1 files changed, 6 insertions, 8 deletions
diff --git a/xs/src/libslic3r/Polyline.cpp b/xs/src/libslic3r/Polyline.cpp
index b2e50bca3..e0cd5221c 100644
--- a/xs/src/libslic3r/Polyline.cpp
+++ b/xs/src/libslic3r/Polyline.cpp
@@ -184,15 +184,13 @@ void Polyline::split_at(const Point &point, Polyline* p1, Polyline* p2) const
 
 bool Polyline::is_straight() const
 {
-    /*  Check that each segment's direction is equal to the line connecting
-        first point and last point. (Checking each line against the previous
-        one would cause the error to accumulate.) */
+    // Check that each segment's direction is equal to the line connecting
+    // first point and last point. (Checking each line against the previous
+    // one would cause the error to accumulate.)
     double dir = Line(this->first_point(), this->last_point()).direction();
-    
-    Lines lines = this->lines();
-    for (Lines::const_iterator line = lines.begin(); line != lines.end(); ++line) {
-        if (!line->parallel_to(dir)) return false;
-    }
+    for (const auto &line: this->lines())
+        if (! line.parallel_to(dir))
+            return false;
     return true;
 }