title: mysql++ (mysqlpp): how to get number of rows in result prior to iteration using fetch_row through UseQueryResult
body: <p>Is there an API call provided by mysql++ to get the number of rows returned by the result?</p>
  
  <p>I have code structured as follows:</p>
  
  <pre><code>// ...
  Query q = conn.query(queryString);
  if(mysqlpp::UseQueryResult res = query.use()){
      // some code
  
     while(mysqlpp::Row row = res.fetch_row()){
  
  
     }
  }
  </code></pre>
  
  <p>My previous question <a href="https://stackoverflow.com/questions/22077283/allocate-more-memory-to-void-on-iteration-and-then-add-the-value">here</a> will be solved easily if a function that returns the number of rows of the result. I can use it to allocate memory of that size and fill in as I iterate row by row.</p>