Just check if an object is a Vector instance or not.

isVector.as

package rinaldi.util {
	
	import flash.utils.getQualifiedClassName;
	
	
	/**
	 * 
	 * Just check if an object is a Vector instance or not.
	 * 
	 * @param					p_object					Object to be checked.
	 * @return												Returns "true" if it's a vector instance, "false" otherwise.
	 * 
	 * @example
	 * <pre>
	 * import rinaldi.util.isVector;
	 * 
	 * trace(isVector(new Vector.<*>)); // true
	 * trace(isVector(new Array)); // false
	 * </pre>
	 * 
	 * @author Rafael Rinaldi (rafaelrinaldi.com)
	 * 
	 */
	 
	public function isVector( p_object : Object ) : Boolean {
		return getQualifiedClassName(p_object).split("__AS3__.vec::Vector").length > 1;
	}
}