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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
// If we have a copy-propagating cache, when we copy ZeroOnDestroy, we will get a
// dangling reference to the copied-from object. This test ensures that we do not
// propagate the cache on copy.
#include <ranges>
#include <cstddef>
#include <cstring>
#include "test_macros.h"
#include "types.h"
struct ZeroOnDestroy : std::ranges::view_base {
unsigned count = 0;
int buff[8] = {1, 2, 3, 4, 5, 6, 7, 8};
constexpr ForwardIter begin() { return ForwardIter(buff); }
constexpr ForwardIter begin() const { return ForwardIter(); }
constexpr ForwardIter end() { return ForwardIter(buff + 8); }
constexpr ForwardIter end() const { return ForwardIter(); }
~ZeroOnDestroy() {
std::memset(buff, 0, sizeof(buff));
}
static auto dropFirstFour() {
ZeroOnDestroy zod;
std::ranges::drop_view dv(zod, 4);
// Make sure we call begin here so the next call to begin will
// use the cached iterator.
assert(*dv.begin() == 5);
// Intentionally invoke the copy ctor here.
return std::ranges::drop_view(dv);
}
};
int main(int, char**) {
auto noDanlingCache = ZeroOnDestroy::dropFirstFour();
// If we use the cached version, it will reference the copied-from view.
// Worst case this is a segfault, best case it's an assertion fired.
assert(*noDanlingCache.begin() == 5);
return 0;
}
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