#ifndef RBIMPL_INTERN_ENUM_H /*-*-C++-*-vi:se ft=cpp:*/
#define RBIMPL_INTERN_ENUM_H
/**
* @file
* @author Ruby developers <[email protected]>
* @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 Public APIs related to ::rb_mEnumerable.
*/
#include "ruby/internal/dllexport.h"
#include "ruby/internal/value.h"
RBIMPL_SYMBOL_EXPORT_BEGIN()
/* enum.c */
/**
* Basically identical to rb_ary_new_form_values(), except it returns something
* different when `argc` < 2.
*
* @param[in] argc Number of objects of `argv`.
* @param[in] argv Arbitrary objects.
* @retval RUBY_Qnil `argc` is zero.
* @retval argv[0] `argc` is one.
* @retval otherwise Otherwise.
*
* @internal
*
* What is this business? Well, this function is about `yield`'s taking
* multiple values. Consider following user-defined class:
*
* ```ruby
* class Foo
* include Enumerable
*
* def each
* yield :q, :w, :e, :r
* end
* end
*
* Foo.new.each_with_object([]) do |i, j|
* j << i # ^^^ <- What to expect for `i`?
* end
* ```
*
* Here, `Foo#each_with_object` is in fact `Enumerable#each_with_object`, which
* doesn't know what would be yielded. Yet, it has to take a block of arity 2.
* This function is used here, to "pack" arbitrary number of yielded objects
* into one.
*
* If people want to implement their own `Enumerable#each_with_object` this API
* can be handy. Though @shyouhei suspects it is relatively rare for 3rd party
* extension libraries to have such things. Also `Enumerable#each_entry` is
* basically this function exposed as a Ruby method.
*/
VALUE rb_enum_values_pack(int argc, const VALUE *argv);
RBIMPL_SYMBOL_EXPORT_END()
#endif /* RBIMPL_INTERN_ENUM_H */
