From c92f6a5ad7ed58b48832bd49a38111e385bdf598 Mon Sep 17 00:00:00 2001
From: philipp <descpl@yahoo.de>
Date: Thu, 6 Feb 2020 23:52:52 +0100
Subject: [PATCH 1/2] Avoid redundant bookkeeping in `pool_len`

lazy_buffer gives `len` in via a field lookup (Vec::len), so I do not see why we should duplicate this compuation manually.
---
 src/combinations.rs | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/src/combinations.rs b/src/combinations.rs
index e8efb473f..291b326b9 100644
--- a/src/combinations.rs
+++ b/src/combinations.rs
@@ -51,8 +51,6 @@ impl<I> Iterator for Combinations<I>
 {
     type Item = Vec<I::Item>;
     fn next(&mut self) -> Option<Self::Item> {
-        let mut pool_len = self.pool.len();
-
         if self.first {
             if self.pool.is_done() {
                 return None;
@@ -65,13 +63,11 @@ impl<I> Iterator for Combinations<I>
             let mut i: usize = self.indices.len() - 1;
 
             // Check if we need to consume more from the iterator
-            if self.indices[i] == pool_len - 1 && !self.pool.is_done() {
-                if self.pool.get_next() {
-                    pool_len += 1;
-                }
+            if self.indices[i] == self.pool.len() - 1 && !self.pool.is_done() {
+                self.pool.get_next(); // may change pool size
             }
 
-            while self.indices[i] == i + pool_len - self.indices.len() {
+            while self.indices[i] == i + self.pool.len() - self.indices.len() {
                 if i > 0 {
                     i -= 1;
                 } else {

From 9e2715416ae52959447bec3f8b453023b1699a4e Mon Sep 17 00:00:00 2001
From: philipp <descpl@yahoo.de>
Date: Tue, 11 Feb 2020 22:27:21 +0100
Subject: [PATCH 2/2] Avoid redundant call to is_done

get_next does the same check internally.
---
 src/combinations.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/combinations.rs b/src/combinations.rs
index 291b326b9..875951808 100644
--- a/src/combinations.rs
+++ b/src/combinations.rs
@@ -63,7 +63,7 @@ impl<I> Iterator for Combinations<I>
             let mut i: usize = self.indices.len() - 1;
 
             // Check if we need to consume more from the iterator
-            if self.indices[i] == self.pool.len() - 1 && !self.pool.is_done() {
+            if self.indices[i] == self.pool.len() - 1 {
                 self.pool.get_next(); // may change pool size
             }