Add more CTL content

ctl/decay.h

@@ -0,0 +1,35 @@
+// -*-mode:c++;indent-tabs-mode:nil;c-basic-offset:4;tab-width:8;coding:utf-8-*-
+// vi: set et ft=cpp ts=4 sts=4 sw=4 fenc=utf-8 :vi
+#ifndef CTL_DECAY_H_
+#define CTL_DECAY_H_
+#include "add_pointer.h"
+#include "conditional.h"
+#include "is_array.h"
+#include "is_function.h"
+#include "remove_cv.h"
+#include "remove_extent.h"
+#include "remove_reference.h"
+
+namespace ctl {
+
+template<typename T>
+struct decay
+{
+  private:
+    typedef typename remove_reference<T>::type U;
+
+  public:
+    typedef typename conditional<
+      is_array<U>::value,
+      typename remove_extent<U>::type*,
+      typename conditional<is_function<U>::value,
+                           typename add_pointer<U>::type,
+                           typename remove_cv<U>::type>::type>::type type;
+};
+
+template<typename T>
+using decay_t = typename decay<T>::type;
+
+} // namespace ctl
+
+#endif // CTL_DECAY_H_