--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,15 @@
 2010-03-07  Bruno Haible  <bruno@clisp.org>
 
+	string: Avoid #define replacements in C++ mode.
+	* lib/string.in.h: Include c++defs.h.
+	(stpncpy): Define to rpl_stpncpy, not gnu_stpncpy.
+	(memchr, memmem, mempcpy, memrchr, rawmemchr, stpcpy, stpncpy,
+	strchrnul, strdup, strndup, strnlen, strpbrk, strsep, strstr,
+	strcasestr, strtok_r, mbslen, mbschr, mbsrchr, mbspbrk, strerror,
+	strsignal, strverscmp): In C++, define a namespaced alias symbol.
+	* modules/string (Depends-on): Add c++defs.
+	(Makefile.am): Update string.h rule.
+
 	stdlib: Avoid #define replacements in C++ mode.
 	* lib/stdlib.in.h: Include c++defs.h.
 	(atoll, calloc, canonicalize_file_name, getloadavg, getsubopt, malloc,

--- a/lib/string.in.h
+++ b/lib/string.in.h
@@ -48,23 +48,39 @@
 #endif
 
 
+/* The definitions of _GL_FUNCDECL_RPL etc. are copied here.  */
+
 /* The definition of _GL_ARG_NONNULL is copied here.  */
 
