mv include/ruby/{impl,internal}

Devs do not love "impl".

1 files changed, 45 insertions, 0 deletions

diff --git a/include/ruby/internal/attr/nodiscard.h b/include/ruby/internal/attr/nodiscard.h
new file mode 100644
index 0000000000..ee3a1347df
--- /dev/null
+++ b/include/ruby/internal/attr/nodiscard.h
@@ -0,0 +1,45 @@
+#ifndef RBIMPL_ATTR_NODISCARD_H                      /*-*-C++-*-vi:se ft=cpp:*/
+#define RBIMPL_ATTR_NODISCARD_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      Defines #RBIMPL_ATTR_NODISCARD.
+ */
+#include "ruby/impl/has/attribute.h"
+#include "ruby/impl/has/c_attribute.h"
+#include "ruby/impl/has/cpp_attribute.h"
+
+/**
+ * Wraps  (or simulates)  `[[nodiscard]]`.  In  C++  (at least  since C++20)  a
+ * nodiscard attribute can  have a message why the result  shall not be ignoed.
+ * However GCC attribute and SAL annotation cannot take them.
+ */
+#if RBIMPL_HAS_CPP_ATTRIBUTE(nodiscard)
+# define RBIMPL_ATTR_NODISCARD() [[nodiscard]]
+#elif RBIMPL_HAS_C_ATTRIBUTE(nodiscard)
+# define RBIMPL_ATTR_NODISCARD() [[nodiscard]]
+#elif RBIMPL_HAS_ATTRIBUTE(warn_unused_result)
+# define RBIMPL_ATTR_NODISCARD() __attribute__((__warn_unused_result__))
+#elif defined(_Check_return_)
+# /* Take SAL definition. */
+# define RBIMPL_ATTR_NODISCARD() _Check_return_
+#else
+# define RBIMPL_ATTR_NODISCARD() /* void */
+#endif
+
+#endif /* RBIMPL_ATTR_NODISCARD_H */