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The C and C++ Include Header Files

/usr/include/nodejs/deps/v8/include/cppgc/garbage-collected.h


$ cat -n /usr/include/nodejs/deps/v8/include/cppgc/garbage-collected.h

     1	// Copyright 2020 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_GARBAGE_COLLECTED_H_
     6	#define INCLUDE_CPPGC_GARBAGE_COLLECTED_H_
     7	
     8	#include "cppgc/internal/api-constants.h"
     9	#include "cppgc/platform.h"
    10	#include "cppgc/trace-trait.h"
    11	#include "cppgc/type-traits.h"
    12	
    13	namespace cppgc {
    14	
    15	class Visitor;
    16	
    17	/**
    18	 * Base class for managed objects. Only descendent types of `GarbageCollected`
    19	 * can be constructed using `MakeGarbageCollected()`. Must be inherited from as
    20	 * left-most base class.
    21	 *
    22	 * Types inheriting from GarbageCollected must provide a method of
    23	 * signature `void Trace(cppgc::Visitor*) const` that dispatchs all managed
    24	 * pointers to the visitor and delegates to garbage-collected base classes.
    25	 * The method must be virtual if the type is not directly a child of
    26	 * GarbageCollected and marked as final.
    27	 *
    28	 * \code
    29	 * // Example using final class.
    30	 * class FinalType final : public GarbageCollected<FinalType> {
    31	 *  public:
    32	 *   void Trace(cppgc::Visitor* visitor) const {
    33	 *     // Dispatch using visitor->Trace(...);
    34	 *   }
    35	 * };
    36	 *
    37	 * // Example using non-final base class.
    38	 * class NonFinalBase : public GarbageCollected<NonFinalBase> {
    39	 *  public:
    40	 *   virtual void Trace(cppgc::Visitor*) const {}
    41	 * };
    42	 *
    43	 * class FinalChild final : public NonFinalBase {
    44	 *  public:
    45	 *   void Trace(cppgc::Visitor* visitor) const final {
    46	 *     // Dispatch using visitor->Trace(...);
    47	 *     NonFinalBase::Trace(visitor);
    48	 *   }
    49	 * };
    50	 * \endcode
    51	 */
    52	template <typename T>
    53	class GarbageCollected {
    54	 public:
    55	  using IsGarbageCollectedTypeMarker = void;
    56	  using ParentMostGarbageCollectedType = T;
    57	
    58	  // Must use MakeGarbageCollected.
    59	  void* operator new(size_t) = delete;
    60	  void* operator new[](size_t) = delete;
    61	  // The garbage collector is taking care of reclaiming the object. Also,
    62	  // virtual destructor requires an unambiguous, accessible 'operator delete'.
    63	  void operator delete(void*) {
    64	#ifdef V8_ENABLE_CHECKS
    65	    internal::Fatal(
    66	        "Manually deleting a garbage collected object is not allowed");
    67	#endif  // V8_ENABLE_CHECKS
    68	  }
    69	  void operator delete[](void*) = delete;
    70	
    71	 protected:
    72	  GarbageCollected() = default;
    73	};
    74	
    75	/**
    76	 * Base class for managed mixin objects. Such objects cannot be constructed
    77	 * directly but must be mixed into the inheritance hierarchy of a
    78	 * GarbageCollected object.
    79	 *
    80	 * Types inheriting from GarbageCollectedMixin must override a virtual method
    81	 * of signature `void Trace(cppgc::Visitor*) const` that dispatchs all managed
    82	 * pointers to the visitor and delegates to base classes.
    83	 *
    84	 * \code
    85	 * class Mixin : public GarbageCollectedMixin {
    86	 *  public:
    87	 *   void Trace(cppgc::Visitor* visitor) const override {
    88	 *     // Dispatch using visitor->Trace(...);
    89	 *   }
    90	 * };
    91	 * \endcode
    92	 */
    93	class GarbageCollectedMixin {
    94	 public:
    95	  using IsGarbageCollectedMixinTypeMarker = void;
    96	
    97	  /**
    98	   * This Trace method must be overriden by objects inheriting from
    99	   * GarbageCollectedMixin.
   100	   */
   101	  virtual void Trace(cppgc::Visitor*) const {}
   102	};
   103	
   104	}  // namespace cppgc
   105	
   106	#endif  // INCLUDE_CPPGC_GARBAGE_COLLECTED_H_