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std::experimental::unique_resource::unique_resource(3) C++ Standard Libary std::experimental::unique_resource::unique_resource(3)

NAME

std::experimental::unique_resource::unique_resource - std::experimental::unique_resource::unique_resource

Synopsis


unique_resource(); (1) (library fundamentals TS v3)
template <class RR, class DD>
unique_resource( RR&& r, DD&& d ) noexcept(/*see (2) (library fundamentals TS v3)
below*/)
unique_resource( unique_resource&& other ); (3) (library fundamentals TS v3)


Follow items are used for explanatory purpose:


* RS is the type of stored resource handle.
* The expression res_ refers the underlying resource handle.
* del_ refers the deleter object.


1) Default constructor. Value-initializes the stored resource handle and the
deleter. The constructed unique_resource does not own the resource.
This overload participates in overload resolution only if both
std::is_default_constructible_v<R> and std::is_default_constructible_v<D> are true.
2) The stored resource handle is initialized with std::forward<RR>(r) if
std::is_nothrow_constructible_v<RS, RR> is true, otherwise r. If initialization of
the stored resource handle throws an exception, calls d(r).
Then, the deleter is initialized with std::forward<DD>(d) if
std::is_nothrow_constructible_v<D, DD> is true, otherwise d. If initialization of
deleter throws an exception, calls d(res_).
The constructed unique_resource owns the resource.
This overload participates in overload resolution only if all of
std::is_constructible_v<RS, RR>, std::is_constructible_v<D , DD>,
std::is_nothrow_constructible_v<RS, RR> || std::is_constructible_v<RS, RR&> and
std::is_nothrow_constructible_v<D, DD> || std::is_constructible_v<D, DD&> are true.
The program is ill-formed if any of the expressions d(r), d(res_) and del_(res_) is
ill-formed.
The behavior is undefined if any of the expressions d(r), d(res_) and del_(res_)
results in undefined behavior or throws an exception.
3) Move constructor. The stored resource handle is initialized from the one of
other, using std::move if std::is_nothrow_move_constructible_v<RS> is true. If
initialization of the stored resource handle throws an exception, other is not
modified.
Then, the deleter is initialized with the one of other, using std::move if
std::is_nothrow_move_constructible_v<D> is true. If initialization of the deleter
throws an exception and std::is_nothrow_move_constructible_v<RS> is true and other
owns the resource, calls the deleter of other with res_ to dispose the resource,
then calls other.release().
After construction, the constructed unique_resource owns its resource if and only if
other owned the resource before the construction, and other is set to not own the
resource.

Parameters


r - a resouce handle
d - a deleter to use to dispose the resource
other - another unique_resource to acquire the ownership from

Exceptions


Any exception thrown during initialization of the stored resource handle or the
deleter.


2)
noexcept specification:
noexcept((


std::is_nothrow_constructible_v<RS, RR> || std::is_nothrow_constructible_v<RS, RR&>
) &&
(
std::is_nothrow_constructible_v<D, DD> || std::is_nothrow_constructible_v<D, DD&>


))
3)
noexcept specification:
noexcept(


std::is_nothrow_move_constructible_v<R1> && std::is_nothrow_move_constructible_v<D>


)

Notes


The mechanism of these constructors ensures no leaking of resources.

Example


This section is incomplete
Reason: no example

See also


constructor constructs a new unique_ptr
(public member function of std::unique_ptr<T,Deleter>)

2022.07.31 http://cppreference.com