title: Initialization of a struct instance data member in constructor?
body: <p>I have a c++ class which as a private data member has a struct defined:</p>
  
  <pre><code>Class example {
  
  ...
  
  private:
     struct Impl;
     Impl&amp; structure_;
  };
  </code></pre>
  
  <p>Assuming that the struct Impl is defined as follows:</p>
  
  <pre><code>struct example::Impl{
      int m1;
      int m2;
      int m3;
  };
  </code></pre>
  
  <p>how would I be able to initialize the struct instance ( structure_ ) in the class's constructor?</p>
  
  <p>Right now I have:</p>
  
  <pre><code>example::example() :
       structure_ .m1(00),
       structure_ .m2(00),
       structure_ .m3(00) {
  ...
  }
  </code></pre>
  
  <p>.. for the initialization list, but I'm getting this error:</p>
  
  <blockquote>
    <p>'example::structure_' : must be initialized in constructor base/member initializer list</p>
  </blockquote>
  
  <p>how would I fix this?</p>
  
  <p>Thanks</p>