1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 // <vector>
10 
11 // void push_back(const value_type& x);
12 //
13 // If no reallocation happens, then references, pointers, and iterators before
14 // the insertion point remain valid but those at or after the insertion point,
15 // including the past-the-end iterator, are invalidated.
16 
17 // REQUIRES: has-unix-headers, libcpp-has-abi-bounded-iterators-in-vector
18 // UNSUPPORTED: c++03
19 // UNSUPPORTED: libcpp-hardening-mode=none
20 // XFAIL: libcpp-hardening-mode=debug && availability-verbose_abort-missing
21 
22 #include <vector>
23 #include <cassert>
24 #include <cstddef>
25 
26 #include "check_assertion.h"
27 
28 int main(int, char**) {
29   std::vector<int> vec;
30   vec.reserve(4);
31   std::size_t old_capacity = vec.capacity();
32   assert(old_capacity >= 4);
33 
34   vec.push_back(0);
35   vec.push_back(1);
36   vec.push_back(2);
37   auto it = vec.begin();
38   vec.push_back(3);
39   assert(vec.capacity() == old_capacity);
40 
41   // The capacity did not change, so the iterator remains valid and can reach the new element.
42   assert(*it == 0);
43   assert(*(it + 1) == 1);
44   assert(*(it + 2) == 2);
45   assert(*(it + 3) == 3);
46 
47   while (vec.capacity() == old_capacity) {
48     vec.push_back(42);
49   }
50   TEST_LIBCPP_ASSERT_FAILURE(
51       *(it + old_capacity), "__bounded_iter::operator*: Attempt to dereference an iterator at the end");
52   // Unfortunately, the bounded iterator does not detect that it's been invalidated and will still allow attempts to
53   // dereference elements 0 to 3 (even though they refer to memory that's been reallocated).
54 
55   return 0;
56 }
57