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#ifndef _LIBCPP___UTILITY_IS_POINTER_IN_RANGE_H
10#define _LIBCPP___UTILITY_IS_POINTER_IN_RANGE_H
11
12#include <__algorithm/comp.h>
13#include <__assert>
14#include <__config>
15#include <__type_traits/enable_if.h>
16#include <__type_traits/integral_constant.h>
17#include <__type_traits/is_constant_evaluated.h>
18#include <__type_traits/void_t.h>
19#include <__utility/declval.h>
20#include <__utility/is_valid_range.h>
21
22#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
23#  pragma GCC system_header
24#endif
25
26_LIBCPP_BEGIN_NAMESPACE_STD
27
28template <class _Tp, class _Up, class = void>
29struct __is_less_than_comparable : false_type {};
30
31template <class _Tp, class _Up>
32struct __is_less_than_comparable<_Tp, _Up, __void_t<decltype(std::declval<_Tp>() < std::declval<_Up>())> > : true_type {
33};
34
35template <class _Tp, class _Up, __enable_if_t<__is_less_than_comparable<const _Tp*, const _Up*>::value, int> = 0>
36_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI _LIBCPP_NO_SANITIZE("address") bool
37__is_pointer_in_range(const _Tp* __begin, const _Tp* __end, const _Up* __ptr) {
38  _LIBCPP_ASSERT_VALID_INPUT_RANGE(std::__is_valid_range(__begin, __end), "[__begin, __end) is not a valid range");
39
40  if (__libcpp_is_constant_evaluated()) {
41    // If this is not a constant during constant evaluation we know that __ptr is not part of the allocation where
42    // [__begin, __end) is.
43    if (!__builtin_constant_p(__begin <= __ptr && __ptr < __end))
44      return false;
45  }
46
47  return !__less<>()(__ptr, __begin) && __less<>()(__ptr, __end);
48}
49
50template <class _Tp, class _Up, __enable_if_t<!__is_less_than_comparable<const _Tp*, const _Up*>::value, int> = 0>
51_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI _LIBCPP_NO_SANITIZE("address") bool
52__is_pointer_in_range(const _Tp* __begin, const _Tp* __end, const _Up* __ptr) {
53  if (__libcpp_is_constant_evaluated())
54    return false;
55
56  return reinterpret_cast<const char*>(__begin) <= reinterpret_cast<const char*>(__ptr) &&
57         reinterpret_cast<const char*>(__ptr) < reinterpret_cast<const char*>(__end);
58}
59
60template <class _Tp, class _Up>
61_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool
62__is_overlapping_range(const _Tp* __begin, const _Tp* __end, const _Up* __begin2) {
63  auto __size = __end - __begin;
64  auto __end2 = __begin2 + __size;
65  return std::__is_pointer_in_range(__begin, __end, __begin2) || std::__is_pointer_in_range(__begin2, __end2, __begin);
66}
67
68_LIBCPP_END_NAMESPACE_STD
69
70#endif // _LIBCPP___UTILITY_IS_POINTER_IN_RANGE_H