[libcxx-commits] [libcxx] [libc++] Don't claim strong emplace guarantee for vector/deque of throwing-move types (PR #229686)

[via libcxx-commits]

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+//===----------------------------------------------------------------------===//
+//
+// 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, c++17, c++20
+// UNSUPPORTED: no-exceptions
+
+// <flat_map>
+
+// Test that the invariants are restored when inserting an element in the middle of the
+// underlying containers throws from the element's assignment operator or, during
+// reallocation, from its copy constructor. Neither has a "no effects" guarantee for an
+// insertion in the middle of a vector or deque, even if the element type is
+// Cpp17CopyInsertable.
+
+#include <cassert>
+#include <deque>
+#include <flat_map>
+#include <functional>
+#include <type_traits>
+#include <vector>
+
+#include "test_macros.h"
+#include "../helpers.h"
+
+struct ThrowingAssign {
+  static inline bool throw_on_assign = false;
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huixie90 wrote:

I would avoid using global variables in the test which would require us to properly restore its state at every test point. What we usually do is to let the test class stores a reference to a local flag/variable and pass it through constructor argument. 

https://github.com/llvm/llvm-project/pull/229686