#ifndef RBIMPL_ARITHMETIC_FIXNUM_H /*-*-C++-*-vi:se ft=cpp:*/
#define RBIMPL_ARITHMETIC_FIXNUM_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 Handling of integers formerly known as Fixnums.
*/
#include "ruby/backward/2/limits.h"
#define FIXABLE RB_FIXABLE /**< @old{RB_FIXABLE} */
#define FIXNUM_MAX RUBY_FIXNUM_MAX /**< @old{RUBY_FIXNUM_MAX} */
#define FIXNUM_MIN RUBY_FIXNUM_MIN /**< @old{RUBY_FIXNUM_MIN} */
#define NEGFIXABLE RB_NEGFIXABLE /**< @old{RB_NEGFIXABLE} */
#define POSFIXABLE RB_POSFIXABLE /**< @old{RB_POSFIXABLE} */
/**
* Checks if the passed value is in range of fixnum, assuming it is a positive
* number. Can sometimes be useful for C's unsigned integer types.
*
* @internal
*
* FIXABLE can be applied to anything, from double to intmax_t. The problem is
* double. On a 64bit system RUBY_FIXNUM_MAX is 4,611,686,018,427,387,903,
* which is not representable by a double. The nearest value that a double can
* represent is 4,611,686,018,427,387,904, which is not fixable. The
* seemingly-strange "< FIXNUM_MAX + 1" expression below is due to this.
*/
#define RB_POSFIXABLE(_) ((_) < RUBY_FIXNUM_MAX + 1)
/**
* Checks if the passed value is in range of fixnum, assuming it is a negative
* number. This is an implementation of #RB_FIXABLE. Rarely used stand alone.
*/
#define RB_NEGFIXABLE(_) ((_) >= RUBY_FIXNUM_MIN)
/** Checks if the passed value is in range of fixnum */
#define RB_FIXABLE(_) (RB_POSFIXABLE(_) && RB_NEGFIXABLE(_))
/** Maximum possible value that a fixnum can represent. */
#define RUBY_FIXNUM_MAX (LONG_MAX / 2)
/** Minimum possible value that a fixnum can represent. */
#define RUBY_FIXNUM_MIN (LONG_MIN / 2)
#endif /* RBIMPL_ARITHMETIC_FIXNUM_H */
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