     use super::TryFromIntError;
     use crate::convert::TryFrom;
 
-    try_from_upper_bounded!(usize, u8, u16);
-    try_from_unbounded!(usize, u32, u64, u128);
-    try_from_upper_bounded!(usize, i8, i16, i32);
-    try_from_unbounded!(usize, i64, i128);
-
-    try_from_both_bounded!(isize, u8, u16);
-    try_from_lower_bounded!(isize, u32, u64, u128);
-    try_from_both_bounded!(isize, i8, i16);
-    try_from_unbounded!(isize, i32, i64, i128);
-
-    rev!(try_from_unbounded, usize, u32);
-    rev!(try_from_upper_bounded, usize, u64, u128);
-    rev!(try_from_lower_bounded, usize, i8, i16, i32);
-    rev!(try_from_both_bounded, usize, i64, i128);
-
-    rev!(try_from_unbounded, isize, u16);
-    rev!(try_from_upper_bounded, isize, u32, u64, u128);
-    rev!(try_from_unbounded, isize, i32);
-    rev!(try_from_both_bounded, isize, i64, i128);
+    impl_try_from_upper_bounded!(usize => u8, u16);
+    impl_try_from_unbounded!(usize => u32, u64, u128);
+    impl_try_from_upper_bounded!(usize => i8, i16, i32);
+    impl_try_from_unbounded!(usize => i64, i128);
+
+    impl_try_from_both_bounded!(isize => u8, u16);
+    impl_try_from_lower_bounded!(isize => u32, u64, u128);
+    impl_try_from_both_bounded!(isize => i8, i16);
+    impl_try_from_unbounded!(isize => i32, i64, i128);
+
+    rev!(impl_try_from_unbounded, usize => u32);
+    rev!(impl_try_from_upper_bounded, usize => u64, u128);
+    rev!(impl_try_from_lower_bounded, usize => i8, i16, i32);
+    rev!(impl_try_from_both_bounded, usize => i64, i128);
+
+    rev!(impl_try_from_unbounded, isize => u16);
+    rev!(impl_try_from_upper_bounded, isize => u32, u64, u128);
+    rev!(impl_try_from_unbounded, isize => i32);
+    rev!(impl_try_from_both_bounded, isize => i64, i128);
 }
 
 #[cfg(target_pointer_width = "64")]
@@ -386,195 +374,165 @@ mod ptr_try_from_impls {
     use super::TryFromIntError;
     use crate::convert::TryFrom;
 
-    try_from_upper_bounded!(usize, u8, u16, u32);
-    try_from_unbounded!(usize, u64, u128);
-    try_from_upper_bounded!(usize, i8, i16, i32, i64);
-    try_from_unbounded!(usize, i128);
-
-    try_from_both_bounded!(isize, u8, u16, u32);
-    try_from_lower_bounded!(isize, u64, u128);
-    try_from_both_bounded!(isize, i8, i16, i32);
-    try_from_unbounded!(isize, i64, i128);
-
-    rev!(try_from_unbounded, usize, u32, u64);
-    rev!(try_from_upper_bounded, usize, u128);
-    rev!(try_from_lower_bounded, usize, i8, i16, i32, i64);
-    rev!(try_from_both_bounded, usize, i128);
-
-    rev!(try_from_unbounded, isize, u16, u32);
-    rev!(try_from_upper_bounded, isize, u64, u128);
-    rev!(try_from_unbounded, isize, i32, i64);
-    rev!(try_from_both_bounded, isize, i128);
+    impl_try_from_upper_bounded!(usize => u8, u16, u32);
+    impl_try_from_unbounded!(usize => u64, u128);
+    impl_try_from_upper_bounded!(usize => i8, i16, i32, i64);
+    impl_try_from_unbounded!(usize => i128);
+
+    impl_try_from_both_bounded!(isize => u8, u16, u32);
+    impl_try_from_lower_bounded!(isize => u64, u128);
+    impl_try_from_both_bounded!(isize => i8, i16, i32);
+    impl_try_from_unbounded!(isize => i64, i128);
+
+    rev!(impl_try_from_unbounded, usize => u32, u64);
+    rev!(impl_try_from_upper_bounded, usize => u128);
+    rev!(impl_try_from_lower_bounded, usize => i8, i16, i32, i64);
+    rev!(impl_try_from_both_bounded, usize => i128);
+
+    rev!(impl_try_from_unbounded, isize => u16, u32);
+    rev!(impl_try_from_upper_bounded, isize => u64, u128);
+    rev!(impl_try_from_unbounded, isize => i32, i64);
+    rev!(impl_try_from_both_bounded, isize => i128);
 }
 
