title: c++ expected primary expression before const error, in a simple header file
body: <p>In a header file, I want to declare a short function
  Rotate(array, degree), which would rotate an array of elements by some degree:</p>
  
  <p>for example, if my array contains {1, 2, 3, 4, 5}, and the rotation degree is 2, then the modified array should be {4, 5, 1, 2, 3}.</p>
  
  <p>My code is as follows: </p>
  
  <pre><code>#ifndef ROTATE_ARRAY_H
  #define ROTATE_ARRAY_H
  
  void Rotate(std::vector&lt;int&gt;&amp; array, const int rotation_degree);
  
  #endif  // ROTATE_ARRAY_H
  </code></pre>
  
  <p>Now this short header file gives "expected primary expression before const"
  on the line, where void is declared.</p>
  
  <p>Note that if I remove vector from the function argument list, then </p>
  
  <pre><code>void Rotate(const int rotation_degree);
  </code></pre>
  
  <p>compiles successfully (but of course does not work as expected). So I believe, the problem is something to do with the vector.</p>
  
  <p>Please bare in mind that this is a header file, and no code like</p>
  
  <pre><code>include&lt;vector&gt;; 
  using namespace std;
  </code></pre>
  
  <p>is allowed, as that would violate the style guide.</p>
  
  <p>So the question is: how to get rid of "expected primary expression before const" error?</p>
  
  <p>Thanks for your help in advance.</p>