 /* The definition of _GL_WARN_ON_USE is copied here.  */
 
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-
 /* Return the first instance of C within N bytes of S, or NULL.  */
 #if @GNULIB_MEMCHR@
 # if @REPLACE_MEMCHR@
-#  define memchr rpl_memchr
-extern void *memchr (void const *__s, int __c, size_t __n)
-     __attribute__ ((__pure__)) _GL_ARG_NONNULL ((1));
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   define memchr rpl_memchr
+#  endif
+_GL_FUNCDECL_RPL (memchr, void *, (void const *__s, int __c, size_t __n)
+                                  __attribute__ ((__pure__))
+                                  _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (memchr, void *, (void const *__s, int __c, size_t __n));
+# else
+#  if defined __SUNPRO_CC
+  /* This compiler defines an overloaded function
+       extern "C" { const void * std::memchr (const void *, int, size_t); }
+       extern "C++" { inline void * std::memchr (void *, int, size_t); }
+     and diagnoses an error
+     "Error: Could not find a match for std::memchr(const void*, int, unsigned)"
+   */
+_GL_CXXALIAS_SYS_CAST2 (memchr,
+                        void *, (void const *__s, int __c, size_t __n),
+                        void const *, (void const *__s, int __c, size_t __n));
+#  else
+_GL_CXXALIAS_SYS (memchr, void *, (void const *__s, int __c, size_t __n));
+#  endif
 # endif
+_GL_CXXALIASWARN (memchr);
 #elif defined GNULIB_POSIXCHECK
 # undef memchr
 /* Assume memchr is always declared.  */
@@ -75,13 +91,28 @@
 /* Return the first occurrence of NEEDLE in HAYSTACK.  */
 #if @GNULIB_MEMMEM@
 # if @REPLACE_MEMMEM@
-#  define memmem rpl_memmem
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   define memmem rpl_memmem
+#  endif
+_GL_FUNCDECL_RPL (memmem, void *,
+                  (void const *__haystack, size_t __haystack_len,
+                   void const *__needle, size_t __needle_len)
+                  __attribute__ ((__pure__)) _GL_ARG_NONNULL ((1, 3)));
+_GL_CXXALIAS_RPL (memmem, void *,
+                  (void const *__haystack, size_t __haystack_len,
+                   void const *__needle, size_t __needle_len));
+# else
+#  if ! @HAVE_DECL_MEMMEM@
+_GL_FUNCDECL_SYS (memmem, void *,
+                  (void const *__haystack, size_t __haystack_len,
+                   void const *__needle, size_t __needle_len)
+                  __attribute__ ((__pure__)) _GL_ARG_NONNULL ((1, 3)));
+#  endif
+_GL_CXXALIAS_SYS (memmem, void *,
+                  (void const *__haystack, size_t __haystack_len,
+                   void const *__needle, size_t __needle_len));
 # endif
-# if ! @HAVE_DECL_MEMMEM@ || @REPLACE_MEMMEM@
-extern void *memmem (void const *__haystack, size_t __haystack_len,
-                     void const *__needle, size_t __needle_len)
-     __attribute__ ((__pure__)) _GL_ARG_NONNULL ((1, 3));
-# endif
+_GL_CXXALIASWARN (memmem);
 #elif defined GNULIB_POSIXCHECK
 # undef memmem
 # if HAVE_RAW_DECL_MEMMEM
@@ -95,10 +126,15 @@
    last written byte.  */
 #if @GNULIB_MEMPCPY@
 # if ! @HAVE_MEMPCPY@
-extern void *mempcpy (void *restrict __dest, void const *restrict __src,
-                      size_t __n)
-     _GL_ARG_NONNULL ((1, 2));
+_GL_FUNCDECL_SYS (mempcpy, void *,
+                  (void *restrict __dest, void const *restrict __src,
+                   size_t __n)
+                  _GL_ARG_NONNULL ((1, 2)));
 # endif
+_GL_CXXALIAS_SYS (mempcpy, void *,
+                  (void *restrict __dest, void const *restrict __src,
+                   size_t __n));
+_GL_CXXALIASWARN (mempcpy);
 #elif defined GNULIB_POSIXCHECK
 # undef mempcpy
 # if HAVE_RAW_DECL_MEMPCPY
@@ -110,9 +146,12 @@
 /* Search backwards through a block for a byte (specified as an int).  */
 #if @GNULIB_MEMRCHR@
 # if ! @HAVE_DECL_MEMRCHR@
-extern void *memrchr (void const *, int, size_t)
