llvm-project/libcxx/include/__algorithm/ranges_find_if_not.h
Louis Dionne 02540b2f6d
[libc++] Make sure ranges algorithms and views handle boolean-testable correctly (#69378)
Before this patch, we would fail to implicitly convert the result of
predicates to bool, which means we'd potentially perform a copy or move
construction of the boolean-testable, which isn't allowed. The same
holds true for comparing iterators against sentinels, which is allowed
to return a boolean-testable type.

We already had tests aiming to ensure correct handling of these types,
but they failed to provide appropriate coverage in several cases due to
guaranteed RVO. This patch fixes the tests, adds tests for missing
algorithms and views, and fixes the actual problems in the code.

Fixes #69074
2023-11-06 21:19:49 -10:00

65 lines
2.3 KiB
C++

//===----------------------------------------------------------------------===//
//
// 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 _LIBCPP___ALGORITHM_RANGES_FIND_IF_NOT_H
#define _LIBCPP___ALGORITHM_RANGES_FIND_IF_NOT_H
#include <__algorithm/ranges_find_if.h>
#include <__config>
#include <__functional/identity.h>
#include <__functional/invoke.h>
#include <__functional/ranges_operations.h>
#include <__iterator/concepts.h>
#include <__iterator/projected.h>
#include <__ranges/access.h>
#include <__ranges/concepts.h>
#include <__ranges/dangling.h>
#include <__utility/forward.h>
#include <__utility/move.h>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
#if _LIBCPP_STD_VER >= 20
_LIBCPP_BEGIN_NAMESPACE_STD
namespace ranges {
namespace __find_if_not {
struct __fn {
template <input_iterator _Ip,
sentinel_for<_Ip> _Sp,
class _Proj = identity,
indirect_unary_predicate<projected<_Ip, _Proj>> _Pred>
_LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr _Ip
operator()(_Ip __first, _Sp __last, _Pred __pred, _Proj __proj = {}) const {
auto __pred2 = [&](auto&& __e) -> bool { return !std::invoke(__pred, std::forward<decltype(__e)>(__e)); };
return ranges::__find_if_impl(std::move(__first), std::move(__last), __pred2, __proj);
}
template <input_range _Rp, class _Proj = identity, indirect_unary_predicate<projected<iterator_t<_Rp>, _Proj>> _Pred>
_LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr borrowed_iterator_t<_Rp>
operator()(_Rp&& __r, _Pred __pred, _Proj __proj = {}) const {
auto __pred2 = [&](auto&& __e) -> bool { return !std::invoke(__pred, std::forward<decltype(__e)>(__e)); };
return ranges::__find_if_impl(ranges::begin(__r), ranges::end(__r), __pred2, __proj);
}
};
} // namespace __find_if_not
inline namespace __cpo {
inline constexpr auto find_if_not = __find_if_not::__fn{};
} // namespace __cpo
} // namespace ranges
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP_STD_VER >= 20
#endif // _LIBCPP___ALGORITHM_RANGES_FIND_IF_NOT_H