#include <baseref.h>

Inheritance diagram for BaseRef< T, HANDLER >:

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详细描述

template<typename T, typename HANDLER>
class maxon::BaseRef< T, HANDLER >

This is a general template for references of any kind. The characteristic feature of it is that special actions are triggered whenever the reference is set, cleared, changed or destructed. For example, a reference to a reference-counted object has to increase the reference count of the pointee when the pointer is set, and to decrease the count when the reference is cleared. Another example of reference is a unique reference which simply frees the pointee when it is cleared or destructed.

BaseRef delegates the specific behaviour to static members of the template parameter HANDLER. There are several implementations available to be used as HANDLER:

• StrongRefHandler is used for objects which have a reference counter (used by StrongRef).
• StrongCOWRefHandler has an additional copy-on-write semantics. I.e., if the pointee is referenced more than once, a copy is made before the pointee is modified through the BaseRef (used by StrongCOWRef).
• UniqueRefHandler uses DeleteObj to release the memory, so the object's destructor is invoked (used by UniqueRef).
• PointerHandler lets the BaseRef behave like an ordinary C++ pointer, so nothing is done when the pointer is changed (used by Pointer).

So if you want to have a reference to an object of type MyType with reference counting and copy-on-write semantics, you could use BaseRef<const MyType, StrongCOWRefHandler> which is equivalent to StrongCOWRef<MyType>.

Template Parameters

T	Type of the referenced object.
HANDLER	Base class for BaseRef . This implements the specific behaviour whenever a reference is changed to point to another object, see above.

注意

BaseRef is neither atomic nor thread-safe. .

• After a BaseRef is guaranteed not to change anymore multiple threads can safely read from it concurrently.
• Reading and writing on the same BaseRef from different threads will crash (the reference to an object might have been released by a writing thread before a reading thread was able to add a reference).
• Writing to the same BaseRef from different threads will also crash because this implies a read operation (a write has to read the old value to release the reference to the previous object).
• If you really have to read and write from multiple threads you could use the ThreadSafeRef class.

Member Typedef Documentation

◆  ReferencedType

A type alias for the type the BaseRef points to.

◆  ConstReferencedType

◆  DirectlyReferencedType

◆  SelfType

◆  IsGenericBaseOf

◆  Handler

◆  RefCompareType

构造函数 & 析构函数文档编制

◆  BaseRef() [1/10]

◆  BaseRef() [2/10]

◆  BaseRef() [3/10]

Constructs a BaseRef , initializing the pointer with the given argument.

参数

[in]

o

Pointer with which the BaseRef is initialized, may be nullptr.

◆  BaseRef() [4/10]

Constructs a BaseRef with a pointer forwarded from a memory allocation. The template parameter is used to avoid unnecessary conversion from ResultPtr<X> to ResultPtr<const X>.

参数

[in]

o

Pointer with which the BaseRef is initialized, may be nullptr on OutOfMemory.

◆  BaseRef() [5/10]

Constructs a BaseRef with a pointer forwarded from a memory allocation. To prevent accidental assignment from an allocation without error handling a dummy parameter has to be passed as well.

参数

[in]

o

Pointer with which the BaseRef is initialized, may be nullptr on OutOfMemory.

◆  BaseRef() [6/10]

Constructs a BaseRef , initializing the pointer with the pointer of another BaseRef .

参数

[in]

src

Another BaseRef whose internal pointer will be used to initialize this BaseRef .

◆  BaseRef() [7/10]

Constructs a BaseRef , initializing the pointer with the pointer of another reference object.

参数

[in]

src

A reference object whose internal pointer will be used to initialize this BaseRef .

◆  BaseRef() [8/10]

◆  BaseRef() [9/10]

Constructs a new BaseRef by moving the pointer from src to this. The pointer of src will be a nullptr afterwards.

参数

[in]

src

Another BaseRef for the move.

◆  BaseRef() [10/10]

Constructs a new BaseRef by moving the pointer from src to this. The pointer of src will be a nullptr afterwards.

参数

[in]

src

Another BaseRef for the move.

◆  ~BaseRef()

Destructs this BaseRef , including proper release of the reference.

成员函数文档编制

◆  GenericVarianceCheck()

◆  GetPointer() [1/2]

Returns the internal pointer of the BaseRef . You can also use operator-> to access members of the pointee directly through the BaseRef .

返回

Internal pointer.

◆  GetPointer() [2/2]

Returns the internal pointer of the BaseRef . You can also use operator-> to access members of the pointee directly through the BaseRef .

返回

Internal pointer.

◆  operator->() [1/2]

Allows direct access to the members of the pointee. You have to check for a nullptr before.

返回

Internal pointer.

◆  operator->() [2/2]

Allows direct access to the members of the pointee. You have to check for a nullptr before.

返回

Internal pointer.

◆  operator*() [1/2]

Dereferences the BaseRef . This yields the pointee as a reference. You have to check for a nullptr before.

返回

Pointee as a reference.

