Laravel4，检查一个orm模型是否有关系

I have many-to-many relationship between users and user roles, i want to check if an user has the given role like

if ($user->belongs($role->id)) doSomething();

but i can't find it in the docs.

Is there such a shortcut to check if a given model has a relationship, or a native L4 method?

This should work for you mate

 //get the attached roles of someuser
 $someusers_roles = $someuser->related()->lists('role_id');

 //check if he has a particular role attached
 if(in_array($particular_role->id, $someusers_roles))
 {
      doSomething();
 }

hope this helps you out.