Merge pull request #77 from hrosiak/layers_cm

layers adding

structures.cpp

@@ -67,6 +67,12 @@ void Layers::add(Material m){
     materials.push_back(m);
 }
 
+void Layers::add(const Layers& l){
+    for(auto m: l.get_materials()){
+      add(m);
+    }
+}
+
 double Layers::thickness() const {
     double sum = 0;
     for(auto &m : materials){

structures.h

@@ -274,6 +274,12 @@ namespace catima{
           */
         void add(Material m);
 
+	/**
+	 * append Layers
+	 * @para, l Layers
+	 */ 
+	void add(const Layers& l);
+
         /**
           * @return number of stored Materials
           */