-     __attribute__ ((__pure__)) _GL_ARG_NONNULL ((1));
+_GL_FUNCDECL_SYS (memrchr, void *, (void const *, int, size_t)
+                                   __attribute__ ((__pure__))
+                                   _GL_ARG_NONNULL ((1)));
 # endif
+_GL_CXXALIAS_SYS (memrchr, void *, (void const *, int, size_t));
+_GL_CXXALIASWARN (memrchr);
 #elif defined GNULIB_POSIXCHECK
 # undef memrchr
 # if HAVE_RAW_DECL_MEMRCHR
@@ -126,9 +165,12 @@
    occur within N bytes.  */
 #if @GNULIB_RAWMEMCHR@
 # if ! @HAVE_RAWMEMCHR@
-extern void *rawmemchr (void const *__s, int __c_in)
-     __attribute__ ((__pure__)) _GL_ARG_NONNULL ((1));
+_GL_FUNCDECL_SYS (rawmemchr, void *, (void const *__s, int __c_in)
+                                     __attribute__ ((__pure__))
+                                     _GL_ARG_NONNULL ((1)));
 # endif
+_GL_CXXALIAS_SYS (rawmemchr, void *, (void const *__s, int __c_in));
+_GL_CXXALIASWARN (rawmemchr);
 #elif defined GNULIB_POSIXCHECK
 # undef rawmemchr
 # if HAVE_RAW_DECL_RAWMEMCHR
@@ -140,9 +182,13 @@
 /* Copy SRC to DST, returning the address of the terminating '\0' in DST.  */
 #if @GNULIB_STPCPY@
 # if ! @HAVE_STPCPY@
-extern char *stpcpy (char *restrict __dst, char const *restrict __src)
-     _GL_ARG_NONNULL ((1, 2));
+_GL_FUNCDECL_SYS (stpcpy, char *,
+                  (char *restrict __dst, char const *restrict __src)
+                  _GL_ARG_NONNULL ((1, 2)));
 # endif
+_GL_CXXALIAS_SYS (stpcpy, char *,
+                  (char *restrict __dst, char const *restrict __src));
+_GL_CXXALIASWARN (stpcpy);
 #elif defined GNULIB_POSIXCHECK
 # undef stpcpy
 # if HAVE_RAW_DECL_STPCPY
@@ -155,11 +201,22 @@
    last non-NUL byte written into DST.  */
 #if @GNULIB_STPNCPY@
 # if ! @HAVE_STPNCPY@
-#  define stpncpy gnu_stpncpy
-extern char *stpncpy (char *restrict __dst, char const *restrict __src,
-                      size_t __n)
-     _GL_ARG_NONNULL ((1, 2));
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   define stpncpy rpl_stpncpy
+#  endif
+_GL_FUNCDECL_RPL (stpncpy, char *,
+                  (char *restrict __dst, char const *restrict __src,
+                   size_t __n)
+                  _GL_ARG_NONNULL ((1, 2)));
+_GL_CXXALIAS_RPL (stpncpy, char *,
+                  (char *restrict __dst, char const *restrict __src,
+                   size_t __n));
+# else
+_GL_CXXALIAS_SYS (stpncpy, char *,
+                  (char *restrict __dst, char const *restrict __src,
+                   size_t __n));
 # endif
+_GL_CXXALIASWARN (stpncpy);
 #elif defined GNULIB_POSIXCHECK
 # undef stpncpy
 # if HAVE_RAW_DECL_STPNCPY
@@ -181,9 +238,12 @@
 /* Find the first occurrence of C in S or the final NUL byte.  */
 #if @GNULIB_STRCHRNUL@
 # if ! @HAVE_STRCHRNUL@
-extern char *strchrnul (char const *__s, int __c_in)
-     __attribute__ ((__pure__)) _GL_ARG_NONNULL ((1));
+_GL_FUNCDECL_SYS (strchrnul, char *, (char const *__s, int __c_in)
+                                     __attribute__ ((__pure__))
+                                     _GL_ARG_NONNULL ((1)));
 # endif
+_GL_CXXALIAS_SYS (strchrnul, char *, (char const *__s, int __c_in));
+_GL_CXXALIASWARN (strchrnul);
 #elif defined GNULIB_POSIXCHECK
 # undef strchrnul
 # if HAVE_RAW_DECL_STRCHRNUL
@@ -195,12 +255,19 @@
 /* Duplicate S, returning an identical malloc'd string.  */
 #if @GNULIB_STRDUP@
 # if @REPLACE_STRDUP@
-#  undef strdup
-#  define strdup rpl_strdup
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef strdup
+#   define strdup rpl_strdup
+#  endif
+_GL_FUNCDECL_RPL (strdup, char *, (char const *__s) _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (strdup, char *, (char const *__s));
+# else
+#  if !(@HAVE_DECL_STRDUP@ || defined strdup)
+_GL_FUNCDECL_SYS (strdup, char *, (char const *__s) _GL_ARG_NONNULL ((1)));
+#  endif
+_GL_CXXALIAS_SYS (strdup, char *, (char const *__s));
