message: Replace forcing private functions to be deleted
diff: #endif
  #define ringmesh_disable_copy( Class ) \
  - private: \
  - Class( const Class & ) ; \
  - Class& operator=( const Class& )
  + public: \
  + Class( const Class & ) = delete ; \
  + Class& operator=( const Class& ) = delete
  // To avoid unused argument warning in function definition
  template< typename T > inline void ringmesh_unused( T const& )
  