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The C and C++ Include Header Files

/usr/include/nodejs/deps/v8/include/cppgc/trace-trait.h


$ cat -n /usr/include/nodejs/deps/v8/include/cppgc/trace-trait.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_TRACE_TRAIT_H_
     6	#define INCLUDE_CPPGC_TRACE_TRAIT_H_
     7	
     8	#include <type_traits>
     9	
    10	#include "cppgc/type-traits.h"
    11	#include "v8config.h"  // NOLINT(build/include_directory)
    12	
    13	namespace cppgc {
    14	
    15	class Visitor;
    16	
    17	namespace internal {
    18	
    19	// Implementation of the default TraceTrait handling GarbageCollected and
    20	// GarbageCollectedMixin.
    21	template <typename T,
    22	          bool =
    23	              IsGarbageCollectedMixinTypeV<typename std::remove_const<T>::type>>
    24	struct TraceTraitImpl;
    25	
    26	}  // namespace internal
    27	
    28	/**
    29	 * Callback for invoking tracing on a given object.
    30	 *
    31	 * \param visitor The visitor to dispatch to.
    32	 * \param object The object to invoke tracing on.
    33	 */
    34	using TraceCallback = void (*)(Visitor* visitor, const void* object);
    35	
    36	/**
    37	 * Describes how to trace an object, i.e., how to visit all Oilpan-relevant
    38	 * fields of an object.
    39	 */
    40	struct TraceDescriptor {
    41	  /**
    42	   * Adjusted base pointer, i.e., the pointer to the class inheriting directly
    43	   * from GarbageCollected, of the object that is being traced.
    44	   */
    45	  const void* base_object_payload;
    46	  /**
    47	   * Callback for tracing the object.
    48	   */
    49	  TraceCallback callback;
    50	};
    51	
    52	namespace internal {
    53	
    54	struct V8_EXPORT TraceTraitFromInnerAddressImpl {
    55	  static TraceDescriptor GetTraceDescriptor(const void* address);
    56	};
    57	
    58	/**
    59	 * Trait specifying how the garbage collector processes an object of type T.
    60	 *
    61	 * Advanced users may override handling by creating a specialization for their
    62	 * type.
    63	 */
    64	template <typename T>
    65	struct TraceTraitBase {
    66	  static_assert(internal::IsTraceableV<T>, "T must have a Trace() method");
    67	
    68	  /**
    69	   * Accessor for retrieving a TraceDescriptor to process an object of type T.
    70	   *
    71	   * \param self The object to be processed.
    72	   * \returns a TraceDescriptor to process the object.
    73	   */
    74	  static TraceDescriptor GetTraceDescriptor(const void* self) {
    75	    return internal::TraceTraitImpl<T>::GetTraceDescriptor(
    76	        static_cast<const T*>(self));
    77	  }
    78	
    79	  /**
    80	   * Function invoking the tracing for an object of type T.
    81	   *
    82	   * \param visitor The visitor to dispatch to.
    83	   * \param self The object to invoke tracing on.
    84	   */
    85	  static void Trace(Visitor* visitor, const void* self) {
    86	    static_cast<const T*>(self)->Trace(visitor);
    87	  }
    88	};
    89	
    90	}  // namespace internal
    91	
    92	template <typename T>
    93	struct TraceTrait : public internal::TraceTraitBase<T> {};
    94	
    95	namespace internal {
    96	
    97	template <typename T>
    98	struct TraceTraitImpl<T, false> {
    99	  static_assert(IsGarbageCollectedTypeV<T>,
   100	                "T must be of type GarbageCollected or GarbageCollectedMixin");
   101	  static TraceDescriptor GetTraceDescriptor(const void* self) {
   102	    return {self, TraceTrait<T>::Trace};
   103	  }
   104	};
   105	
   106	template <typename T>
   107	struct TraceTraitImpl<T, true> {
   108	  static TraceDescriptor GetTraceDescriptor(const void* self) {
   109	    return internal::TraceTraitFromInnerAddressImpl::GetTraceDescriptor(self);
   110	  }
   111	};
   112	
   113	}  // namespace internal
   114	}  // namespace cppgc
   115	
   116	#endif  // INCLUDE_CPPGC_TRACE_TRAIT_H_