 # endif
-# if !(@HAVE_DECL_STRDUP@ || defined strdup) || @REPLACE_STRDUP@
-extern char *strdup (char const *__s) _GL_ARG_NONNULL ((1));
-# endif
+_GL_CXXALIASWARN (strdup);
 #elif defined GNULIB_POSIXCHECK
 # undef strdup
 # if HAVE_RAW_DECL_STRDUP
@@ -212,12 +279,21 @@
 /* Return a newly allocated copy of at most N bytes of STRING.  */
 #if @GNULIB_STRNDUP@
 # if @REPLACE_STRNDUP@
-#  undef strndup
-#  define strndup rpl_strndup
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef strndup
+#   define strndup rpl_strndup
+#  endif
+_GL_FUNCDECL_RPL (strndup, char *, (char const *__string, size_t __n)
+                                   _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (strndup, char *, (char const *__string, size_t __n));
+# else
+#  if ! @HAVE_DECL_STRNDUP@
+_GL_FUNCDECL_SYS (strndup, char *, (char const *__string, size_t __n)
+                                   _GL_ARG_NONNULL ((1)));
+#  endif
+_GL_CXXALIAS_SYS (strndup, char *, (char const *__string, size_t __n));
 # endif
-# if @REPLACE_STRNDUP@ || ! @HAVE_DECL_STRNDUP@
-extern char *strndup (char const *__string, size_t __n) _GL_ARG_NONNULL ((1));
-# endif
+_GL_CXXALIASWARN (strndup);
 #elif defined GNULIB_POSIXCHECK
 # undef strndup
 # if HAVE_RAW_DECL_STRNDUP
@@ -231,9 +307,12 @@
    return MAXLEN.  */
 #if @GNULIB_STRNLEN@
 # if ! @HAVE_DECL_STRNLEN@
-extern size_t strnlen (char const *__string, size_t __maxlen)
-     __attribute__ ((__pure__)) _GL_ARG_NONNULL ((1));
+_GL_FUNCDECL_SYS (strnlen, size_t, (char const *__string, size_t __maxlen)
+                                   __attribute__ ((__pure__))
+                                   _GL_ARG_NONNULL ((1)));
 # endif
+_GL_CXXALIAS_SYS (strnlen, size_t, (char const *__string, size_t __maxlen));
+_GL_CXXALIASWARN (strnlen);
 #elif defined GNULIB_POSIXCHECK
 # undef strnlen
 # if HAVE_RAW_DECL_STRNLEN
@@ -257,9 +336,24 @@
 /* Find the first occurrence in S of any character in ACCEPT.  */
 #if @GNULIB_STRPBRK@
 # if ! @HAVE_STRPBRK@
-extern char *strpbrk (char const *__s, char const *__accept)
-     __attribute__ ((__pure__)) _GL_ARG_NONNULL ((1, 2));
+_GL_FUNCDECL_SYS (strpbrk, char *, (char const *__s, char const *__accept)
+                                   __attribute__ ((__pure__))
+                                   _GL_ARG_NONNULL ((1, 2)));
 # endif
+# if defined __SUNPRO_CC
+  /* This compiler defines an overloaded function
+       extern "C" { const char * strpbrk (const char *, const char *); }
+       extern "C++" { inline char * strpbrk (char *, const char *); }
+     and diagnoses an error
+     "Error: Could not find a match for std::strpbrk(const char*, const char*)"
+   */
+_GL_CXXALIAS_SYS_CAST2 (strpbrk,
+                        char *, (char const *__s, char const *__accept),
+                        const char *, (char const *__s, char const *__accept));
+# else
+_GL_CXXALIAS_SYS (strpbrk, char *, (char const *__s, char const *__accept));
+# endif
+_GL_CXXALIASWARN (strpbrk);
 # if defined GNULIB_POSIXCHECK
 /* strpbrk() assumes the second argument is a list of single-byte characters.
    Even in this simple case, it does not work with multibyte strings if the
@@ -316,9 +410,13 @@
    See also strtok_r().  */
 #if @GNULIB_STRSEP@
 # if ! @HAVE_STRSEP@
-extern char *strsep (char **restrict __stringp, char const *restrict __delim)
-     _GL_ARG_NONNULL ((1, 2));
+_GL_FUNCDECL_SYS (strsep, char *,
+                  (char **restrict __stringp, char const *restrict __delim)
+                  _GL_ARG_NONNULL ((1, 2)));
 # endif
+_GL_CXXALIAS_SYS (strsep, char *,
+                  (char **restrict __stringp, char const *restrict __delim));
+_GL_CXXALIASWARN (strsep);
 # if defined GNULIB_POSIXCHECK
 #  undef strsep
 _GL_WARN_ON_USE (strsep, "strsep cannot work correctly on character strings "
@@ -335,10 +433,17 @@
 