 // Conversion traits for non-zero integer types
-use crate::num::NonZeroI128;
-use crate::num::NonZeroI16;
-use crate::num::NonZeroI32;
-use crate::num::NonZeroI64;
-use crate::num::NonZeroI8;
-use crate::num::NonZeroIsize;
-use crate::num::NonZeroU128;
-use crate::num::NonZeroU16;
-use crate::num::NonZeroU32;
-use crate::num::NonZeroU64;
-use crate::num::NonZeroU8;
-use crate::num::NonZeroUsize;
-
-macro_rules! nzint_impl_from {
-    ($Small: ty, $Large: ty, #[$attr:meta], $doc: expr) => {
-        #[$attr]
-        impl From<$Small> for $Large {
+use crate::num::NonZero;
+
+macro_rules! impl_nonzero_int_from_nonzero_int {
+    ($Small:ty => $Large:ty) => {
+        #[stable(feature = "nz_int_conv", since = "1.41.0")]
+        impl From<NonZero<$Small>> for NonZero<$Large> {
             // Rustdocs on the impl block show a "[+] show undocumented items" toggle.
             // Rustdocs on functions do not.
-            #[doc = $doc]
+            #[doc = concat!("Converts <code>[NonZero]\\<[", stringify!($Small), "]></code> ")]
+            #[doc = concat!("to <code>[NonZero]\\<[", stringify!($Large), "]></code> losslessly.")]
             #[inline]
-            fn from(small: $Small) -> Self {
+            fn from(small: NonZero<$Small>) -> Self {
                 // SAFETY: input type guarantees the value is non-zero
-                unsafe {
-                    Self::new_unchecked(From::from(small.get()))
-                }
+                unsafe { Self::new_unchecked(From::from(small.get())) }
             }
         }
     };
-    ($Small: ty, $Large: ty, #[$attr:meta]) => {
-        nzint_impl_from!($Small,
-                   $Large,
-                   #[$attr],
-                   concat!("Converts `",
-                           stringify!($Small),
-                           "` to `",
-                           stringify!($Large),
-                           "` losslessly."));
-    }
 }
 
