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winrt::handle_type struct template (C++/WinRT)

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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.

See also