From ae0984b4b17e6bda2231da23c190033df369e5c0 Mon Sep 17 00:00:00 2001
From: Jeffrey Walton <noloader@gmail.com>
Date: Wed, 29 Jul 2015 13:37:52 -0400
Subject: [PATCH] Cleaned up tests for OS X, TR1 names spaces and ancient
 versus modern libstdc++ and libc++. Thanks to Jonathan Wakely for devising
 the clever test

---
 smartptr.h | 38 +++++++++++++++++++-------------------
 stdcpp.h   | 21 +++++----------------
 2 files changed, 24 insertions(+), 35 deletions(-)

diff --git a/smartptr.h b/smartptr.h
index 3ddfc9a9..30d996fa 100644
--- a/smartptr.h
+++ b/smartptr.h
@@ -7,26 +7,26 @@
 
 NAMESPACE_BEGIN(CryptoPP)
 
-#if 0
-// 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>;
+// Hack ahead. Apple's standard library does not have C++'s unique_ptr. We can't test
+// for unique_ptr directly because some of the Clangs on Apple fail the same way.
+// However, modern standard libraries have <forward_list>, so we test for it instead.
+// Thanks to Jonathan Wakely for devising the clever test for modern/ancient versions.
+
+#if (__cplusplus >= 201103L) || (_MSC_VER >= 1600)
+#    if defined(__clang__) && (__has_include(<forward_list>))
+#        define CRYPTOPP_HAVE_UNIQUE_PTR 1
+#    else
+#        define CRYPTOPP_HAVE_UNIQUE_PTR 1
+#    endif
+#endif
+
+#ifdef CRYPTOPP_HAVE_UNIQUE_PTR
+// use unique_ptr instead of auto_ptr
+template<typename T>
+    using std::auto_ptr = std::unique_ptr<T>;
+#else
+// do nothing; use auto_ptr
 #endif
-#endif // 0
 
 template <class T> class simple_ptr
 {
diff --git a/stdcpp.h b/stdcpp.h
index f5b62da6..517d1089 100644
--- a/stdcpp.h
+++ b/stdcpp.h
@@ -12,28 +12,17 @@
 #include <stdlib.h>
 #include <string.h>
 
-// http://marshall.calepin.co/c-and-xcode-46.html. Apple does some wonky stuff with
-//   <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).
-// 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>))
-#      include <tr1/memory>
-#   endif
-#elif (__cplusplus < 201103L)
-#   include <tr1/memory>
-#else
-#   include <memory>
+// http://marshall.calepin.co/c-and-xcode-46.html.
+// This include is needed so we can pickup _LIBCPP_VERSION, if needed.
+#if defined(__APPLE__)
+# include <ciso646>
 #endif
 
 #include <map>
 #include <vector>
 #include <string>
 #include <limits>
+#include <memory>
 #include <exception>
 #include <typeinfo>
 #include <algorithm>