Simplify memory manager

ctl/is_void.h

@@ -0,0 +1,24 @@
+// -*-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_IS_VOID_H_
+#define CTL_IS_VOID_H_
+#include "integral_constant.h"
+#include "remove_cv.h"
+
+namespace ctl {
+
+template<typename>
+struct is_void_ : public ctl::false_type
+{};
+
+template<>
+struct is_void_<void> : public ctl::true_type
+{};
+
+template<typename _Tp>
+struct is_void : public is_void_<typename ctl::remove_cv<_Tp>::type>::type
+{};
+
+} // namespace ctl
+
+#endif // CTL_IS_VOID_H_

ctl/vector.h

@@ -525,7 +525,7 @@ class vector
         capacity_ = new_capacity;
     }
 
-    Allocator alloc_;
+    [[no_unique_address]] Allocator alloc_;
     pointer data_;
     size_type size_;
     size_type capacity_;