BOOL
Type to represent a Boolean value.
Category
An opaque type that represents a category.
Class
An opaque type that represents an Objective-C class.
Ivar
An opaque type that represents an instance variable.
Method
An opaque type that represents a method in a class definition.
NSInteger
Describes an integer.
NSUInteger
Describes an unsigned integer.
SEL
Defines an opaque type that represents a method selector.
objc_method_description
Defines an Objective-C method.
objc_property_t
An opaque type that represents an Objective-C declared property.
objc_super
Specifies the superclass of an instance.