diff --git a/structures.cpp b/structures.cpp
index 3d4ed8e..3983a3b 100644
--- a/structures.cpp
+++ b/structures.cpp
@@ -62,16 +62,6 @@ void Material::calculate(){
     }
 }
 
-
-Layers& Layers::operator=(const Layers& other){
-    
-    materials.clear();
-    for(auto&e : other.get_materials()){
-        materials.push_back(e);
-    }
-    return *this;
-}
-
 void Layers::add(Material m){
     materials.push_back(m);
 }
@@ -81,7 +71,7 @@ Layers operator+(const Layers &a, const Layers&b){
     for(auto &e:a.materials){
         res.add(e);
     }
-    
+
     for(auto &e:b.materials){
         res.add(e);
     }
diff --git a/structures.h b/structures.h
index 154911c..b0f1950 100644
--- a/structures.h
+++ b/structures.h
@@ -44,7 +44,7 @@ namespace catima{
     };
 
     bool operator==(const Projectile &a, const Projectile&b);
-    
+
     /**
       * Target class is used to store constituents of the Material class
       * its just to hold A,Z data for individual atoms.
@@ -58,7 +58,7 @@ namespace catima{
     /**
      * Material
      * class to store Material information
-     * This class defines the material with which projectile will interact. 
+     * This class defines the material with which projectile will interact.
      * The class store nuclei constituents, density, thickness etc.
      */
     class Material{
@@ -92,20 +92,20 @@ namespace catima{
               * \endcode
               */
             Material(std::initializer_list<std::array<double,3>>list,double _density=0.0, double ipot = 0.0, double mass=0.0);
-            
+
             /**
              * calculates internal variables if needed
              */
             void calculate();
-            
+
             /**
-             * add atom with mass number _a and proton number _z to the Material 
+             * add atom with mass number _a and proton number _z to the Material
              * @param _a - mass number of the atom, is 0 the atomic weight of element _z is taken
              * @param _z - proton number of the atom
              * @param _stn - stoichiomatric number
              */
             void add_element(double _a, int _z, double _stn);
-            
+
             /**
              * returns i-th element of the Material as a std::pair of Target and corresponding stoichiometric number
              * @param i - index of element to return
@@ -139,7 +139,7 @@ namespace catima{
               * sets molar mass of the Material
               */
             Material& M(double mass){molar_mass=mass; return *this;}
-            
+
             /**
               * @return returns density in g/cm^3
               */
@@ -149,7 +149,7 @@ namespace catima{
               * sets density in g/cm^3
               */
             Material& density(double val){rho = val;return *this;};
-            
+
             /**
               * @return returns thickness in g/cm^2
               */
@@ -169,7 +169,7 @@ namespace catima{
               * set the mean ionization potential, if non elemental I should be used
               */
             Material& I(double val){i_potential = val;return *this;};
-            
+
             /**
               * 0 if default elemental potential is used
               * @return returns ionisation potential in ev
@@ -187,7 +187,7 @@ namespace catima{
               * return number density of atoms of i-th element in 10^23 units
               */
             double number_density(int i)const{
-              if(i>=atoms.size())return 0.0;  
+              if(i>=atoms.size())return 0.0;
               return number_density()*molar_fraction(i);
             }
 
@@ -227,14 +227,14 @@ namespace catima{
         double sigma_E=0.0;
         double sigma_a=0.0;
         double sigma_r=0.0;
-        double tof=0.0;   
+        double tof=0.0;
         #ifdef REACTIONS
         double sp = 1.0;
         #endif
     };
 
     /**
-      * structure to store results for calculation for multiple layers of materials, ie in catima::Layers 
+      * structure to store results for calculation for multiple layers of materials, ie in catima::Layers
       */
     struct MultiResult{
         std::vector<Result> results;
@@ -247,12 +247,11 @@ namespace catima{
      * class to store multiple material layers
      */
 
-    class Layers{        
+    class Layers{
         private:
         std::vector<Material> materials;
         public:
-        Layers(){};
-        Layers& operator=(const Layers& other);
+        Layers() = default;
 
         /**
           * @return reference to the std::vector of stored Materials
@@ -261,7 +260,7 @@ namespace catima{
 
         /**
           * add Material m to the Layers
-          * @param m Material 
+          * @param m Material
           */
         void add(Material m);
 
@@ -269,11 +268,11 @@ namespace catima{
           * @return number of stored Materials
           */
         int num()const{return materials.size();};
-        
+
         Material& operator[](int i){return materials[i];}
 
         friend Layers operator+(const Layers &a, const Layers&b);
-        
+
         friend Layers operator+(const Layers &a, const Material&b);
     };
 }
diff --git a/tests/test_structures.cpp b/tests/test_structures.cpp
index 5d99403..71740ad 100644
--- a/tests/test_structures.cpp
+++ b/tests/test_structures.cpp
@@ -7,31 +7,20 @@ using namespace std;
 #include "catima/catima.h"
 #include "catima/material_database.h"
 