 #if @GNULIB_STRSTR@
 # if @REPLACE_STRSTR@
-#  define strstr rpl_strstr
-extern char *strstr (const char *haystack, const char *needle)
-     __attribute__ ((__pure__)) _GL_ARG_NONNULL ((1, 2));
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   define strstr rpl_strstr
+#  endif
+_GL_FUNCDECL_RPL (strstr, char *, (const char *haystack, const char *needle)
+                                  __attribute__ ((__pure__))
+                                  _GL_ARG_NONNULL ((1, 2)));
+_GL_CXXALIAS_RPL (strstr, char *, (const char *haystack, const char *needle));
+# else
+_GL_CXXALIAS_SYS (strstr, char *, (const char *haystack, const char *needle));
 # endif
+_GL_CXXALIASWARN (strstr);
 #elif defined GNULIB_POSIXCHECK
 /* strstr() does not work with multibyte strings if the locale encoding is
    different from UTF-8:
@@ -357,12 +462,24 @@
    comparison.  */
 #if @GNULIB_STRCASESTR@
 # if @REPLACE_STRCASESTR@
-#  define strcasestr rpl_strcasestr
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   define strcasestr rpl_strcasestr
+#  endif
+_GL_FUNCDECL_RPL (strcasestr, char *,
+                  (const char *haystack, const char *needle)
+                  __attribute__ ((__pure__)) _GL_ARG_NONNULL ((1, 2)));
+_GL_CXXALIAS_RPL (strcasestr, char *,
+                  (const char *haystack, const char *needle));
+# else
+#  if ! @HAVE_STRCASESTR@
+_GL_FUNCDECL_SYS (strcasestr, char *,
+                  (const char *haystack, const char *needle)
+                  __attribute__ ((__pure__)) _GL_ARG_NONNULL ((1, 2)));
+#  endif
+_GL_CXXALIAS_SYS (strcasestr, char *,
+                  (const char *haystack, const char *needle));
 # endif
-# if ! @HAVE_STRCASESTR@ || @REPLACE_STRCASESTR@
-extern char *strcasestr (const char *haystack, const char *needle)
-     __attribute__ ((__pure__)) _GL_ARG_NONNULL ((1, 2));
-# endif
+_GL_CXXALIASWARN (strcasestr);
 #elif defined GNULIB_POSIXCHECK
 /* strcasestr() does not work with multibyte strings:
    It is a glibc extension, and glibc implements it only for unibyte
@@ -401,16 +518,32 @@
    See also strsep().  */
 #if @GNULIB_STRTOK_R@
 # if @REPLACE_STRTOK_R@
-#  undef strtok_r
-#  define strtok_r rpl_strtok_r
-# elif @UNDEFINE_STRTOK_R@ || defined GNULIB_POSIXCHECK
-#  undef strtok_r
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef strtok_r
+#   define strtok_r rpl_strtok_r
+#  endif
+_GL_FUNCDECL_RPL (strtok_r, char *,
+                  (char *restrict s, char const *restrict delim,
+                   char **restrict save_ptr)
+                  _GL_ARG_NONNULL ((2, 3)));
+_GL_CXXALIAS_RPL (strtok_r, char *,
+                  (char *restrict s, char const *restrict delim,
+                   char **restrict save_ptr));
+# else
+#  if @UNDEFINE_STRTOK_R@ || defined GNULIB_POSIXCHECK
+#   undef strtok_r
+#  endif
+#  if ! @HAVE_DECL_STRTOK_R@
+_GL_FUNCDECL_SYS (strtok_r, char *,
+                  (char *restrict s, char const *restrict delim,
+                   char **restrict save_ptr)
+                  _GL_ARG_NONNULL ((2, 3)));
+#  endif
+_GL_CXXALIAS_SYS (strtok_r, char *,
+                  (char *restrict s, char const *restrict delim,
+                   char **restrict save_ptr));
 # endif
-# if ! @HAVE_DECL_STRTOK_R@ || @REPLACE_STRTOK_R@
-extern char *strtok_r (char *restrict s, char const *restrict delim,
-                       char **restrict save_ptr)
-     _GL_ARG_NONNULL ((2, 3));
-# endif
+_GL_CXXALIASWARN (strtok_r);
 # if defined GNULIB_POSIXCHECK
 _GL_WARN_ON_USE (strtok_r, "strtok_r cannot work correctly on character "
                  "strings in multibyte locales - "
@@ -435,15 +568,23 @@
 #  undef mbslen
 # endif
 # if @HAVE_MBSLEN@  /* AIX, OSF/1, MirBSD define mbslen already in libc.  */
-#  define mbslen rpl_mbslen
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   define mbslen rpl_mbslen
+#  endif
+_GL_FUNCDECL_RPL (mbslen, size_t, (const char *string) _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (mbslen, size_t, (const char *string));
+# else
+_GL_FUNCDECL_SYS (mbslen, size_t, (const char *string) _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_SYS (mbslen, size_t, (const char *string));
 # endif
-extern size_t mbslen (const char *string) _GL_ARG_NONNULL ((1));
+_GL_CXXALIASWARN (mbslen);
 #endif
 
