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author | 卜部昌平 <shyouhei@ruby-lang.org> | 2020-04-08 13:28:13 +0900 |
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committer | GitHub <noreply@github.com> | 2020-04-08 13:28:13 +0900 |
commit | 9e6e39c3512f7a962c44dc3729c98a0f8be90341 (patch) | |
tree | 901a22676d54d78240e450b64a8cd06eb1703910 /include/ruby/3/arithmetic/fixnum.h | |
parent | 5ac4bf2cd87e1eb5779ca5ae7f96a1a22e8436d9 (diff) |
Merge pull request #2991 from shyouhei/ruby.h
Split ruby.h
Notes
Notes:
Merged-By: shyouhei <shyouhei@ruby-lang.org>
Diffstat (limited to 'include/ruby/3/arithmetic/fixnum.h')
-rw-r--r-- | include/ruby/3/arithmetic/fixnum.h | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/include/ruby/3/arithmetic/fixnum.h b/include/ruby/3/arithmetic/fixnum.h new file mode 100644 index 0000000000..e995b5f3f8 --- /dev/null +++ b/include/ruby/3/arithmetic/fixnum.h @@ -0,0 +1,44 @@ +/** \noop-*-C++-*-vi:ft=cpp + * @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 `RUBY3` or `ruby3` 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. + */ +#ifndef RUBY3_ARITHMETIC_FIXNUM_H +#define RUBY3_ARITHMETIC_FIXNUM_H +#include "ruby/backward/2/limits.h" + +#define FIXABLE RB_FIXABLE +#define FIXNUM_MAX RUBY_FIXNUM_MAX +#define FIXNUM_MIN RUBY_FIXNUM_MIN +#define NEGFIXABLE RB_NEGFIXABLE +#define POSFIXABLE RB_POSFIXABLE + +/* + * 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-stragne "< FIXNUM_MAX + 1" expression below is due to this. + */ +#define RB_POSFIXABLE(_) ((_) < RUBY_FIXNUM_MAX + 1) +#define RB_NEGFIXABLE(_) ((_) >= RUBY_FIXNUM_MIN) +#define RB_FIXABLE(_) (RB_POSFIXABLE(_) && RB_NEGFIXABLE(_)) +#define RUBY_FIXNUM_MAX (LONG_MAX / 2) +#define RUBY_FIXNUM_MIN (LONG_MIN / 2) + +#endif /* RUBY3_ARITHMETIC_FIXNUM_H */ |