Clean up macros a little bit

src/num.rs

@@ -1,4 +1,6 @@
 //! Numeric Helper Traits
+//!
+//! Home to the numeric trait chain of doom, aka `Unsigned`
 #![allow(unused_comparisons)]
 use core::convert::TryFrom;
 use core::fmt::Debug;
@@ -52,6 +54,7 @@ pub trait Num:
     + Sub
     + SubAssign
 {
+    /// Implement absolute value function for unsigned numbers
     fn abs(self) -> Self {
         self
     }
@@ -112,10 +115,10 @@ pub trait Unsigned:
 /// A Trait representing signed integer primitives
 pub trait Signed: Int {}
 
-macro_rules! impl_num {
+macro_rules! impl_empty {
-    ($( $Type: ty ),* ) => {
+    ($Ident: ty, ($( $Type: ty ),*) ) => {
         $(
-            impl Num for $Type {}
+            impl $Ident for $Type {}
         )*
     }
 }
@@ -167,7 +170,7 @@ macro_rules! impl_unsigned {
         $(
             impl Unsigned for $Type {
                 /// Implementation based on
-                /// [https://en.wikipedia.org/wiki/Binary_GCD_algorithm](https://en.wikipedia.org/wiki/Binary_GCD_algorithm)
+                /// [Binary GCD algorithm](https://en.wikipedia.org/wiki/Binary_GCD_algorithm)
                 fn gcd(a: $Type, b: $Type) -> $Type {
                     if a == b {
                         return a;
@@ -214,15 +217,7 @@ macro_rules! impl_unsigned {
     };
 }
 
-macro_rules! impl_signed {
+impl_empty!(Num, (i8, u8, i16, u16, i32, u32, i64, u64, i128, u128, isize, usize));
-    ($($type: ty),* ) => {
-        $(
-            impl Signed for $type {}
-        )*
-    }
-}
-
-impl_num!(i8, u8, i16, u16, i32, u32, i64, u64, i128, u128, isize, usize);
 impl_int!(
     (i8, u8),
     (u8, u8),
@@ -238,7 +233,7 @@ impl_int!(
     (usize, usize)
 );
 impl_unsigned!(u8, u16, u32, u64, u128, usize);
-impl_signed!(i8, i16, i32, i64, i128, isize);
+impl_empty!(Signed, (i8, i16, i32, i64, i128, isize));
 
 #[cfg(test)]
 mod tests {