-// Non-zero Unsigned -> Non-zero Unsigned
-nzint_impl_from! { NonZeroU8, NonZeroU16, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroU8, NonZeroU32, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroU8, NonZeroU64, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroU8, NonZeroU128, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroU8, NonZeroUsize, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroU16, NonZeroU32, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroU16, NonZeroU64, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroU16, NonZeroU128, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroU16, NonZeroUsize, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroU32, NonZeroU64, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroU32, NonZeroU128, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroU64, NonZeroU128, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-
-// Non-zero Signed -> Non-zero Signed
-nzint_impl_from! { NonZeroI8, NonZeroI16, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroI8, NonZeroI32, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroI8, NonZeroI64, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroI8, NonZeroI128, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroI8, NonZeroIsize, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroI16, NonZeroI32, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroI16, NonZeroI64, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroI16, NonZeroI128, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroI16, NonZeroIsize, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroI32, NonZeroI64, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroI32, NonZeroI128, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroI64, NonZeroI128, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-
-// NonZero UnSigned -> Non-zero Signed
-nzint_impl_from! { NonZeroU8, NonZeroI16, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroU8, NonZeroI32, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroU8, NonZeroI64, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroU8, NonZeroI128, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroU8, NonZeroIsize, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroU16, NonZeroI32, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroU16, NonZeroI64, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroU16, NonZeroI128, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroU32, NonZeroI64, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroU32, NonZeroI128, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-nzint_impl_from! { NonZeroU64, NonZeroI128, #[stable(feature = "nz_int_conv", since = "1.41.0")] }
-
-macro_rules! nzint_impl_try_from_int {
-    ($Int: ty, $NonZeroInt: ty, #[$attr:meta], $doc: expr) => {
-        #[$attr]
-        impl TryFrom<$Int> for $NonZeroInt {
+// non-zero unsigned integer -> non-zero unsigned integer
+impl_nonzero_int_from_nonzero_int!(u8 => u16);
+impl_nonzero_int_from_nonzero_int!(u8 => u32);
+impl_nonzero_int_from_nonzero_int!(u8 => u64);
+impl_nonzero_int_from_nonzero_int!(u8 => u128);
+impl_nonzero_int_from_nonzero_int!(u8 => usize);
+impl_nonzero_int_from_nonzero_int!(u16 => u32);
+impl_nonzero_int_from_nonzero_int!(u16 => u64);
+impl_nonzero_int_from_nonzero_int!(u16 => u128);
+impl_nonzero_int_from_nonzero_int!(u16 => usize);
+impl_nonzero_int_from_nonzero_int!(u32 => u64);
+impl_nonzero_int_from_nonzero_int!(u32 => u128);
+impl_nonzero_int_from_nonzero_int!(u64 => u128);
+
+// non-zero signed integer -> non-zero signed integer
+impl_nonzero_int_from_nonzero_int!(i8 => i16);
+impl_nonzero_int_from_nonzero_int!(i8 => i32);
+impl_nonzero_int_from_nonzero_int!(i8 => i64);
+impl_nonzero_int_from_nonzero_int!(i8 => i128);
+impl_nonzero_int_from_nonzero_int!(i8 => isize);
+impl_nonzero_int_from_nonzero_int!(i16 => i32);
+impl_nonzero_int_from_nonzero_int!(i16 => i64);
+impl_nonzero_int_from_nonzero_int!(i16 => i128);
+impl_nonzero_int_from_nonzero_int!(i16 => isize);
+impl_nonzero_int_from_nonzero_int!(i32 => i64);
+impl_nonzero_int_from_nonzero_int!(i32 => i128);
+impl_nonzero_int_from_nonzero_int!(i64 => i128);
+
+// non-zero unsigned -> non-zero signed integer
+impl_nonzero_int_from_nonzero_int!(u8 => i16);
+impl_nonzero_int_from_nonzero_int!(u8 => i32);
+impl_nonzero_int_from_nonzero_int!(u8 => i64);
+impl_nonzero_int_from_nonzero_int!(u8 => i128);
+impl_nonzero_int_from_nonzero_int!(u8 => isize);
+impl_nonzero_int_from_nonzero_int!(u16 => i32);
+impl_nonzero_int_from_nonzero_int!(u16 => i64);
+impl_nonzero_int_from_nonzero_int!(u16 => i128);
+impl_nonzero_int_from_nonzero_int!(u32 => i64);
+impl_nonzero_int_from_nonzero_int!(u32 => i128);
+impl_nonzero_int_from_nonzero_int!(u64 => i128);
+
+macro_rules! impl_nonzero_int_try_from_int {
+    ($Int:ty) => {
+        #[stable(feature = "nzint_try_from_int_conv", since = "1.46.0")]
+        impl TryFrom<$Int> for NonZero<$Int> {
             type Error = TryFromIntError;
 
             // Rustdocs on the impl block show a "[+] show undocumented items" toggle.
             // Rustdocs on functions do not.
-            #[doc = $doc]
+            #[doc = concat!("Attempts to convert [`", stringify!($Int), "`] ")]
+            #[doc = concat!("to <code>[NonZero]\\<[", stringify!($Int), "]></code>.")]
             #[inline]
             fn try_from(value: $Int) -> Result<Self, Self::Error> {
                 Self::new(value).ok_or(TryFromIntError(()))
             }
         }
     };
-    ($Int: ty, $NonZeroInt: ty, #[$attr:meta]) => {
-        nzint_impl_try_from_int!($Int,
-                                 $NonZeroInt,
-                                 #[$attr],
-                                 concat!("Attempts to convert `",
-                                         stringify!($Int),
-                                         "` to `",
-                                         stringify!($NonZeroInt),
-                                         "`."));
-    }
 }
 