 #if @GNULIB_MBSNLEN@
 /* Return the number of multibyte characters in the character string starting
    at STRING and ending at STRING + LEN.  */
-extern size_t mbsnlen (const char *string, size_t len) _GL_ARG_NONNULL ((1));
+_GL_EXTERN_C size_t mbsnlen (const char *string, size_t len)
+     _GL_ARG_NONNULL ((1));
 #endif
 
 #if @GNULIB_MBSCHR@
@@ -451,8 +592,19 @@
    and return a pointer to it.  Return NULL if C is not found in STRING.
    Unlike strchr(), this function works correctly in multibyte locales with
    encodings such as GB18030.  */
-# define mbschr rpl_mbschr /* avoid collision with HP-UX function */
-extern char * mbschr (const char *string, int c) _GL_ARG_NONNULL ((1));
+# if defined __hpux
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   define mbschr rpl_mbschr /* avoid collision with HP-UX function */
+#  endif
+_GL_FUNCDECL_RPL (mbschr, char *, (const char *string, int c)
+                                  _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (mbschr, char *, (const char *string, int c));
+# else
+_GL_FUNCDECL_SYS (mbschr, char *, (const char *string, int c)
+                                  _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_SYS (mbschr, char *, (const char *string, int c));
+# endif
+_GL_CXXALIASWARN (mbschr);
 #endif
 
 #if @GNULIB_MBSRCHR@
@@ -460,8 +612,19 @@
    and return a pointer to it.  Return NULL if C is not found in STRING.
    Unlike strrchr(), this function works correctly in multibyte locales with
    encodings such as GB18030.  */
-# define mbsrchr rpl_mbsrchr /* avoid collision with HP-UX function */
-extern char * mbsrchr (const char *string, int c) _GL_ARG_NONNULL ((1));
+# if defined __hpux
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   define mbsrchr rpl_mbsrchr /* avoid collision with HP-UX function */
+#  endif
+_GL_FUNCDECL_RPL (mbsrchr, char *, (const char *string, int c)
+                                   _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (mbsrchr, char *, (const char *string, int c));
+# else
+_GL_FUNCDECL_SYS (mbsrchr, char *, (const char *string, int c)
+                                   _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_SYS (mbsrchr, char *, (const char *string, int c));
+# endif
+_GL_CXXALIASWARN (mbsrchr);
 #endif
 
 #if @GNULIB_MBSSTR@
@@ -469,7 +632,7 @@
    string HAYSTACK.  Return NULL if NEEDLE is not found in HAYSTACK.
    Unlike strstr(), this function works correctly in multibyte locales with
    encodings different from UTF-8.  */
-extern char * mbsstr (const char *haystack, const char *needle)
+_GL_EXTERN_C char * mbsstr (const char *haystack, const char *needle)
      _GL_ARG_NONNULL ((1, 2));
 #endif
 
@@ -480,7 +643,7 @@
    Note: This function may, in multibyte locales, return 0 for strings of
    different lengths!
    Unlike strcasecmp(), this function works correctly in multibyte locales.  */
-extern int mbscasecmp (const char *s1, const char *s2)
+_GL_EXTERN_C int mbscasecmp (const char *s1, const char *s2)
      _GL_ARG_NONNULL ((1, 2));
 #endif
 
