title: c++ implementing friend/inline functions
body: <p>I can't seem to find the answer to this newbie question. If I have a class
  // Header file (.h)</p>
  
  <pre><code>Class X {
  public:
    friend bool operator==(const X&amp;, const X&amp;);
    inline size_type rows() const;
  };
  </code></pre>
  
  <p>etc...
  when I go to implement the .cpp file of X, should I include the words inline &amp; friend in the function names in the .cpp file. ie, should I implement my file similar to the below</p>
  
  <pre><code>// CPP file (.cpp)
  #include "X.h"
  friend bool operator==(const X&amp;, const X&amp;) {
    //implementation goes here
    //return true/false
  }
  
  inline size_type rows() const {
    return r;
  }
  </code></pre>
  
  <p>or should I not include these i.e. like below</p>
  
  <pre><code>#include "X.h"
  bool operator==(const X&amp;, const X&amp;) { ... }
  
  size_type rows() const { ... }
  </code></pre>