-// Int -> Non-zero Int
-nzint_impl_try_from_int! { u8, NonZeroU8, #[stable(feature = "nzint_try_from_int_conv", since = "1.46.0")] }
-nzint_impl_try_from_int! { u16, NonZeroU16, #[stable(feature = "nzint_try_from_int_conv", since = "1.46.0")] }
-nzint_impl_try_from_int! { u32, NonZeroU32, #[stable(feature = "nzint_try_from_int_conv", since = "1.46.0")] }
-nzint_impl_try_from_int! { u64, NonZeroU64, #[stable(feature = "nzint_try_from_int_conv", since = "1.46.0")] }
-nzint_impl_try_from_int! { u128, NonZeroU128, #[stable(feature = "nzint_try_from_int_conv", since = "1.46.0")] }
-nzint_impl_try_from_int! { usize, NonZeroUsize, #[stable(feature = "nzint_try_from_int_conv", since = "1.46.0")] }
-nzint_impl_try_from_int! { i8, NonZeroI8, #[stable(feature = "nzint_try_from_int_conv", since = "1.46.0")] }
-nzint_impl_try_from_int! { i16, NonZeroI16, #[stable(feature = "nzint_try_from_int_conv", since = "1.46.0")] }
-nzint_impl_try_from_int! { i32, NonZeroI32, #[stable(feature = "nzint_try_from_int_conv", since = "1.46.0")] }
-nzint_impl_try_from_int! { i64, NonZeroI64, #[stable(feature = "nzint_try_from_int_conv", since = "1.46.0")] }
-nzint_impl_try_from_int! { i128, NonZeroI128, #[stable(feature = "nzint_try_from_int_conv", since = "1.46.0")] }
-nzint_impl_try_from_int! { isize, NonZeroIsize, #[stable(feature = "nzint_try_from_int_conv", since = "1.46.0")] }
-
-macro_rules! nzint_impl_try_from_nzint {
-    ($From:ty => $To:ty, $doc: expr) => {
+// integer -> non-zero integer
+impl_nonzero_int_try_from_int!(u8);
+impl_nonzero_int_try_from_int!(u16);
+impl_nonzero_int_try_from_int!(u32);
+impl_nonzero_int_try_from_int!(u64);
+impl_nonzero_int_try_from_int!(u128);
+impl_nonzero_int_try_from_int!(usize);
+impl_nonzero_int_try_from_int!(i8);
+impl_nonzero_int_try_from_int!(i16);
+impl_nonzero_int_try_from_int!(i32);
+impl_nonzero_int_try_from_int!(i64);
+impl_nonzero_int_try_from_int!(i128);
+impl_nonzero_int_try_from_int!(isize);
+
+macro_rules! impl_nonzero_int_try_from_nonzero_int {
+    ($source:ty => $($target:ty),+) => {$(
         #[stable(feature = "nzint_try_from_nzint_conv", since = "1.49.0")]
-        impl TryFrom<$From> for $To {
+        impl TryFrom<NonZero<$source>> for NonZero<$target> {
             type Error = TryFromIntError;
 
             // Rustdocs on the impl block show a "[+] show undocumented items" toggle.
             // Rustdocs on functions do not.
-            #[doc = $doc]
+            #[doc = concat!("Attempts to convert <code>[NonZero]\\<[", stringify!($source), "]></code> ")]
+            #[doc = concat!("to <code>[NonZero]\\<[", stringify!($target), "]></code>.")]
             #[inline]
-            fn try_from(value: $From) -> Result<Self, Self::Error> {
-                TryFrom::try_from(value.get()).map(|v| {
-                    // SAFETY: $From is a NonZero type, so v is not zero.
-                    unsafe { Self::new_unchecked(v) }
-                })
+            fn try_from(value: NonZero<$source>) -> Result<Self, Self::Error> {
+                // SAFETY: Input is guaranteed to be non-zero.
+                Ok(unsafe { Self::new_unchecked(<$target>::try_from(value.get())?) })
             }
         }
-    };
-    ($To:ty: $($From: ty),*) => {$(
-        nzint_impl_try_from_nzint!(
-            $From => $To,
-            concat!(
-                "Attempts to convert `",
-                stringify!($From),
-                "` to `",
-                stringify!($To),
-                "`.",
-            )
-        );
     )*};
 }
 