@@ -494,7 +657,7 @@
    of different lengths!
    Unlike strncasecmp(), this function works correctly in multibyte locales.
    But beware that N is not a byte count but a character count!  */
-extern int mbsncasecmp (const char *s1, const char *s2, size_t n)
+_GL_EXTERN_C int mbsncasecmp (const char *s1, const char *s2, size_t n)
      _GL_ARG_NONNULL ((1, 2));
 #endif
 
@@ -508,7 +671,7 @@
    smaller length than PREFIX!
    Unlike strncasecmp(), this function works correctly in multibyte
    locales.  */
-extern char * mbspcasecmp (const char *string, const char *prefix)
+_GL_EXTERN_C char * mbspcasecmp (const char *string, const char *prefix)
      _GL_ARG_NONNULL ((1, 2));
 #endif
 
@@ -518,7 +681,7 @@
    Note: This function may, in multibyte locales, return success even if
    strlen (haystack) < strlen (needle) !
    Unlike strcasestr(), this function works correctly in multibyte locales.  */
-extern char * mbscasestr (const char *haystack, const char *needle)
+_GL_EXTERN_C char * mbscasestr (const char *haystack, const char *needle)
      _GL_ARG_NONNULL ((1, 2));
 #endif
 
@@ -528,7 +691,7 @@
    beginning of the string to this occurrence, or to the end of the string
    if none exists.
    Unlike strcspn(), this function works correctly in multibyte locales.  */
-extern size_t mbscspn (const char *string, const char *accept)
+_GL_EXTERN_C size_t mbscspn (const char *string, const char *accept)
      _GL_ARG_NONNULL ((1, 2));
 #endif
 
@@ -537,9 +700,19 @@
    in the character string ACCEPT.  Return the pointer to it, or NULL if none
    exists.
    Unlike strpbrk(), this function works correctly in multibyte locales.  */
-# define mbspbrk rpl_mbspbrk /* avoid collision with HP-UX function */
-extern char * mbspbrk (const char *string, const char *accept)
-     _GL_ARG_NONNULL ((1, 2));
+# if defined __hpux
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   define mbspbrk rpl_mbspbrk /* avoid collision with HP-UX function */
+#  endif
+_GL_FUNCDECL_RPL (mbspbrk, char *, (const char *string, const char *accept)
+                                   _GL_ARG_NONNULL ((1, 2)));
+_GL_CXXALIAS_RPL (mbspbrk, char *, (const char *string, const char *accept));
+# else
+_GL_FUNCDECL_SYS (mbspbrk, char *, (const char *string, const char *accept)
+                                   _GL_ARG_NONNULL ((1, 2)));
+_GL_CXXALIAS_SYS (mbspbrk, char *, (const char *string, const char *accept));
+# endif
+_GL_CXXALIASWARN (mbspbrk);
 #endif
 
 #if @GNULIB_MBSSPN@
@@ -548,7 +721,7 @@
    beginning of the string to this occurrence, or to the end of the string
    if none exists.
    Unlike strspn(), this function works correctly in multibyte locales.  */
-extern size_t mbsspn (const char *string, const char *reject)
+_GL_EXTERN_C size_t mbsspn (const char *string, const char *reject)
      _GL_ARG_NONNULL ((1, 2));
 #endif
 
@@ -567,7 +740,7 @@
    Caveat: The identity of the delimiting character is lost.
 
    See also mbstok_r().  */
-extern char * mbssep (char **stringp, const char *delim)
+_GL_EXTERN_C char * mbssep (char **stringp, const char *delim)
      _GL_ARG_NONNULL ((1, 2));
 #endif
 
@@ -588,17 +761,23 @@
    Caveat: The identity of the delimiting character is lost.
 
