Add more AX_ macros

etc/m4/ax_cxx_templates.m4

@@ -0,0 +1,43 @@
+# ===========================================================================
+#     https://www.gnu.org/software/autoconf-archive/ax_cxx_templates.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_CXX_TEMPLATES
+#
+# DESCRIPTION
+#
+#   If the compiler supports basic templates, define HAVE_TEMPLATES.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Todd Veldhuizen
+#   Copyright (c) 2008 Luc Maisonobe <luc@spaceroots.org>
+#
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved. This file is offered as-is, without any
+#   warranty.
+
+#serial 8
+
+AU_ALIAS([AC_CXX_TEMPLATES], [AX_CXX_TEMPLATES])
+AC_DEFUN([AX_CXX_TEMPLATES],
+[dnl
+  AC_CACHE_CHECK([whether the compiler supports basic templates],
+    [ax_cv_cxx_templates],
+    [AC_LANG_PUSH([C++])
+     AC_COMPILE_IFELSE([dnl
+       AC_LANG_PROGRAM([
+           template<class T> class A {public:A(){};};
+           template<class T> void f(const A<T>& ){};
+         ],
+         [A<double> d; A<int> i; f(d); f(i); return 0;])],
+       [ax_cv_cxx_templates=yes],
+       [ax_cv_cxx_templates=no])
+     AC_LANG_POP([C++])
+  ])
+  AS_IF([test "X$ax_cv_cxx_templates" = "Xyes"],
+        [AC_DEFINE(HAVE_TEMPLATES,,[define if the compiler supports basic templates])])
+])