title: C++ - initializing variables in header vs with constructor
body: <p>Regarding the following, are there any reasons to do one over the other or are they roughly equivalent?</p>
  
  <pre><code>class Something
  {
      int m_a = 0;
  };
  </code></pre>
  
  <p>vs</p>
  
  <pre><code>class Something
  {
      int m_a;
      Something(int p_a);
  };
  
  Something::Something(int p_a):m_a(p_a){ ... };
  </code></pre>