1 files changed, 26 insertions, 0 deletions
diff --git a/libcutl/meta/class-p.hxx b/libcutl/meta/class-p.hxx
new file mode 100644
index 0000000..fc7a111
--- /dev/null
+++ b/libcutl/meta/class-p.hxx
@@ -0,0 +1,26 @@
+// file      : libcutl/meta/class-p.hxx
+// license   : MIT; see accompanying LICENSE file
+
+#ifndef LIBCUTL_META_CLASS_HXX
+#define LIBCUTL_META_CLASS_HXX
+
+#include <libcutl/meta/answer.hxx>
+
+namespace cutl
+{
+  namespace meta
+  {
+    // g++ cannot have these inside class_p.
+    //
+    template <typename Y> no class_p_test (...);
+    template <typename Y> yes class_p_test (void (Y::*) ());
+
+    template <typename X>
+    struct class_p
+    {
+      static bool const r = sizeof (class_p_test<X> (0)) == sizeof (yes);
+    };
+  }
+}
+
+#endif // LIBCUTL_META_CLASS_HXX