Defined in header <experimental/scope>
template<class R, class D>
class unique_resource;
(library fundamentals TS v3)

unique_resource is universal RAII wrapper for resource handles that owns and manages a resource through a handle and disposes of that resource when the unique_resource is destroyed.

The resource is disposed of using the deleter of type D when either of the following happens:

  • the managing unique_resource object is destroyed
  • the managing unique_resource object is assigned from another resource via operator= or reset().

Let type RS be R if R is an object type, or std::reference_wrapper<std::remove_reference_t<R>> otherwise:

  • unique_resource effectively holds a subobject of type RS which is or wraps the resource handle, a deleter of type D and a bool flag indicating whether the wrapper is owning the resource.
  • For explanatory purpose, the subobject of type RS is called stored resource handle, and the stored (if R is an object type) or wrapped (if R is a reference type) R is called underlying resource handle. These two terms are not used by the LFTS.


[edit] Template parameters

R - resource handle type
D - deleter type
Type requirements
R shall be an object type or an lvalue reference to an object type. Let UnrefR be std::remove_reference_t<R>, UnrefR shall be MoveConstructible, and if UnrefR is not CopyConstructible, std::is_nothrow_move_constructible_v<UnrefR> shall be true.
D shall be a Destructible and MoveConstructible FunctionObject type, and if D is not CopyConstructible, std::is_nothrow_move_constructible_v<D> shall be true. Given an lvalue d of type D and an lvalue r of type UnrefR, the expression d(r) shall be well-formed.

[edit] Member functions

constructs a new unique_resource
(public member function) [edit]
disposes the managed resource if such is present
(public member function) [edit]
assigns a unique_resource
(public member function) [edit]
releases the ownership
(public member function) [edit]
disposes or replaces the managed resource
(public member function) [edit]
accesses the underlying resource handle
(public member function) [edit]
accesses the deleter used for disposing of the managed resource
(public member function) [edit]
accesses the pointee if the resource handle is a pointer
(public member function) [edit]

[edit] Non-member functions

creates a unique_resource, checking invalid value
(function template) [edit]

[edit] Deduction guides

[edit] Notes

Resource handle types satisfying NullablePointer can also be managed by std::unique_ptr. Unlike unique_ptr, unique_resource does not require NullablePointer.

[edit] Example

[edit] See also

smart pointer with unique object ownership semantics
(class template) [edit]