title: ignoring warning "-Wunused-result"
body: <p>I am new to c++.<p>
  I want to ignore warning <code>-Wunused-result</code> which I guess popped because of <code>-Wall</code> flag. <p> I did search on net and found that this is I can ignore it by declaring a <code>pragma</code>. I don't have much knowledge about <code>pragma</code> but it says that I have to write <code>warning number</code> in order to ignore it.<p> What is <code>warning number</code> of <code>-Wunused-result</code>, or <strong>is there any other way I can ignore or disable this specific warning?</strong></p>
  
  <p>code:- </p>
  
  <pre><code>freopen("input", "r", stdin);
  freopen("output", "a", stdout);
  </code></pre>
  
  <p>on compiling:-</p>
  
  <pre><code>warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result]
  </code></pre>
  
  <p>I found that I need to declare something like</p>
  
  <p><br><code>#pragma warning( disable : number_of_warning )</code></p>
  
  <p><p></p>