-bool rcompare(double a, double b,double eps){
-    if(fabs((a-b)/fabs(b))<eps){
-      return true;
-    }
-    else{
-      std::cout<<"\033[1;31m"<<a<<" == "<<b<<"\033[0m"<<std::endl;
-      return false;
-    }
-      
-}
-
     TEST_CASE("atima material basic tests"){
             catima::Material water({
                 {1,1,2},
                 {16,8,1}
                 });
-                
+
             catima::Material water2;
             water2.add_element(1,1,2);
             water2.add_element(16,8,1);
-                
+
             catima::Material graphite;
             graphite.add_element(12,6,1);
             graphite.density(1.8);
-            
+
             CHECK(graphite.ncomponents()==1);
             CHECK(water.ncomponents()==2);
 
@@ -39,13 +28,13 @@ bool rcompare(double a, double b,double eps){
             CHECK(water.ncomponents()==2);
             CHECK(water.M()==18);
             CHECK(water2.ncomponents()==2);
-            CHECK(water2.M()==18);    
-            CHECK(graphite.I()==0.0);  
-  
+            CHECK(water2.M()==18);
+            CHECK(graphite.I()==0.0);
+
             graphite.add_element(18,40,1);
             CHECK(graphite.ncomponents()==2);
-            CHECK_FALSE(graphite.M()==approx(12,0.1));      
-            
+            CHECK_FALSE(graphite.M()==approx(12,0.1));
+
             CHECK(water==water2);
             CHECK(!(water==graphite));
             water.density(1.0);
@@ -84,7 +73,7 @@ bool rcompare(double a, double b,double eps){
         water2.add_element(1,1,2);
         water2.add_element(16,8,1);
         water2.density(1.0).thickness(2.0);
-                
+
         catima::Material graphite;
         graphite.add_element(12,6,1);
         graphite.density(1.8).thickness(1.0);
@@ -119,7 +108,7 @@ bool rcompare(double a, double b,double eps){
 
         catima::Layers focal_material = detector1 + detector2;
         CHECK(focal_material.num() == 8);
-    
+
     }
     TEST_CASE("basic projectile tests"){
       catima::Projectile p{12,6,6,1000};
@@ -127,7 +116,7 @@ bool rcompare(double a, double b,double eps){
       CHECK(p.Z==6);
       CHECK(p.Q==6);
       CHECK(p.T==1000);
-      
+
       catima::Projectile p2(12,6);
       CHECK(p.A==12);
       CHECK(p2.Z==6);
@@ -139,7 +128,7 @@ bool rcompare(double a, double b,double eps){
       CHECK(p2.T==500);
 
       catima::Projectile p3(12,6,5);
-      
+
       CHECK(p==p2);
       CHECK( !(p==p3));
     }
@@ -153,12 +142,12 @@ bool rcompare(double a, double b,double eps){
       CHECK(c1==c2);
       CHECK( !(c1==c3));
       CHECK(c1==c4);
-      
+
       c4.z_effective = catima::z_eff_type::global;
       CHECK(!(c1==c4));
       auto c5 = c4;
       CHECK(c4==c5);
-      
+
       c4.z_effective = catima::z_eff_type::hubert;
       CHECK(!(c4==c5) );
       CHECK(!(c4==c1));
@@ -184,7 +173,7 @@ bool rcompare(double a, double b,double eps){
         CHECK(mat5.get_element(0).Z==6);
         CHECK(mat5.get_element(1).A==16.0);
         CHECK(mat5.get_element(1).stn==2);
-        
+
         catima::Material mat6;
         mat6 = mat5;
         CHECK(mat5==mat6);
@@ -194,8 +183,8 @@ bool rcompare(double a, double b,double eps){
         CHECK(mat5.get_element(1).A==mat6.get_element(1).A);
         mat5.add_element(12,6,1);
         CHECK(mat5.ncomponents()==mat6.ncomponents()+1);
-        
-        // constructor with custom Ipot 
+
+        // constructor with custom Ipot
         catima::Material water1({
                 {1,1,2},
                 {16,8,1}
@@ -207,10 +196,10 @@ bool rcompare(double a, double b,double eps){
         CHECK(water1.ncomponents()==2);
         CHECK(water2.ncomponents()==2);
         CHECK(water1.density()==1.0);
-        CHECK(water2.density()==1.0); 
-        CHECK(water1.I()==0.0); 
-        CHECK(water2.I()==78.0); 
-        CHECK_FALSE(water1==water2); 
+        CHECK(water2.density()==1.0);
+        CHECK(water1.I()==0.0);
+        CHECK(water2.I()==78.0);
+        CHECK_FALSE(water1==water2);
 
     }
     TEST_CASE("fraction vs stn init"){
@@ -286,7 +275,7 @@ bool rcompare(double a, double b,double eps){
         c.thickness_cm(2.0);
         CHECK(c.number_density()==approx(1.7662,0.01));
         CHECK(c.number_density_cm2()==approx(2.0*1.7662,0.01));
-        
+
         water.thickness_cm(1.0);
         CHECK(water.number_density()==approx(0.3336,0.001));
         CHECK(water.number_density_cm2()==approx(0.3336,0.001));
@@ -296,7 +285,7 @@ bool rcompare(double a, double b,double eps){
         CHECK(water.number_density_cm2(1)==approx(0.3336,0.001));
         water.thickness_cm(3.0);
         CHECK(water.number_density_cm2()==approx(3.0*0.3336,0.001));
-    
+
         air.thickness_cm(1.0);
         CHECK(air.number_density(0)==approx(air.molar_fraction(0)*2*0.0002504,0.00001));
         CHECK(air.number_density(1)==approx(air.molar_fraction(1)*2*0.0002504,0.00001));