    See also mbssep().  */
-extern char * mbstok_r (char *string, const char *delim, char **save_ptr)
+_GL_EXTERN_C char * mbstok_r (char *string, const char *delim, char **save_ptr)
      _GL_ARG_NONNULL ((2, 3));
 #endif
 
 /* Map any int, typically from errno, into an error message.  */
 #if @GNULIB_STRERROR@
 # if @REPLACE_STRERROR@
-#  undef strerror
-#  define strerror rpl_strerror
-extern char *strerror (int);
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef strerror
+#   define strerror rpl_strerror
+#  endif
+_GL_FUNCDECL_RPL (strerror, char *, (int));
+_GL_CXXALIAS_RPL (strerror, char *, (int));
+# else
+_GL_CXXALIAS_SYS (strerror, char *, (int));
 # endif
+_GL_CXXALIASWARN (strerror);
 #elif defined GNULIB_POSIXCHECK
 # undef strerror
 /* Assume strerror is always declared.  */
@@ -608,11 +787,20 @@
 
 #if @GNULIB_STRSIGNAL@
 # if @REPLACE_STRSIGNAL@
-#  define strsignal rpl_strsignal
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   define strsignal rpl_strsignal
+#  endif
+_GL_FUNCDECL_RPL (strsignal, char *, (int __sig));
+_GL_CXXALIAS_RPL (strsignal, char *, (int __sig));
+# else
+#  if ! @HAVE_DECL_STRSIGNAL@
+_GL_FUNCDECL_SYS (strsignal, char *, (int __sig));
+#  endif
+/* Need to cast, because on Cygwin 1.5.x systems, the return type is
+   'const char *'.  */
+_GL_CXXALIAS_SYS_CAST (strsignal, char *, (int __sig));
 # endif
-# if ! @HAVE_DECL_STRSIGNAL@ || @REPLACE_STRSIGNAL@
-extern char *strsignal (int __sig);
-# endif
+_GL_CXXALIASWARN (strsignal);
 #elif defined GNULIB_POSIXCHECK
 # undef strsignal
 # if HAVE_RAW_DECL_STRSIGNAL
@@ -623,8 +811,11 @@
 
 #if @GNULIB_STRVERSCMP@
 # if !@HAVE_STRVERSCMP@
-extern int strverscmp (const char *, const char *) _GL_ARG_NONNULL ((1, 2));
+_GL_FUNCDECL_SYS (strverscmp, int, (const char *, const char *)
+                                   _GL_ARG_NONNULL ((1, 2)));
 # endif
+_GL_CXXALIAS_SYS (strverscmp, int, (const char *, const char *));
+_GL_CXXALIASWARN (strverscmp);
 #elif defined GNULIB_POSIXCHECK
 # undef strverscmp
 # if HAVE_RAW_DECL_STRVERSCMP
@@ -634,9 +825,5 @@
 #endif
 
 
-#ifdef __cplusplus
-}
-#endif
-
 #endif /* _GL_STRING_H */
 #endif /* _GL_STRING_H */

--- a/modules/string
+++ b/modules/string
@@ -7,6 +7,7 @@
 
 Depends-on:
 arg-nonnull
+c++defs
 extensions
 include_next
 stddef
@@ -20,7 +21,7 @@
 
 # We need the following in order to create <string.h> when the system
 # doesn't have one that works with the given compiler.
-string.h: string.in.h $(WARN_ON_USE_H) $(ARG_NONNULL_H)
+string.h: string.in.h $(CXXDEFS_H) $(ARG_NONNULL_H) $(WARN_ON_USE_H)
 	$(AM_V_GEN)rm -f $@-t $@ && \
 	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */' && \
 	  sed -e 's|@''INCLUDE_NEXT''@|$(INCLUDE_NEXT)|g' \
@@ -88,6 +89,7 @@
 	      -e 's|@''REPLACE_STRSIGNAL''@|$(REPLACE_STRSIGNAL)|g' \
 	      -e 's|@''REPLACE_STRTOK_R''@|$(REPLACE_STRTOK_R)|g' \
 	      -e 's|@''UNDEFINE_STRTOK_R''@|$(UNDEFINE_STRTOK_R)|g' \
+	      -e '/definitions of _GL_FUNCDECL_RPL/r $(CXXDEFS_H)' \
 	      -e '/definition of _GL_ARG_NONNULL/r $(ARG_NONNULL_H)' \
 	      -e '/definition of _GL_WARN_ON_USE/r $(WARN_ON_USE_H)'; \
 	      < $(srcdir)/string.in.h; \