[libcxx-commits] [libcxx] [libc++][PSTL] Implement std::equal (PR #72448)

[Louis Dionne via libcxx-commits]

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@@ -0,0 +1,98 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+
+// UNSUPPORETD: libcpp-has-no-incomplete-pstl
+
+// <algorithm>
+
+// template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2>
+//   bool equal(ExecutionPolicy&& exec,
+//              ForwardIterator1 first1, ForwardIterator1 last1,
+//              ForwardIterator2 first2);
+//
+// template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
+//          class BinaryPredicate>
+//   bool equal(ExecutionPolicy&& exec,
+//              ForwardIterator1 first1, ForwardIterator1 last1,
+//              ForwardIterator2 first2, BinaryPredicate pred);
+//
+// template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2>
+//   bool equal(ExecutionPolicy&& exec,
+//              ForwardIterator1 first1, ForwardIterator1 last1,
+//              ForwardIterator2 first2, ForwardIterator2 last2);
+//
+// template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
+//          class BinaryPredicate>
+//   bool equal(ExecutionPolicy&& exec,
+//              ForwardIterator1 first1, ForwardIterator1 last1,
+//              ForwardIterator2 first2, ForwardIterator2 last2,
+//              BinaryPredicate pred);
+
+#include <algorithm>
+#include <cassert>
+
+#include "test_execution_policies.h"
+#include "test_iterators.h"
+#include "test_macros.h"
+
+template <class Iter1, class Iter2>
+struct Test {
+  template <class Policy>
+  void operator()(Policy&& policy) {
+    { // 3 iter overloads
+      int a[] = {1, 2, 3, 4, 5, 6, 7, 8};
+      int b[] = {1, 2, 3, 5, 6, 7, 8, 9};
+
+      // simple test
+      assert(std::equal(policy, Iter1(std::begin(a)), Iter1(std::end(a)), Iter2(std::begin(a))));
+
+      // check that false is returned on different ranges
+      assert(!std::equal(policy, Iter1(std::begin(a)), Iter1(std::end(a)), Iter2(std::begin(b))));
+
+      // check that the predicate is used
+      assert(std::equal(policy, Iter1(std::begin(a)), Iter1(std::end(a)), Iter2(std::begin(b)), [](int lhs, int rhs) {
----------------
ldionne wrote:

Why don't you just do this:

```
[](int lhs, int rhs) { return lhs % 2 == rhs % 2; };
```

Then you need to call that with two ranges that are not equal, but where all the elements have the same odd-ness.

https://github.com/llvm/llvm-project/pull/72448