title: Problem With Macros (#define) "showing Expected identifier before numeric constant" error, in iPad
body: <p>I am developing an application where i need to define several constants that will be used in more than one class.I have defined all my constants in one .h file(say "constants.h") and imported that file in myAppName_Prefix.pch file located in "Other sources" folder of the project.The classes using these constants are being compiled with out any error but other classes, where i declared some UISwipeGestureRecognizers, are throwing error as"<strong>Expected identifier before numeric constant</strong>"
  this is the snippet of code from one of the classes that is showing error:</p>
  
  <pre><code>if (gesture.direction==UISwipeGestureRecognizerDirectionLeft)
  </code></pre>
  
  <p>i defined my constants as:</p>
  
  <pre><code>#define heading 1
  #define direction 2
  #define statement 3
  #define refLink 4
  #define correctResponse 5
  #define incorrect1Response 6
  </code></pre>
  
  <p>if i define them in each class individually then everything as working fine.
  Can any one please suggest me a way how to solve this issue.  </p>