Current File : //opt/alt/ruby31/include/ruby/internal/core/rclass.h
#ifndef RBIMPL_RCLASS_H /*-*-C++-*-vi:se ft=cpp:*/
#define RBIMPL_RCLASS_H
/**
* @file
* @author Ruby developers <ruby-core@ruby-lang.org>
* @copyright This file is a part of the programming language Ruby.
* Permission is hereby granted, to either redistribute and/or
* modify this file, provided that the conditions mentioned in the
* file COPYING are met. Consult the file for details.
* @warning Symbols prefixed with either `RBIMPL` or `rbimpl` are
* implementation details. Don't take them as canon. They could
* rapidly appear then vanish. The name (path) of this header file
* is also an implementation detail. Do not expect it to persist
* at the place it is now. Developers are free to move it anywhere
* anytime at will.
* @note To ruby-core: remember that this header can be possibly
* recursively included from extension libraries written in C++.
* Do not expect for instance `__VA_ARGS__` is always available.
* We assume C99 for ruby itself but we don't assume languages of
* extension libraries. They could be written in C++98.
* @brief Routines to manipulate struct RClass.
* @note The struct RClass itself is opaque.
*/
#include "ruby/internal/dllexport.h"
#include "ruby/internal/value.h"
#include "ruby/internal/cast.h"
/** @cond INTERNAL_MACRO */
#define RMODULE_IS_OVERLAID RMODULE_IS_OVERLAID
#define RMODULE_IS_REFINEMENT RMODULE_IS_REFINEMENT
#define RMODULE_INCLUDED_INTO_REFINEMENT RMODULE_INCLUDED_INTO_REFINEMENT
/** @endcond */
/**
* Convenient casting macro.
*
* @param obj An object, which is in fact an RClass.
* @return The passed object casted to RClass.
*/
#define RCLASS(obj) RBIMPL_CAST((struct RClass *)(obj))
/** @alias{RCLASS} */
#define RMODULE RCLASS
/** @alias{rb_class_get_superclass} */
#define RCLASS_SUPER rb_class_get_superclass
/**
* @private
*
* Bits that you can set to ::RBasic::flags.
*
* @internal
*
* Why is it here, given RClass itself is not?
*/
enum ruby_rmodule_flags {
/**
* This flag has something to do with refinements... I guess? It is set on
* occasions for modules that are refined by refinements, but it seems
* ... nobody cares about such things? Not sure but this flag could
* perhaps be a write-only information.
*/
RMODULE_IS_OVERLAID = RUBY_FL_USER2,
/**
* This flag has something to do with refinements. A module created using
* rb_mod_refine() has this flag set. This is the bit which controls
* difference between normal inclusion versus refinements.
*/
RMODULE_IS_REFINEMENT = RUBY_FL_USER3,
/**
* This flag has something to do with refinements. This is set when a
* (non-refinement) module is included into another module, which is a
* refinement. This amends the way `super` searches for a super method.
*
* ```ruby
* class Foo
* def foo
* "Foo"
* end
* end
*
* module Bar
* def foo
* "[#{super}]" # this
* end
* end
*
* module Baz
* refine Foo do
* include Bar
* def foo
* "<#{super}>"
* end
* end
* end
*
* using Baz
* Foo.new.foo # => "[<Foo>]"
* ```
*
* The `super` marked with "this" comment shall look for overlaid
* `Foo#foo`, which is not the ordinal method lookup direction.
*/
RMODULE_INCLUDED_INTO_REFINEMENT = RUBY_FL_USER4
};
struct RClass; /* Opaque, declared here for RCLASS() macro. */
RBIMPL_SYMBOL_EXPORT_BEGIN()
/**
* Returns the superclass of a class.
* @param[in] klass An object of RClass.
* @retval RUBY_Qfalse `klass` has no super class.
* @retval otherwise Raw superclass of `klass`
* @see rb_class_superclass
*
* ### Q&A ###
*
* - Q: How can a class have no super class?
*
* - A: `klass` could be a module. Or it could be ::rb_cBasicObject.
*
* - Q: What do you mean by "raw" superclass?
*
* - A: This is a really good question. The answer is that this function
* returns something different from what you would normally expect. On
* occasions ruby inserts hidden classes in a hierarchy of class
* inheritance behind-the-scene. Such classes are called "iclass"es and
* distinguished using ::RUBY_T_ICLASS in C level. They are truly
* transparent from Ruby level but can be accessed from C, by using this
* API.
*/
VALUE rb_class_get_superclass(VALUE klass);
RBIMPL_SYMBOL_EXPORT_END()
#endif /* RBIMPL_RCLASS_H */