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The C and C++ Include Header Files

cat -n /usr/include/node/cppgc/sentinel-pointer.h

     1	// Copyright 2021 the V8 project authors. All rights reserved.
     2	// Use of this source code is governed by a BSD-style license that can be
     3	// found in the LICENSE file.
     4	
     5	#ifndef INCLUDE_CPPGC_SENTINEL_POINTER_H_
     6	#define INCLUDE_CPPGC_SENTINEL_POINTER_H_
     7	
     8	#include <cstdint>
     9	
    10	#include "cppgc/internal/api-constants.h"
    11	
    12	namespace cppgc {
    13	namespace internal {
    14	
    15	// Special tag type used to denote some sentinel member. The semantics of the
    16	// sentinel is defined by the embedder.
    17	struct SentinelPointer {
    18	#if defined(CPPGC_POINTER_COMPRESSION)
    19	  static constexpr intptr_t kSentinelValue =
    20	      1 << api_constants::kPointerCompressionShift;
    21	#else   // !defined(CPPGC_POINTER_COMPRESSION)
    22	  static constexpr intptr_t kSentinelValue = 0b10;
    23	#endif  // !defined(CPPGC_POINTER_COMPRESSION)
    24	  template <typename T>
    25	  operator T*() const {
    26	    return reinterpret_cast<T*>(kSentinelValue);
    27	  }
    28	  // Hidden friends.
    29	  friend bool operator==(SentinelPointer, SentinelPointer) { return true; }
    30	  friend bool operator!=(SentinelPointer, SentinelPointer) { return false; }
    31	};
    32	
    33	}  // namespace internal
    34	
    35	constexpr internal::SentinelPointer kSentinelPointer;
    36	
    37	}  // namespace cppgc
    38	
    39	#endif  // INCLUDE_CPPGC_SENTINEL_POINTER_H_