std::experimental::unique_resource<R, D>::unique_resource

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Library fundamentals v3
 
std::experimental::unique_resource
 
unique_resource();
 (1) (library fundamentals TS v3)
template< class RR, class DD >
unique_resource( RR&& r, DD&& d ) noexcept(/*see below*/)
 (2) (library fundamentals TS v3)
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 resource 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

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