migrate cmpmore into riff

libs/riff/src/binary_search.rs

@@ -3,7 +3,7 @@ use std::cmp::Ordering::Equal;
 use std::cmp::Ordering::Greater;
 use std::cmp::Ordering::Less;
 
-/// Method versions of functions.
+/// `{lower,upper}_bound`, etc
 pub trait BinarySearch<T> {
     fn partition_point<F: FnMut(&T) -> bool>(&self, pred: F) -> usize;
     fn lower_bound_by<F: FnMut(&T) -> Ordering>(&self, mut f: F) -> usize {

libs/riff/src/change_min_max.rs

@@ -0,0 +1,16 @@
+/// `change_min` and `change_max`
+pub trait ChangeMinMax: PartialOrd + Sized {
+    fn change_min(&mut self, rhs: Self) {
+        if *self > rhs {
+            *self = rhs
+        }
+    }
+
+    fn change_max(&mut self, rhs: Self) {
+        if *self < rhs {
+            *self = rhs
+        }
+    }
+}
+
+impl<T: PartialOrd + Sized> ChangeMinMax for T {}

libs/riff/src/lib.rs

@@ -1,7 +1,9 @@
 //! Future and otherworldly Rust features.
 
 mod binary_search;
+mod change_min_max;
 mod pop_if;
 
 pub use binary_search::BinarySearch;
+pub use change_min_max::ChangeMinMax;
 pub use pop_if::PopIf;

libs/riff/src/pop_if.rs

@@ -1,21 +1,6 @@
 use std::collections::BinaryHeap;
 
-/// Removes and returns the "top" element in a vector if the predicate
-/// returns `true`, or [`None`] if the predicate returns false or the container
-/// is empty.
-///
-/// # Examples
-///
-/// ```
-/// use riff::PopIf;
-///
-/// let mut vec = vec![1, 2, 3, 4];
-/// let pred = |x: &mut i32| *x % 2 == 0;
-///
-/// assert_eq!(vec.pop_if(pred), Some(4));
-/// assert_eq!(vec, [1, 2, 3]);
-/// assert_eq!(vec.pop_if(pred), None);
-/// ```
+/// Conditional `pop` function.
 pub trait PopIf {
     type Value;