◆  operator*() [2/2]

Dereferences the BaseRef . This yields the pointee as a reference. You have to check for a nullptr before.

返回

Pointee as a reference.

◆  operator T*()

User-defined conversion to T*, unpacking the internal pointer.

返回

Internal pointer.

◆  operator ConstReferencedType *()

User-defined conversion to T*, unpacking the internal pointer.

返回

Internal pointer.

◆  operator Bool() [1/2]

Checks if the pointer is valid (i.e., not a nullptr).

返回

True if the internal pointer is not a nullptr.

◆  operator Bool() [2/2]

◆  operator[]()

◆  MakeWritable()

Makes the pointee writable. Depending on the argument for the template parameter HANDLER, this may just return the original pointer, or it may replace the pointer by a new one pointing to a copy of the original pointee, and return the new pointer. The latter is the case for copy-on-write semantics if there is more than one reference to the pointee.

参数

[in]

resetOnError

If true (the default), the reference will be reset when the copy fails. If false, the reference will stay the same, but the function returns nullptr.

返回

Internal pointer, which might be a new pointer pointing to a copy of the original pointee, or nullptr if the copy failed.

◆  GetOrNull()

◆  Create()

Creates the referenced type.

参数

[in]

args

Arguments for the construcor.

Template Parameters

ARGS	Parameter types.

返回

OK on success, FAILED only for OutOfMemoryerror.

◆  operator=() [1/7]

Lets the BaseRef point to another object. This performs the necessary operations for removing the reference to the current pointee and adding the reference to the new pointee.

参数

[in]

src

New pointer, may be nullptr.

◆  operator=() [2/7]

Resets the internal pointer to nullptr, which includes the proper release of the reference.

◆  operator=() [3/7]

Lets the BaseRef point to the object of another BaseRef . This performs the necessary operations for removing the reference to the current pointee and adding the reference to the new pointee.

参数

[in]

src

BaseRef of which the pointer will be used.

◆  operator=() [4/7]

Lets the BaseRef point to the object of another reference object. This performs the necessary operations for removing the reference to the current pointee and adding the reference to the new pointee.

参数

[in]

src

Another reference of which the pointer will be used.

◆  operator=() [5/7]

◆  operator=() [6/7]

Moves the internal pointer from src to this. src will be a nullptr reference afterwards.

参数

[in]

src

BaseRef whose internal pointer shall be moved to this BaseRef .

◆  operator=() [7/7]

Moves the internal pointer from src to this. src will be a nullptr reference afterwards. Moves from BaseRef with different HANDLER as well as interface references.

参数

[in]

src

BaseRef whose internal pointer shall be moved to this BaseRef .

◆  operator==() [1/4]

Returns true when this and b are equal as determined by RefCompare .

参数

[in]

b

Reference to compare with.

返回

True when this and b are equal, false otherwise.

◆  operator!=() [1/4]

Returns true when this and b are not equal as determined by RefCompare .

参数

[in]

b

Reference to compare with.

返回

True when this and b are not equal, false otherwise.

◆  operator==() [2/4]

Returns true when this and b are equal as determined by RefCompare .

参数

[in]

b

Pointer to compare with.

返回

True when this and b are equal, false otherwise.

◆  operator!=() [2/4]

Returns true when this and b are not equal as determined by RefCompare .

参数

[in]

b

Reference to compare with.

返回

True when this and b are not equal, false otherwise.

◆  operator==() [3/4]

Returns true when this and b are equal as determined by RefCompare .

参数

[in]

b

Pointer to compare with.

返回

True when this and b are equal, false otherwise.

◆  operator!=() [3/4]

Returns true when this and b are not equal as determined by RefCompare .

参数

[in]

b

Reference to compare with.

返回

True when this and b are not equal, false otherwise.

◆  operator==() [4/4]

Returns true when this and a null reference are equal as determined by RefCompare .

返回

True when this and nullptr are equal, false otherwise.

◆  operator!=() [4/4]

Returns true when this and a null reference are not equal as determined by RefCompare .

返回

True when this and nullptr are not equal, false otherwise.

◆  GetHashCode()

Returns the hash code of the reference, see RefCompare .

返回

The reference's hash code.

◆  NullValueRef()

◆  NullValue()

◆  Disconnect()

Sets the internal pointer to nullptr and returns its previous value. This moves the ownership of the object from this UniqueRef to the invoking code, so you have to take care of proper deallocation once the object isn't needed any longer.

◆  PrivateSetTarget()

Lets the BaseRef point to another freshly allocated object. This performs the necessary operations for removing the reference to the current pointee and adding the reference to the new pointee.

参数

[in]

src

New pointer, may be nullptr.

◆  PrivateSetPointer()

◆  operator+()

◆  operator-() [1/2]

◆  operator-() [2/2]

◆  PrivateNullValue() [1/2]

◆  PrivateNullValue() [2/2]

Friends And Related Function Documentation

◆  BaseRef

Member Data Documentation

◆  DIRECT_REF

◆  _object

• maxon
• BaseRef