Improved Integer class

- made "getValue" method const

source/boxing/Integer.cpp

@@ -257,6 +257,6 @@ std::string ls_std::Integer::toString()
   return std::to_string(this->value);
 }
 
-int ls_std::Integer::getValue() {
+int ls_std::Integer::getValue() const {
   return this->value;
 }

source/boxing/Integer.hpp

@@ -107,7 +107,7 @@ namespace ls_std {
 
       // additional functionality
 
-      int getValue();
+      int getValue() const;
 
     private: