[libcxx-commits] [libcxx] [libc++] Add exception guard for vector<bool>::__init_with_sentinel (PR #115491)

[Louis Dionne via libcxx-commits]

================
@@ -0,0 +1,87 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef EXCEPTION_TEST_HELPERS_H
+#define EXCEPTION_TEST_HELPERS_H
+
+#include "count_new.h"
+
+template <class T>
+struct throwing_allocator {
+  using value_type      = T;
+  using is_always_equal = std::false_type;
+
+  bool throw_on_copy_ = false;
+
+  throwing_allocator(bool throw_on_ctor = true, bool throw_on_copy = false) : throw_on_copy_(throw_on_copy) {
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ldionne wrote:

```suggestion
  explicit throwing_allocator(bool throw_on_ctor, bool throw_on_copy) : throw_on_copy_(throw_on_copy) {
```

Let's remove the defaults. When we construct, let's use `throwing_allocator alloc(/* throw_on_ctor */true, /* throw_on_copy */false);` (for example), to make this more explicit.

https://github.com/llvm/llvm-project/pull/115491