Fixed some compilation warnings.

src/libslic3r/ExtrusionEntityCollection.hpp

@@ -106,7 +106,7 @@ public:
     double total_volume() const override { double volume=0.; for (const auto& ent : entities) volume+=ent->total_volume(); return volume; }
 
     // Following methods shall never be called on an ExtrusionEntityCollection.
-    Polyline as_polyline() const {
+    Polyline as_polyline() const override {
         throw std::runtime_error("Calling as_polyline() on a ExtrusionEntityCollection");
         return Polyline();
     };

src/libslic3r/GCode/ToolOrdering.hpp

@@ -30,14 +30,6 @@ public:
     // When allocating extruder overrides of an object's ExtrusionEntity, overrides for maximum 3 copies are allocated in place.
     typedef boost::container::small_vector<int32_t, 3> ExtruderPerCopy;
 
-    class ExtruderOverrides
-    {
-    public:
-    	ExtruderOverrides(const ExtruderPerCopy *overrides, const int correct_extruder_id) : m_overrides(overrides) {}
-    private:
-    	const ExtruderPerCopy *m_overrides;
-    };
-
     // This is called from GCode::process_layer - see implementation for further comments:
     const ExtruderPerCopy* get_extruder_overrides(const ExtrusionEntity* entity, int correct_extruder_id, size_t num_of_copies);
 

src/libslic3r/Print.hpp

@@ -349,7 +349,7 @@ public:
     Print() = default;
 	virtual ~Print() { this->clear(); }
 
-	PrinterTechnology	technology() const noexcept { return ptFFF; }
+	PrinterTechnology	technology() const noexcept override { return ptFFF; }
 
     // Methods, which change the state of Print / PrintObject / PrintRegion.
     // The following methods are synchronized with process() and export_gcode(),