--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,13 @@
 2010-03-07  Bruno Haible  <bruno@clisp.org>
 
+	Tests of module 'string' in C++ mode.
+	* tests/test-string-c++.cc: New file.
+	* modules/string-tests (Files): Add it and tests/signature.h.
+	(Depends-on): Add ansi-c++-opt.
+	(Makefile.am): Arrange to compile and run test-string-c++.
+	* m4/string_h.m4 (gl_STRING_MODULE_INDICATOR): Invoke
+	gl_MODULE_INDICATOR.
+
 	Tests of module 'stdlib' in C++ mode.
 	* tests/test-stdlib-c++.cc: New file.
 	* modules/stdlib-tests (Files): Add it and tests/signature.h.

--- a/m4/string_h.m4
+++ b/m4/string_h.m4
@@ -5,7 +5,7 @@
 # gives unlimited permission to copy and/or distribute it,
 # with or without modifications, as long as this notice is preserved.
 
-# serial 11
+# serial 12
 
 # Written by Paul Eggert.
 
@@ -35,6 +35,8 @@
   dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
   AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
   GNULIB_[]m4_translit([$1],[abcdefghijklmnopqrstuvwxyz./-],[ABCDEFGHIJKLMNOPQRSTUVWXYZ___])=1
+  dnl Define it also as a C macro, for the benefit of the unit tests.
+  gl_MODULE_INDICATOR([$1])
 ])
 
 AC_DEFUN([gl_HEADER_STRING_H_DEFAULTS],

--- a/modules/string-tests
+++ b/modules/string-tests
@@ -1,11 +1,20 @@
 Files:
 tests/test-string.c
+tests/test-string-c++.cc
+tests/signature.h
 
 Depends-on:
 verify
+ansi-c++-opt
 
 configure.ac:
 
 Makefile.am:
 TESTS += test-string
 check_PROGRAMS += test-string
+if ANSICXX
+TESTS += test-string-c++
+check_PROGRAMS += test-string-c++
+test_string_c___SOURCES = test-string-c++.cc
+test_string_c___LDADD = $(LDADD) $(LIBINTL)
+endif

new file mode 100644
--- /dev/null
+++ b/tests/test-string-c++.cc
@@ -0,0 +1,137 @@
+/* Test of <string.h> substitute in C++ mode.
+   Copyright (C) 2010 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2010.  */
+
+#define GNULIB_NAMESPACE gnulib
+#include <config.h>
+
+#include <string.h>
+
+#include "signature.h"
+
+
+#if GNULIB_MEMCHR
+SIGNATURE_CHECK (GNULIB_NAMESPACE::memchr, void *,
+                 (void const *, int, size_t));
+#endif
+
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::memcmp, int,
+//                 (void const *, void const *, size_t));
+
+#if GNULIB_MEMMEM
+SIGNATURE_CHECK (GNULIB_NAMESPACE::memmem, void *,
+                 (void const *, size_t, void const *, size_t));
+#endif
+
+#if GNULIB_MEMPCPY
+SIGNATURE_CHECK (GNULIB_NAMESPACE::mempcpy, void *,
+                 (void *, void const *, size_t));
+#endif
+
+#if GNULIB_MEMRCHR
+SIGNATURE_CHECK (GNULIB_NAMESPACE::memrchr, void *,
+                 (void const *, int, size_t));
+#endif
+
+#if GNULIB_RAWMEMCHR
+SIGNATURE_CHECK (GNULIB_NAMESPACE::rawmemchr, void *, (void const *, int));
+#endif
+
+#if GNULIB_STPCPY
+SIGNATURE_CHECK (GNULIB_NAMESPACE::stpcpy, char *, (char *, char const *));
+#endif
+
+#if GNULIB_STPNCPY
+SIGNATURE_CHECK (GNULIB_NAMESPACE::stpncpy, char *,
+                 (char *, char const *, size_t));
+#endif
+
+#if GNULIB_STRCHRNUL
+SIGNATURE_CHECK (GNULIB_NAMESPACE::strchrnul, char *, (char const *, int));
+#endif
+
+#if GNULIB_STRDUP
+SIGNATURE_CHECK (GNULIB_NAMESPACE::strdup, char *, (char const *));
+#endif
+
+#if GNULIB_STRNDUP
+SIGNATURE_CHECK (GNULIB_NAMESPACE::strndup, char *, (char const *, size_t));
+#endif
+
+#if GNULIB_STRNLEN
+SIGNATURE_CHECK (GNULIB_NAMESPACE::strnlen, size_t, (char const *, size_t));
+#endif
+
+#if GNULIB_STRPBRK
+SIGNATURE_CHECK (GNULIB_NAMESPACE::strpbrk, char *,
+                 (char const *, char const *));
+#endif
+
+#if GNULIB_STRSEP
+SIGNATURE_CHECK (GNULIB_NAMESPACE::strsep, char *, (char **, char const *));
+#endif
+
+#if GNULIB_STRSTR
+SIGNATURE_CHECK (GNULIB_NAMESPACE::strstr, char *,
+                 (const char *, const char *));
+#endif
+
+#if GNULIB_STRCASESTR
+SIGNATURE_CHECK (GNULIB_NAMESPACE::strcasestr, char *,
+                 (const char *, const char *));
+#endif
+
+#if GNULIB_STRTOK_R
+SIGNATURE_CHECK (GNULIB_NAMESPACE::strtok_r, char *,
+                 (char *, char const *, char **));
+#endif
+
+#if GNULIB_MBSLEN
+SIGNATURE_CHECK (GNULIB_NAMESPACE::mbslen, size_t, (const char *));
+#endif
+
+#if GNULIB_MBSCHR
+SIGNATURE_CHECK (GNULIB_NAMESPACE::mbschr, char *, (const char *, int));
+#endif
+
+#if GNULIB_MBSRCHR
+SIGNATURE_CHECK (GNULIB_NAMESPACE::mbsrchr, char *, (const char *, int));
+#endif
+
+#if GNULIB_MBSPBRK
+SIGNATURE_CHECK (GNULIB_NAMESPACE::mbspbrk, char *,
+                 (const char *, const char *));
+#endif
+
+#if GNULIB_STRERROR
+SIGNATURE_CHECK (GNULIB_NAMESPACE::strerror, char *, (int));
+#endif
+
+#if GNULIB_STRSIGNAL
+SIGNATURE_CHECK (GNULIB_NAMESPACE::strsignal, char *, (int));
+#endif
+
+#if GNULIB_STRVERSCMP
+SIGNATURE_CHECK (GNULIB_NAMESPACE::strverscmp, int,
+                 (const char *, const char *));
+#endif
+
+
+int
+main ()
+{
+}