split include/ruby/encoding.h

2,291 lines are too much!  include/ruby/encoding.h became the biggest
header file once it had doxygen comments.  Let us split it into smaller
parts, so that we can better organise their contents.

include/ruby/internal/encoding/sprintf.h

@@ -0,0 +1,78 @@
+#ifndef RUBY_INTERNAL_ENCODING_SPRINTF_H             /*-*-C++-*-vi:se ft=cpp:*/
+#define RUBY_INTERNAL_ENCODING_SPRINTF_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      Routines to manipulate encodings of symbols.
+ */
+#include "ruby/internal/config.h"
+#include <stdarg.h>
+#include "ruby/internal/attr/format.h"
+#include "ruby/internal/attr/nonnull.h"
+#include "ruby/internal/attr/noreturn.h"
+#include "ruby/internal/dllexport.h"
+#include "ruby/internal/encoding/encoding.h"
+#include "ruby/internal/value.h"
+
+RBIMPL_SYMBOL_EXPORT_BEGIN()
+RBIMPL_ATTR_NONNULL((2))
+RBIMPL_ATTR_FORMAT(RBIMPL_PRINTF_FORMAT, 2, 3)
+/**
+ * Identical to  rb_sprintf(), except it  additionally takes an  encoding.  The
+ * passed encoding rules  both the incoming format specifier  and the resulting
+ * string.
+ *
+ * @param[in]  enc  Encoding of `fmt`.
+ * @param[in]  fmt  A `printf`-like format specifier.
+ * @param[in]  ...  Variadic number of contents to format.
+ * @return     A rendered new instance of ::rb_cString, of `enc` encoding.
+ */
+VALUE rb_enc_sprintf(rb_encoding *enc, const char *fmt, ...);
+
+RBIMPL_ATTR_NONNULL((2))
+RBIMPL_ATTR_FORMAT(RBIMPL_PRINTF_FORMAT, 2, 0)
+/**
+ * Identical  to  rb_enc_sprintf(), except  it  takes  a `va_list`  instead  of
+ * variadic  arguments.   It  can  also  be seen  as  a  routine  identical  to
+ * rb_vsprintf(), except it additionally takes an encoding.
+ *
+ * @param[in]  enc  Encoding of `fmt`.
+ * @param[in]  fmt  A `printf`-like format specifier.
+ * @param[in]  ap   Contents to format.
+ * @return     A rendered new instance of ::rb_cString, of `enc` encoding.
+ */
+VALUE rb_enc_vsprintf(rb_encoding *enc, const char *fmt, va_list ap);
+
+RBIMPL_ATTR_NORETURN()
+RBIMPL_ATTR_NONNULL((3))
+RBIMPL_ATTR_FORMAT(RBIMPL_PRINTF_FORMAT, 3, 4)
+/**
+ * Identical to rb_raise(), except it additionally takes an encoding.
+ *
+ * @param[in]  enc  Encoding of the generating exception.
+ * @param[in]  exc  A subclass of ::rb_eException.
+ * @param[in]  fmt  Format specifier string compatible with rb_sprintf().
+ * @param[in]  ...  Contents of the message.
+ * @exception  exc  The specified exception.
+ * @note       It never returns.
+ */
+void rb_enc_raise(rb_encoding *enc, VALUE exc, const char *fmt, ...);
+
+RBIMPL_SYMBOL_EXPORT_END()
+
+#endif /* RUBY_INTERNAL_ENCODING_SPRINTF_H */