LeMP macro to expand the C# `using` statement

expand_using.ecs - not .cs

// Define a macro recognized by LeMP ( http://ecsharp.net/lemp )
define #using($type $varname = $expression, $block) {
  {
    $type $varname = $expression;
    try $block
    finally {
      if ($varname != null)
        ((IDisposable)$varname).Dispose();
    }
  }
}

// This will be expanded
using (Font font1 = new Font("Arial",10f)) {
  byte charset = font1.GdiCharSet;
}