rename next_multiple_back_of as prev_multiple_of and test more

Author: strake

src/lib.rs

@@ -199,10 +199,14 @@ pub trait Integer: Sized + Num + PartialOrd + Ord + Eq {
     ///
     /// ~~~
     /// # use num_integer::Integer;
-    /// assert_eq!(16.next_multiple_of(& 8), 16);
-    /// assert_eq!(23.next_multiple_of(& 8), 24);
-    /// assert_eq!(16.next_multiple_of(&-8), 16);
-    /// assert_eq!(23.next_multiple_of(&-8), 16);
+    /// assert_eq!(( 16).next_multiple_of(& 8),  16);
+    /// assert_eq!(( 23).next_multiple_of(& 8),  24);
+    /// assert_eq!(( 16).next_multiple_of(&-8),  16);
+    /// assert_eq!(( 23).next_multiple_of(&-8),  16);
+    /// assert_eq!((-16).next_multiple_of(& 8), -16);
+    /// assert_eq!((-23).next_multiple_of(& 8), -16);
+    /// assert_eq!((-16).next_multiple_of(&-8), -16);
+    /// assert_eq!((-23).next_multiple_of(&-8), -24);
     /// ~~~
     #[inline]
     fn next_multiple_of(&self, other: &Self) -> Self where Self: Clone {
@@ -216,13 +220,17 @@ pub trait Integer: Sized + Num + PartialOrd + Ord + Eq {
     ///
     /// ~~~
     /// # use num_integer::Integer;
-    /// assert_eq!(16.next_multiple_back_of(& 8), 16);
-    /// assert_eq!(23.next_multiple_back_of(& 8), 16);
-    /// assert_eq!(16.next_multiple_back_of(&-8), 16);
-    /// assert_eq!(23.next_multiple_back_of(&-8), 24);
+    /// assert_eq!(( 16).prev_multiple_of(& 8),  16);
+    /// assert_eq!(( 23).prev_multiple_of(& 8),  16);
+    /// assert_eq!(( 16).prev_multiple_of(&-8),  16);
+    /// assert_eq!(( 23).prev_multiple_of(&-8),  24);
+    /// assert_eq!((-16).prev_multiple_of(& 8), -16);
+    /// assert_eq!((-23).prev_multiple_of(& 8), -24);
+    /// assert_eq!((-16).prev_multiple_of(&-8), -16);
+    /// assert_eq!((-23).prev_multiple_of(&-8), -16);
     /// ~~~
     #[inline]
-    fn next_multiple_back_of(&self, other: &Self) -> Self where Self: Clone {
+    fn prev_multiple_of(&self, other: &Self) -> Self where Self: Clone {
         self.clone() - self.mod_floor(other)
     }
 }