- add test for rvalue references

- fix config.h-comments for variadic templates

[[Imported from SVN: r6308]]

m4/Makefile.am

@@ -12,6 +12,7 @@ ALLM4S = 					\
 	ax_lang_compiler_ms.m4			\
 	boost_fusion.m4				\
 	cxx0x_compiler.m4			\
+	cxx0x_rvaluereference.m4		\
 	cxx0x_nullptr.m4			\
 	cxx0x_static_assert.m4			\
 	cxx0x_variadic.m4			\

m4/cxx0x_rvaluereference.m4

+# tests compiler support for C++0x rvalue references
+# the associated macro is called HAVE_RVALUE_REFERENCES
+
+AC_DEFUN([RVALUE_REFERENCES_CHECK],[
+  AC_REQUIRE([AC_PROG_CXX])
+  AC_REQUIRE([GXX0X])
+  AC_LANG_PUSH([C++])
+  AC_MSG_CHECKING([whether rvalue references are supported])
+  AC_RUN_IFELSE([
+    AC_LANG_PROGRAM([#include<cassert>
+      #include <utility>
+      int foo(int&& x) { return 1; }
+      int foo(const int& x) { return -1; }
+
+      template<typename T>
+      int forward(T&& x)
+      {
+          return foo(std::forward<T>(x));
+      }], 
+      [
+        int i = 0;
+        assert( forward(i) + forward(int(2)) == 0);
+        return 0;
+      ])],[
+    HAVE_RVALUE_REFERENCES=yes
+    AC_MSG_RESULT(yes)], [
+    HAVE_RVALUE_REFERENCES=no
+    AC_MSG_RESULT(no)])
+  if test "x$HAVE_RVALUe_REFERENCES" = xyes; then
+    AC_DEFINE(HAVE_RVALUE_REFERENCES, 1, [Define to 1 if rvalue references are supported])
+  fi
+  AC_LANG_POP
+])

m4/cxx0x_variadic.m4

@@ -31,7 +31,7 @@ AC_DEFUN([VARIADIC_TEMPLATES_CHECK],[
     HAVE_VARIADIC_TEMPLATES=no
     AC_MSG_RESULT(no)])
   if test "x$HAVE_VARIADIC_TEMPLATES" = xyes; then
-    AC_DEFINE(HAVE_VARIADIC_TEMPLATES, 1, [Define to 1 if nullptr is supported])
+    AC_DEFINE(HAVE_VARIADIC_TEMPLATES, 1, [Define to 1 if variadic templates are supported])
   fi
   AC_LANG_POP
 ])