1 files changed, 58 insertions, 0 deletions
diff --git a/include/ruby/impl/arithmetic/char.h b/include/ruby/impl/arithmetic/char.h
new file mode 100644
index 0000000000..03afa0a406
--- /dev/null
+++ b/include/ruby/impl/arithmetic/char.h
@@ -0,0 +1,58 @@
+#ifndef RUBY3_ARITHMETIC_CHAR_H                      /*-*-C++-*-vi:se ft=cpp:*/
+#define RUBY3_ARITHMETIC_CHAR_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  `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      Arithmetic conversion between C's `char` and Ruby's.
+ */
+#include "ruby/3/arithmetic/int.h"  /* NUM2INT is here, but */
+#include "ruby/3/arithmetic/long.h" /* INT2FIX is here.*/
+#include "ruby/3/attr/artificial.h"
+#include "ruby/3/attr/const.h"
+#include "ruby/3/attr/constexpr.h"
+#include "ruby/3/cast.h"
+#include "ruby/3/core/rstring.h"
+#include "ruby/3/value_type.h"
+
+#define RB_NUM2CHR rb_num2char_inline
+#define NUM2CHR    RB_NUM2CHR
+#define CHR2FIX    RB_CHR2FIX
+
+/** @cond INTERNAL_MACRO */
+#define RB_CHR2FIX RB_CHR2FIX
+/** @endcond */
+
+RUBY3_ATTR_CONST_ON_NDEBUG()
+RUBY3_ATTR_CONSTEXPR_ON_NDEBUG(CXX14)
+RUBY3_ATTR_ARTIFICIAL()
+static inline VALUE
+RB_CHR2FIX(unsigned char c)
+{
+    return RB_INT2FIX(c);
+}
+
+static inline char
+rb_num2char_inline(VALUE x)
+{
+    if (RB_TYPE_P(x, RUBY_T_STRING) && (RSTRING_LEN(x)>=1))
+        return RSTRING_PTR(x)[0];
+    else
+        return RUBY3_CAST((char)RB_NUM2INT(x));
+}
+
+#endif /* RUBY3_ARITHMETIC_CHAR_H */