diff --git a/xs/src/libslic3r/ExPolygonCollection.hpp b/xs/src/libslic3r/ExPolygonCollection.hpp
index 1acd080a2..1d911f7e9 100644
--- a/xs/src/libslic3r/ExPolygonCollection.hpp
+++ b/xs/src/libslic3r/ExPolygonCollection.hpp
@@ -41,6 +41,14 @@ class ExPolygonCollection
     /// ExPolygons and check if at least one contains the point.
     bool contains(const Point &point) const;
 
+    size_t size() const { return expolygons.size(); }
+    ExPolygons::iterator begin() { return expolygons.begin(); }
+    ExPolygons::iterator end() { return expolygons.end(); }
+    ExPolygons::const_iterator cbegin() const { return expolygons.cbegin();}
+    ExPolygons::const_iterator cend() const { return expolygons.cend();}
+    ExPolygon& at(size_t i) { return expolygons.at(i); }
+    const ExPolygon& at(size_t i) const { return expolygons.at(i); }
+
 };
 
 inline ExPolygonCollection&
diff --git a/xs/src/libslic3r/ExtrusionEntityCollection.hpp b/xs/src/libslic3r/ExtrusionEntityCollection.hpp
index c3a26df82..4a710bc74 100644
--- a/xs/src/libslic3r/ExtrusionEntityCollection.hpp
+++ b/xs/src/libslic3r/ExtrusionEntityCollection.hpp
@@ -31,6 +31,7 @@ class ExtrusionEntityCollection : public ExtrusionEntity
         return this->entities.empty();
     };
     void clear();
+    size_t size() const { return this->entities.size(); }
     void swap (ExtrusionEntityCollection &c);
     void append(const ExtrusionEntity &entity);
     void append(const ExtrusionEntitiesPtr &entities);
@@ -53,6 +54,12 @@ class ExtrusionEntityCollection : public ExtrusionEntity
         CONFESS("Calling as_polyline() on a ExtrusionEntityCollection");
         return Polyline();
     };
+    ExtrusionEntitiesPtr::iterator begin() { return entities.begin(); }
+    ExtrusionEntitiesPtr::iterator end() { return entities.end(); }
+    ExtrusionEntitiesPtr::const_iterator cbegin() const { return entities.cbegin(); }
+    ExtrusionEntitiesPtr::const_iterator cend() const { return entities.cend(); }
+
+    
 };
 
 }