From 0f37a410293c8b507f51556eed5954d1a2fb0499 Mon Sep 17 00:00:00 2001
From: Marshall Clow <mclow.lists@gmail.com>
Date: Thu, 23 Mar 2017 13:43:37 +0000
Subject: [PATCH] Remove random_shuffle in C++17.  Please use shuffle instead.
 If you have to, you cant get it back by defining
 _LIBCPP_ENABLE_CXX17_REMOVED_RANDOM_SHUFFLE before including any libc++
 headers.

llvm-svn: 298597
---
 libcxx/include/algorithm                           |  6 ++-
 .../random_shuffle.cxx1z.pass.cpp                  | 46 ++++++++++++++++++++++
 .../alg.random.shuffle/random_shuffle.pass.cpp     |  1 +
 .../random_shuffle_rand.pass.cpp                   |  1 +
 4 files changed, 52 insertions(+), 2 deletions(-)
 create mode 100644 libcxx/test/libcxx/algorithms/alg.modifying.operations/alg.random.shuffle/random_shuffle.cxx1z.pass.cpp

diff --git a/libcxx/include/algorithm b/libcxx/include/algorithm
index 5eec80c..bba6d8d 100644
--- a/libcxx/include/algorithm
+++ b/libcxx/include/algorithm
@@ -281,12 +281,12 @@ template <class ForwardIterator, class OutputIterator>
 
 template <class RandomAccessIterator>
     void
-    random_shuffle(RandomAccessIterator first, RandomAccessIterator last); // deprecated in C++14
+    random_shuffle(RandomAccessIterator first, RandomAccessIterator last); // deprecated in C++14, removed in C++17
 
 template <class RandomAccessIterator, class RandomNumberGenerator>
     void
     random_shuffle(RandomAccessIterator first, RandomAccessIterator last,
-                   RandomNumberGenerator& rand);  // deprecated in C++14
+                   RandomNumberGenerator& rand);  // deprecated in C++14, removed in C++17
 
 template<class PopulationIterator, class SampleIterator,
          class Distance, class UniformRandomBitGenerator>
@@ -3026,6 +3026,7 @@ uniform_int_distribution<_IntType>::operator()(_URNG& __g, const param_type& __p
     return static_cast<result_type>(__u + __p.a());
 }
 
+#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_RANDOM_SHUFFLE)
 class _LIBCPP_TYPE_VIS __rs_default;
 
 _LIBCPP_FUNC_VIS __rs_default __rs_get();
@@ -3095,6 +3096,7 @@ random_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last,
         }
     }
 }
+#endif
 
 template <class _PopulationIterator, class _SampleIterator, class _Distance,
           class _UniformRandomNumberGenerator>
diff --git a/libcxx/test/libcxx/algorithms/alg.modifying.operations/alg.random.shuffle/random_shuffle.cxx1z.pass.cpp b/libcxx/test/libcxx/algorithms/alg.modifying.operations/alg.random.shuffle/random_shuffle.cxx1z.pass.cpp
new file mode 100644
index 0000000..8214e1e
--- /dev/null
+++ b/libcxx/test/libcxx/algorithms/alg.modifying.operations/alg.random.shuffle/random_shuffle.cxx1z.pass.cpp
@@ -0,0 +1,46 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <memory>
+
+// template <class RandomAccessIterator>
+//     void
+//     random_shuffle(RandomAccessIterator first, RandomAccessIterator last);
+// 
+// template <class RandomAccessIterator, class RandomNumberGenerator>
+//     void
+//     random_shuffle(RandomAccessIterator first, RandomAccessIterator last,
+//                    RandomNumberGenerator& rand);
+
+//
+//  In C++17, random_shuffle has been removed.
+//  However, for backwards compatibility, if _LIBCPP_ENABLE_CXX17_REMOVED_RANDOM_SHUFFLE
+//  is defined before including <algorithm>, then random_shuffle will be restored.
+
+#define _LIBCPP_ENABLE_CXX17_REMOVED_RANDOM_SHUFFLE
+
+#include <algorithm>
+#include <vector>
+
+struct gen
+{
+    std::ptrdiff_t operator()(std::ptrdiff_t n)
+    {
+        return n-1;
+    }
+};
+
+
+int main()
+{
+    std::vector<int> v;
+    std::random_shuffle(v.begin(), v.end());
+    gen r;
+    std::random_shuffle(v.begin(), v.end(), r);
+}
diff --git a/libcxx/test/std/algorithms/alg.modifying.operations/alg.random.shuffle/random_shuffle.pass.cpp b/libcxx/test/std/algorithms/alg.modifying.operations/alg.random.shuffle/random_shuffle.pass.cpp
index e24598a..77d7153 100644
--- a/libcxx/test/std/algorithms/alg.modifying.operations/alg.random.shuffle/random_shuffle.pass.cpp
+++ b/libcxx/test/std/algorithms/alg.modifying.operations/alg.random.shuffle/random_shuffle.pass.cpp
@@ -8,6 +8,7 @@
 //===----------------------------------------------------------------------===//
 
 // <algorithm>
+// REQUIRES-ANY: c++98, c++03, c++11, c++14
 
 // template<RandomAccessIterator Iter>
 //   requires ShuffleIterator<Iter>
diff --git a/libcxx/test/std/algorithms/alg.modifying.operations/alg.random.shuffle/random_shuffle_rand.pass.cpp b/libcxx/test/std/algorithms/alg.modifying.operations/alg.random.shuffle/random_shuffle_rand.pass.cpp
index c923d847..2424c77 100644
--- a/libcxx/test/std/algorithms/alg.modifying.operations/alg.random.shuffle/random_shuffle_rand.pass.cpp
+++ b/libcxx/test/std/algorithms/alg.modifying.operations/alg.random.shuffle/random_shuffle_rand.pass.cpp
@@ -8,6 +8,7 @@
 //===----------------------------------------------------------------------===//
 
 // <algorithm>
+// REQUIRES-ANY: c++98, c++03, c++11, c++14
 
 // template<RandomAccessIterator Iter, Callable<auto, Iter::difference_type> Rand>
 //   requires ShuffleIterator<Iter>
-- 
2.7.4