title: C++ one or more multiply defined symbols found
body: <p>I have the following struct to manage Camera State with </p>
  
  <pre><code> struct keyState
   {
      float x_rotation, y_rotation, z_rotation;
      float x_rotation_rad, y_rotation_rad, z_rotation_rad;
      float x_pos, y_pos, z_pos;
   } state_manager;
  </code></pre>
  
  <p>This struct is located in my WalkingCameraManipulator.h class. WalkingCameraManipulator is implemented in WalkingCameraManipulator.cpp, and I have an #include "WalkingCameraManipulator" in my main class. </p>
  
  <p><strong>Error 1 error LNK2005: "struct keyState state_manager" (?state_manager@@3UkeyState@@A) already defined in main.obj
  Error   2   error LNK1169: one or more multiply defined symbols found</strong></p>
  
  <p>However, I am dealing with the following error message and need to find the best place for my struct. Any ideas on what I can do here? Thanks in advance.</p>