title: CGPoint property used in class from other class with Lvalue error
body: <p>I have two major classes in objective C using cocos2D, DebugZoneLayer and HeroClass.  Using Cocos2D may not be part of the issue.</p>
  
  <p>HeroClass contains a CGPoint and a property.  I have an instance of HeroClass in DebugZoneLayer initialized like <strong>hero = [[HeroClass alloc] init];</strong></p>
  
  <p>My HeroClass.h shortened to show you how I create a CGPoint vel.</p>
  
  <pre><code>@interface HeroClass : CCLayer {
      @public CGPoint _vel;
  }
  
  @property(assign) CGPoint vel;
  </code></pre>
  
  <p>In HeroClass.m I synthesize my property like <strong>@synthesize vel = _vel;</strong></p>
  
  <p>In DebugZoneLayer.m, I can reference my hero.vel x or y just fine, but anything that assigns a value to hero.vel x or y returns the error: <em>Lvalue required as left operand of assignment</em></p>