title: Are includes in a .h of a DLL exported? And should they?
body: <p>I have a huge c++ project in which several different units are built as DLL libraries. Now I have a library that is basic and shall be consumed by most of the other projects.</p>
  
  <p>So lets say the DLL.h file has something like:<br>
  <code>#include &lt;vector&gt;</code><br>
  <code>#include "OtherClass.h"</code></p>
  
  <p>I added the .lib path etc..., so my other project can use the DLL. In fact I have no errors on including the DLL on my "main" project.</p>
  
  <p>Now my question is the  include is that included in my main project when I do #include "DLL.h"?
  My rational being that since I will use vector in almost 100% of the projects that consume this DLL, I might as well push the include to it and not have one in every single project that uses it. (not sure if this is a best or worst practice).<br>
  The problem right now is my main project does recognize the types in OtherClass.h but not the type vector. Might this be because I don't explicitly use vector in the DLL and just did the include?</p>