What is a ComPtr?
Creates a smart pointer type that represents the interface specified by the template parameter. ComPtr automatically maintains a reference count for the underlying interface pointer and releases the interface when the reference count goes to zero.
What is ComPtr in C++?
Microsoft::WRL::ComPtr is a C++ template smart-pointer for COM objects that is used extensively in Windows Runtime (WinRT) C++ programming. It works in Win32 desktop applications as well, and will work on Windows 7. Microsoft::WRL:::ComPtr is in the Windows 8.
How do you create a smart pointer in C++?
Declare the smart pointer as an automatic (local) variable. (Do not use the new or malloc expression on the smart pointer itself.) In the type parameter, specify the pointed-to type of the encapsulated pointer. Pass a raw pointer to a new -ed object in the smart pointer constructor.
What is DXGI device?
The IDXGIDevice interface is designed for use by DXGI objects that need access to other DXGI objects. This interface is useful to applications that do not use Direct3D to communicate with DXGI. The Direct3D create device functions return a Direct3D device object.
What is the use of IUnknown interface?
IUnknown interface (unknwn. Enables clients to get pointers to other interfaces on a given object through the QueryInterface method, and manage the existence of the object through the AddRef and Release methods.
What is __ Uuidof?
If you are using Microsoft Visual C++, you can avoid the need to link a static library by using the __uuidof operator. This operator is a Microsoft language extension. It returns a GUID value from an expression. The expression can be an interface type name, a class name, or an interface pointer.
Are pointers smart dogs?
They are alert and intelligent dogs who develop their instincts at a young age. Pointers are dedicated and loyal dogs. They enjoy the company of children and generally get along with other pets. Since they are such high-energy dogs, they need daily exercise, and obedience training is highly recommended.
What is the smart pointer in C++?
A Smart Pointer is a wrapper class over a pointer with an operator like * and -> overloaded. The objects of the smart pointer class look like normal pointers. But, unlike Normal Pointers it can deallocate and free destroyed object memory.
Where is IUnknown defined?
The IUnknown interface ID is defined as a GUID with the value of {00000000-0000-0000-C000-000000000046}. A COM component’s interfaces are required to exhibit the reflexive, symmetric, and transitive properties.
How does query interface work?
Because the object implements QueryInterface, it has the ability to accept or reject the request. If the object accepts the client’s request, QueryInterface returns a new pointer to the requested interface to the client. Through that interface pointer, the client has access to the methods of that interface.
What is __ Declspec?
The __declspec keyword enables you to specify special attributes of objects and functions. For example, you can use the __declspec keyword to declare imported or exported functions and variables, or to declare Thread Local Storage (TLS) objects. __declspec attributes are storage class modifiers.
What’s the difference between comptr and getaddressof?
This method differs from ComPtr::GetAddressOf in that this method releases a reference to the interface pointer. Use ComPtr::GetAddressOf when you require the address of the interface pointer but don’t want to release that interface. Retrieves a pointer to the type specified by the current template parameter.
How to release a reference from a comptr?
If you wish to release a reference from a particular ComPtr, you can use Reset() which sets the ComPtr to nullptr releasing any previous reference. ComPtr d3dDebug; d3dDebug.Reset(); d3dDebug = nullptr; has the same effect, but Reset is a bit more clear.
When does comptr release the underlying interface pointer?
ComPtr automatically maintains a reference count for the underlying interface pointer and releases the interface when the reference count goes to zero.
How does the comptr function in Microsoft Office work?
Returns a ComPtr object that represents the interface identified by the specified interface ID. Retrieves a weak reference to the current object. Associates this ComPtr with the interface type specified by the current template type parameter. Copies the current or specified interface associated with this ComPtr to the specified output pointer.