Fixed compile error due to MS using _MSC_VER rather than __cplusplus

smartptr.h

@@ -2,12 +2,30 @@
 #define CRYPTOPP_SMARTPTR_H
 
 #include "config.h"
+#include "stdcpp.h"
 #include "trap.h"
 
-#include <algorithm>
-
 NAMESPACE_BEGIN(CryptoPP)
 
+// This must be kept in sync with stdcpp.h because <memory> is included based on the same logic.
+#if ((__cplusplus >= 201103L) || (_MSC_VER >= 1600)) && !defined(__clang__)
+#    include <memory>
+  template<typename T>
+    using auto_ptr = std::unique_ptr<T>;
+#elif defined(__clang__)
+#   if (__has_include(<tr1/memory>))
+#      include <tr1/memory>
+  using std::auto_ptr;
+#   endif
+#elif (__cplusplus < 201103L)
+#   include <tr1/memory>
+  using std::auto_ptr;
+#else
+#   include <memory>
+  template<typename T>
+    using auto_ptr = std::unique_ptr<T>;
+#endif
+
 template <class T> class simple_ptr
 {
 public:

stdcpp.h

@@ -16,7 +16,9 @@
 //   <memory>, auto_ptr and unique_ptr. Apple's built-in Clang behaves
 //   differently than a LLVM downloaded and compiled CLang. So we fall back to Clang's
 //   __has_include (http://clang.llvm.org/docs/LanguageExtensions.html#id3).
-#if (__cplusplus >= 201103L) && !defined(__clang__)
+// This must be kept in sync with smartptr.h because auto_ptr and unique_ptr are
+//   brought in based on the same logic.
+#if ((__cplusplus >= 201103L) || (_MSC_VER >= 1600)) && !defined(__clang__)
 #    include <memory>
 #elif defined(__clang__)
 #   if (__has_include(<tr1/memory>))