-// Non-zero int -> non-zero unsigned int
-nzint_impl_try_from_nzint! { NonZeroU8: NonZeroI8, NonZeroU16, NonZeroI16, NonZeroU32, NonZeroI32, NonZeroU64, NonZeroI64, NonZeroU128, NonZeroI128, NonZeroUsize, NonZeroIsize }
-nzint_impl_try_from_nzint! { NonZeroU16: NonZeroI8, NonZeroI16, NonZeroU32, NonZeroI32, NonZeroU64, NonZeroI64, NonZeroU128, NonZeroI128, NonZeroUsize, NonZeroIsize }
-nzint_impl_try_from_nzint! { NonZeroU32: NonZeroI8, NonZeroI16, NonZeroI32, NonZeroU64, NonZeroI64, NonZeroU128, NonZeroI128, NonZeroUsize, NonZeroIsize }
-nzint_impl_try_from_nzint! { NonZeroU64: NonZeroI8, NonZeroI16, NonZeroI32, NonZeroI64, NonZeroU128, NonZeroI128, NonZeroUsize, NonZeroIsize }
-nzint_impl_try_from_nzint! { NonZeroU128: NonZeroI8, NonZeroI16, NonZeroI32, NonZeroI64, NonZeroI128, NonZeroUsize, NonZeroIsize }
-nzint_impl_try_from_nzint! { NonZeroUsize: NonZeroI8, NonZeroI16, NonZeroU32, NonZeroI32, NonZeroU64, NonZeroI64, NonZeroU128, NonZeroI128, NonZeroIsize }
-
-// Non-zero int -> non-zero signed int
-nzint_impl_try_from_nzint! { NonZeroI8: NonZeroU8, NonZeroU16, NonZeroI16, NonZeroU32, NonZeroI32, NonZeroU64, NonZeroI64, NonZeroU128, NonZeroI128, NonZeroUsize, NonZeroIsize }
-nzint_impl_try_from_nzint! { NonZeroI16: NonZeroU16, NonZeroU32, NonZeroI32, NonZeroU64, NonZeroI64, NonZeroU128, NonZeroI128, NonZeroUsize, NonZeroIsize }
-nzint_impl_try_from_nzint! { NonZeroI32: NonZeroU32, NonZeroU64, NonZeroI64, NonZeroU128, NonZeroI128, NonZeroUsize, NonZeroIsize }
-nzint_impl_try_from_nzint! { NonZeroI64: NonZeroU64, NonZeroU128, NonZeroI128, NonZeroUsize, NonZeroIsize }
-nzint_impl_try_from_nzint! { NonZeroI128: NonZeroU128, NonZeroUsize, NonZeroIsize }
-nzint_impl_try_from_nzint! { NonZeroIsize: NonZeroU16, NonZeroU32, NonZeroI32, NonZeroU64, NonZeroI64, NonZeroU128, NonZeroI128, NonZeroUsize }
+// unsigned non-zero integer -> unsigned non-zero integer
+impl_nonzero_int_try_from_nonzero_int!(u16 => u8);
+impl_nonzero_int_try_from_nonzero_int!(u32 => u8, u16, usize);
+impl_nonzero_int_try_from_nonzero_int!(u64 => u8, u16, u32, usize);
+impl_nonzero_int_try_from_nonzero_int!(u128 => u8, u16, u32, u64, usize);
+impl_nonzero_int_try_from_nonzero_int!(usize => u8, u16, u32, u64, u128);
+
+// signed non-zero integer -> signed non-zero integer
+impl_nonzero_int_try_from_nonzero_int!(i16 => i8);
+impl_nonzero_int_try_from_nonzero_int!(i32 => i8, i16, isize);
+impl_nonzero_int_try_from_nonzero_int!(i64 => i8, i16, i32, isize);
+impl_nonzero_int_try_from_nonzero_int!(i128 => i8, i16, i32, i64, isize);
+impl_nonzero_int_try_from_nonzero_int!(isize => i8, i16, i32, i64, i128);
+
+// unsigned non-zero integer -> signed non-zero integer
+impl_nonzero_int_try_from_nonzero_int!(u8 => i8);
+impl_nonzero_int_try_from_nonzero_int!(u16 => i8, i16, isize);
+impl_nonzero_int_try_from_nonzero_int!(u32 => i8, i16, i32, isize);
+impl_nonzero_int_try_from_nonzero_int!(u64 => i8, i16, i32, i64, isize);
+impl_nonzero_int_try_from_nonzero_int!(u128 => i8, i16, i32, i64, i128, isize);
+impl_nonzero_int_try_from_nonzero_int!(usize => i8, i16, i32, i64, i128, isize);
+
+// signed non-zero integer -> unsigned non-zero integer
+impl_nonzero_int_try_from_nonzero_int!(i8 => u8, u16, u32, u64, u128, usize);
+impl_nonzero_int_try_from_nonzero_int!(i16 => u8, u16, u32, u64, u128, usize);
+impl_nonzero_int_try_from_nonzero_int!(i32 => u8, u16, u32, u64, u128, usize);
+impl_nonzero_int_try_from_nonzero_int!(i64 => u8, u16, u32, u64, u128, usize);
+impl_nonzero_int_try_from_nonzero_int!(i128 => u8, u16, u32, u64, u128, usize);
+impl_nonzero_int_try_from_nonzero_int!(isize => u8, u16, u32, u64, u128, usize);