winrt::handle_type struct template (C++/WinRT)
The template for the winrt::handle and winrt::file_handle structs, among others.
Note
You can define your own handle traits (see, for example, handle_traits or file_handle_traits in \cppwinrt\winrt\base.h), and use them with winrt::handle_type as typename T. Copy one of those examples from base.h into your own source code file, and provide your own handle type and implementation. There are more details in the MSDN Magazine article Windows with C++.
Syntax
template <typename T>
struct handle_type
Template parameters
typename T
A traits type that specifies the kind of handle being represented (a handle, a file handle, or some other type).
Requirements
Minimum supported SDK: Windows SDK version 10.0.17134.0 (Windows 10, version 1803)
Namespace: winrt
Header: %WindowsSdkDir%Include<WindowsTargetPlatformVersion>\cppwinrt\winrt\base.h (included by default)
Member type aliases
| Alias name | Type |
|---|---|
| handle_type::type | A synonym for typename T::type, where T is the typename T template parameter. |
Constructors
| Constructor | Description |
|---|---|
| handle_type::handle_type constructor | Initializes a new instance of the handle_type struct, optionally with a copy or move of the input data. |
Member functions
| Function | Description |
|---|---|
| handle_type::attach function | Attaches to a handle value, and takes ownership of it. |
| handle_type::close function | Closes the underlying handle. |
| handle_type::detach function | Detaches from the underlying handle. |
| handle_type::get function | Returns the underlying handle should you need to pass it to a function. |
| handle_type::put function | Returns the address of the underlying handle; this function helps you call methods that return references as out parameters via a pointer to a handle. |
Member operators
| Operator | Description |
|---|---|
| handle_type::operator bool | Checks whether or not the handle_type object currently represents a valid handle. |
| handle_type::operator= (assignment operator) | Assigns a value to the handle_type object. |
Free functions
| Function | Description |
|---|---|
| swap function | Swaps the contents of the two handle_type parameters so that they contain one another's handle. |
handle_type::handle_type constructor
Initializes a new instance of the handle_type struct, optionally with a copy or move of the input data.
Syntax
handle_type() noexcept;
explicit handle_type(handle_type::type value) noexcept;
handle_type(handle_type&& other) noexcept;
Parameters
value
A value that initializes the handle_type object.
other
Another handle_type that initializes the handle_type object.
handle_type::attach function
Attaches to a handle value, and takes ownership of it.
Syntax
void attach(handle_type::type value) noexcept;
Parameters
value
A handle value to attach to.
handle_type::close function
Closes the underlying handle.
Syntax
void close() noexcept;
handle_type::detach function
Detaches from the underlying handle.
Syntax
handle_type::type detach() noexcept;
Return value
The underlying handle formerly represented by the handle_type object.
handle_type::get function
Returns the underlying handle, should you need to pass it to a function.
Syntax
handle_type::type get() const noexcept;
Return value
The underlying handle represented by the handle_type object.
handle_type::put function
Returns the address of the underlying handle; this function helps you call methods that return references as out parameters via a pointer to a handle.
Syntax
handle_type::type* put() noexcept;
Return value
The address of the underlying handle represented by the handle_type object.
handle_type::operator bool
Checks whether or not the handle_type object currently represents a valid handle.
Syntax
explicit operator bool() const noexcept;
Return value
true if the handle_type object currently represents a valid handle, otherwise false.
handle_type::operator= (assignment operator)
Assigns a value to the handle_type object.
Syntax
winrt::handle_type& operator=(winrt::handle_type&& other) noexcept;
Parameters
other
A handle_type value to assign to the handle_type object.
Return value
A reference to the handle_type object.
swap function
Swaps the contents of the two handle_type parameters so that they contain one another's handle.
Syntax
void swap(winrt::handle_type& left, winrt::handle_type& right) noexcept;
Parameters
left right
A handle_type value whose handle to mutually swap with that of the other parameter.