title: Updating existing variable value inside #ifdef?
body: <p>I am new to C++, and I am trying to update a <code>BOOL</code> variable in the following block of code :</p>
  
  <pre class="lang-cpp prettyprint-override"><code>#define REMOVE_REPLACED_BY_SUCESSOR 1 
  
  bool rm_by_succ = 0;
  
  #ifdef REMOVE_REPLACED_BY_SUCESSOR
      rm_by_succ = 1;
  #endif
  </code></pre>
  
  <p>But my <em>g++</em> compiler gives me the following error :</p>
  
  <pre><code>‘rm_by_succ’ does not name a type
  </code></pre>
  
  <p>Could someone please explain to me what I did wrong ?</p>