Implement C++17 std::sample.

This patch implements the std::sample function added to C++17 from LFTS. It
also removes the std::experimental::sample implementation which now forwards
to std::sample.

llvm-svn: 279948

1 files changed, 41 insertions, 0 deletions

diff --git a/libcxx/test/std/algorithms/alg.modifying.operations/alg.random.sample/sample.fail.cpp b/libcxx/test/std/algorithms/alg.modifying.operations/alg.random.sample/sample.fail.cpp
new file mode 100644
index 00000000000..d769ad850c3
--- /dev/null
+++ b/libcxx/test/std/algorithms/alg.modifying.operations/alg.random.sample/sample.fail.cpp
@@ -0,0 +1,41 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+
+// <algorithm>
+
+// template <class PopulationIterator, class SampleIterator, class Distance,
+//           class UniformRandomNumberGenerator>
+// SampleIterator sample(PopulationIterator first, PopulationIterator last,
+//                       SampleIterator out, Distance n,
+//                       UniformRandomNumberGenerator &&g);
+
+#include <algorithm>
+#include <random>
+#include <cassert>
+
+#include "test_iterators.h"
+
+template <class PopulationIterator, class SampleIterator> void test() {
+  int ia[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+  const unsigned is = sizeof(ia) / sizeof(ia[0]);
+  const unsigned os = 4;
+  int oa[os];
+  std::minstd_rand g;
+  std::sample(PopulationIterator(ia), PopulationIterator(ia + is),
+                            SampleIterator(oa), os, g);
+}
+
+int main() {
+  // expected-error@algorithm:* {{static_assert failed "SampleIterator must meet the requirements of RandomAccessIterator"}}
+  // expected-error@algorithm:* 2 {{does not provide a subscript operator}}
+  // expected-error@algorithm:* {{invalid operands}}
+  test<input_iterator<int *>, output_iterator<int *> >();
+}