Abseil Common Libraries (C++) (grcp 依赖)
https://abseil.io/
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
49 lines
1.7 KiB
49 lines
1.7 KiB
// Copyright 2018 The Abseil Authors. |
|
// |
|
// Licensed under the Apache License, Version 2.0 (the "License"); |
|
// you may not use this file except in compliance with the License. |
|
// You may obtain a copy of the License at |
|
// |
|
// http://www.apache.org/licenses/LICENSE-2.0 |
|
// |
|
// Unless required by applicable law or agreed to in writing, software |
|
// distributed under the License is distributed on an "AS IS" BASIS, |
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
|
// See the License for the specific language governing permissions and |
|
// limitations under the License. |
|
|
|
#ifndef ABSL_BASE_INTERNAL_HIDE_PTR_H_ |
|
#define ABSL_BASE_INTERNAL_HIDE_PTR_H_ |
|
|
|
#include <cstdint> |
|
|
|
namespace absl { |
|
namespace base_internal { |
|
|
|
// Arbitrary value with high bits set. Xor'ing with it is unlikely |
|
// to map one valid pointer to another valid pointer. |
|
constexpr uintptr_t HideMask() { |
|
static_assert(sizeof(uintptr_t) == 4 || sizeof(uintptr_t) == 8, |
|
"uintptr_t must be 32 or 64 bits"); |
|
return sizeof(uintptr_t) == 8 ? 0xF03A5F7BF03A5F7BULL : 0xF03A5F7BUL; |
|
} |
|
|
|
// Hide a pointer from the leak checker. For internal use only. |
|
// Differs from absl::IgnoreLeak(ptr) in that absl::IgnoreLeak(ptr) causes ptr |
|
// and all objects reachable from ptr to be ignored by the leak checker. |
|
template <class T> |
|
inline uintptr_t HidePtr(T* ptr) { |
|
return reinterpret_cast<uintptr_t>(ptr) ^ HideMask(); |
|
} |
|
|
|
// Return a pointer that has been hidden from the leak checker. |
|
// For internal use only. |
|
template <class T> |
|
inline T* UnhidePtr(uintptr_t hidden) { |
|
return reinterpret_cast<T*>(hidden ^ HideMask()); |
|
} |
|
|
|
} // namespace base_internal |
|
} // namespace absl |
|
|
|
#endif // ABSL_BASE_INTERNAL_HIDE_PTR_H_
|
|
|