Update configure test for G++ to work with new autoconf.

diff --git a/configure.ac b/configure.ac
index 606f552f505c851d022ddaa7449540e34c5126f7..f4ec939b82802aafb69fa005c2c6b1c243beef32 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -440,7 +440,7 @@ dnl ---------------------------------------------------------------------------
 AC_CACHE_CHECK([C++ compiler availability], [ac_cv_libmapixx_gxx_works],
               [
                AC_LANG_PUSH([C++])
-               AC_COMPILE_IFELSE([int main() { return 0; }], 
+               AC_COMPILE_IFELSE([AC_LANG_SOURCE([[int main() { return 0; }]])], 
                                  [ac_cv_libmapixx_gxx_works=yes],
                                  [ac_cv_libmapixx_gxx_works=no])
                AC_LANG_POP([C++])