[libcxx-commits] [libcxx] [libc++] Simplify vector<bool>::flip() and add new tests (PR #119607)

[Nikolas Klauser via libcxx-commits]

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@@ -0,0 +1,100 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// <vector>
+
+// void flip();
+
+#include <cassert>
+#include <vector>
+
+#include "min_allocator.h"
+#include "test_allocator.h"
+#include "test_macros.h"
+
+TEST_CONSTEXPR_CXX20 bool tests() {
+  //
+  // Testing flip() function with small vectors and various allocators
+  //
+  {
+    std::vector<bool> v;
+    v.push_back(true);
+    v.push_back(false);
+    v.push_back(true);
+    v.flip();
+    assert(!v[0]);
+    assert(v[1]);
+    assert(!v[2]);
+  }
+  {
+    std::vector<bool, min_allocator<bool> > v;
+    v.push_back(true);
+    v.push_back(false);
+    v.push_back(true);
+    v.flip();
+    assert(!v[0]);
+    assert(v[1]);
+    assert(!v[2]);
+  }
+  {
+    std::vector<bool, test_allocator<bool> > v(test_allocator<bool>(5));
+    v.push_back(true);
+    v.push_back(false);
+    v.push_back(true);
+    v.flip();
+    assert(!v[0]);
+    assert(v[1]);
+    assert(!v[2]);
+  }
+
+  //
+  // Testing flip() function with larger vectors
+  //
+  {
+    std::vector<bool> v(1000);
+    for (std::size_t i = 0; i < v.size(); ++i)
+      v[i] = i & 1;
+    std::vector<bool> original = v;
+    v.flip();
+    for (size_t i = 0; i < v.size(); ++i) {
+      assert(v[i] == !original[i]);
+    }
+  }
+  {
+    std::vector<bool, min_allocator<bool> > v(1000, false, min_allocator<bool>());
+    for (std::size_t i = 0; i < v.size(); ++i)
+      v[i] = i & 1;
+    std::vector<bool, min_allocator<bool> > original = v;
+    v.flip();
+    for (size_t i = 0; i < v.size(); ++i)
+      assert(v[i] == !original[i]);
+    v.flip();
+    assert(v == original);
+  }
+  {
+    std::vector<bool, test_allocator<bool> > v(1000, false, test_allocator<bool>(5));
+    for (std::size_t i = 0; i < v.size(); ++i)
+      v[i] = i & 1;
+    std::vector<bool, test_allocator<bool> > original = v;
+    v.flip();
+    for (size_t i = 0; i < v.size(); ++i)
+      assert(v[i] == !original[i]);
+    v.flip();
+    assert(v == original);
+  }
+
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER > 17
----------------
philnik777 wrote:

```suggestion
#if TEST_STD_VER >= 20
```

https://github.com/llvm/llvm-project/pull/119607