title: How to reuse C++ classes from one project to another without copying
body: <p>I am facing the following problem:</p>
  
  <p>I have a project which contains math classes (.h and .cpp files).
  I want to use these classes in a different project (not int he same solution) but I can't. </p>
  
  <p>In the new project I add a path to the include files of my math project. When I try to #include them it works and I can see my classes but upon trying to use them I get "Unresolved external". I haven't created a .dll or a .lib so I really don't know what's causing this.</p>
  
  <p>If you have any suggestions, I`ll appreciate it. </p>
  
  <p>Thank you very much in advance.</p>