title: Initializing a vector class member in C++
body: <p>I'm trying to set length and initialize a <code>vector</code> member of a class, but it seems it's only possible if initializing line is out of class.</p>
  <pre><code>//a vector, out of class set size to 5. initialized each value to Zero
  vector&lt;double&gt; vec(5,0.0f);//its ok
  
  class Bird{
  
  public:
      int id;
      //attempt to init is not possible if a vector a class of member
      vector&lt;double&gt; vec_(5, 0.0f);//error: expected a type specifier
  }
  </code></pre>
  <p>How can I do this inside the class?</p>