Make use of assignment operators

zcash_history/examples/long.rs

@@ -34,8 +34,8 @@ fn prepare_tree(vec: &Vec<NodeData>) -> Tree {
     loop {
         if peak_pos > vec.len() {
             // left child, -2^h
-            peak_pos = peak_pos - (1 << h);
-            h = h - 1;
+            peak_pos -= 1 << h;
+            h -= 1;
         }
 
         if peak_pos <= vec.len() {
@@ -62,7 +62,7 @@ fn prepare_tree(vec: &Vec<NodeData>) -> Tree {
     while h > 0 {
         let left_pos = peak_pos - (1 << h);
         let right_pos = peak_pos - 1;
-        h = h - 1;
+        h -= 1;
 
         // drafting left child
         draft(&mut extra, vec, left_pos, h);

zcash_history/src/tree.rs

@@ -209,7 +209,7 @@ impl Tree {
 
     fn pop(&mut self) {
         self.stored.remove(&(self.stored_count - 1));
-        self.stored_count = self.stored_count - 1;
+        self.stored_count -= 1;
     }
 
     /// Truncate one leaf from the end of the tree.

zcash_primitives/src/redjubjub.rs

@@ -184,7 +184,7 @@ pub fn batch_verify<'a, R: RngCore>(
         s.mul_assign(&z);
         s = s.neg();
 
-        r = r * z;
+        r *= z;
 
         c.mul_assign(&z);