title: Is it a good idea to always return references for member variable getters?
body: <p>If I have a class that has many <code>int</code>, <code>float</code>, and <code>enum</code> member variables, is it considered efficient and/or good practice to return them as references rather than copies, and return constant references where no changes should be made? Or is there a reason I should return them as copies?</p>