--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 2010-03-07  Bruno Haible  <bruno@clisp.org>
 
+	Tests of module 'math' in C++ mode.
+	* tests/test-math-c++.cc: New file.
+	* modules/math-tests (Files): Add it and tests/signature.h.
+	(Depends-on): Add ansi-c++-opt.
+	(Makefile.am): Arrange to compile and run test-math-c++.
+	* m4/math_h.m4 (gl_MATH_MODULE_INDICATOR): Invoke gl_MODULE_INDICATOR.
+
 	Tests of module 'locale' in C++ mode.
 	* tests/test-locale-c++.cc: New file.
 	* modules/locale-tests (Files): Add it and tests/signature.h.

--- a/m4/math_h.m4
+++ b/m4/math_h.m4
@@ -1,4 +1,4 @@
-# math_h.m4 serial 18
+# math_h.m4 serial 19
 dnl Copyright (C) 2007-2010 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -48,6 +48,8 @@
   dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
   AC_REQUIRE([gl_MATH_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_MATH_H_DEFAULTS],

--- a/modules/math-tests
+++ b/modules/math-tests
@@ -1,10 +1,18 @@
 Files:
 tests/test-math.c
+tests/test-math-c++.cc
+tests/signature.h
 
 Depends-on:
+ansi-c++-opt
 
 configure.ac:
 
 Makefile.am:
 TESTS += test-math
 check_PROGRAMS += test-math
+if ANSICXX
+TESTS += test-math-c++
+check_PROGRAMS += test-math-c++
+test_math_c___SOURCES = test-math-c++.cc
+endif

new file mode 100644
--- /dev/null
+++ b/tests/test-math-c++.cc
@@ -0,0 +1,155 @@
+/* Test of <math.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 <math.h>
+
+#include "signature.h"
+
+
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::acos, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::asin, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::atan, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::atan2, double, (double, double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::cbrt, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::copysign, double, (double, double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::cos, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::cosh, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::erf, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::erfc, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::exp, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::fabs, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::fmod, double, (double, double));
+#if GNULIB_FREXP
+SIGNATURE_CHECK (GNULIB_NAMESPACE::frexp, double, (double, int *));
+#endif
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::hypot, double, (double, double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::j0, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::j1, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::jn, double, (int, double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::ldexp, double, (double, int));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::lgamma, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::log10, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::log1p, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::logb, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::log, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::modf, double, (double, double *));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::nextafter, double, (double, double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::pow, double, (double, double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::remainder, double, (double, double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::rint, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::sin, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::sinh, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::sqrt, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::tan, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::tanh, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::y0, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::y1, double, (double));
+//SIGNATURE_CHECK (GNULIB_NAMESPACE::yn, double, (int, double));
+
+#if GNULIB_ACOSL
+SIGNATURE_CHECK (GNULIB_NAMESPACE::acosl, long double, (long double));
+#endif
+
+#if GNULIB_ASINL
+SIGNATURE_CHECK (GNULIB_NAMESPACE::asinl, long double, (long double));
+#endif
+
+#if GNULIB_ATANL
+SIGNATURE_CHECK (GNULIB_NAMESPACE::atanl, long double, (long double));
+#endif
+
+#if GNULIB_CEILF
+SIGNATURE_CHECK (GNULIB_NAMESPACE::ceilf, float, (float));
+#endif
+
+#if GNULIB_CEILL
+SIGNATURE_CHECK (GNULIB_NAMESPACE::ceill, long double, (long double));
+#endif
+
+#if GNULIB_COSL
+SIGNATURE_CHECK (GNULIB_NAMESPACE::cosl, long double, (long double));
+#endif
+
+#if GNULIB_EXPL
+SIGNATURE_CHECK (GNULIB_NAMESPACE::expl, long double, (long double));
+#endif
+
+#if GNULIB_FLOORF
+SIGNATURE_CHECK (GNULIB_NAMESPACE::floorf, float, (float));
+#endif
+
+#if GNULIB_FLOORL
+SIGNATURE_CHECK (GNULIB_NAMESPACE::floorl, long double, (long double));
+#endif
+
+#if GNULIB_FREXPL
+SIGNATURE_CHECK (GNULIB_NAMESPACE::frexpl, long double, (long double, int *));
+#endif
+
+#if GNULIB_LDEXPL
+SIGNATURE_CHECK (GNULIB_NAMESPACE::ldexpl, long double, (long double, int));
+#endif
+
+#if GNULIB_LOGL
+SIGNATURE_CHECK (GNULIB_NAMESPACE::logl, long double, (long double));
+#endif
+
+#if GNULIB_ROUNDF
+SIGNATURE_CHECK (GNULIB_NAMESPACE::roundf, float, (float));
+#endif
+
+#if GNULIB_ROUND
+SIGNATURE_CHECK (GNULIB_NAMESPACE::round, double, (double));
+#endif
+
+#if GNULIB_ROUNDL
+SIGNATURE_CHECK (GNULIB_NAMESPACE::roundl, long double, (long double));
+#endif
+
+#if GNULIB_SINL
+SIGNATURE_CHECK (GNULIB_NAMESPACE::sinl, long double, (long double));
+#endif
+
+#if GNULIB_SQRTL
+SIGNATURE_CHECK (GNULIB_NAMESPACE::sqrtl, long double, (long double));
+#endif
+
+#if GNULIB_TANL
+SIGNATURE_CHECK (GNULIB_NAMESPACE::tanl, long double, (long double));
+#endif
+
+#if GNULIB_TRUNCF
+SIGNATURE_CHECK (GNULIB_NAMESPACE::truncf, float, (float));
+#endif
+
+#if GNULIB_TRUNC
+SIGNATURE_CHECK (GNULIB_NAMESPACE::trunc, double, (double));
+#endif
+
+#if GNULIB_TRUNCL
+SIGNATURE_CHECK (GNULIB_NAMESPACE::truncl, long double, (long double));
+#endif
+
+
+int
+main ()
+{
+}