title: Proper way to deal with LNK errors
body: <p>So I've been programming for a little while and I run into LNK errors all the time and just don't really know how to deal with them. Most often I get <code>Unresolved external symbol</code> or <code>'. . . ' was already defined in . obj</code>. This probably comes from how I include my header files. I have a header file and a matching cpp file and i include the header file anywhere where its needed. I dont know if thats ok to do. For example, I recently made a class with a static vector that I then included in several other . cpp files. Of course, I then immediately got an Unresolved external symbol error. Is there any proper way or rule to avoid these <code>LNK2005</code> and <code>LNK2019</code> mistakes.</p>