std::experimental::unique_resource
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< cpp | experimental
| Defined in header <experimental/scope>
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| 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_resourceobject is destroyed, - the managing
unique_resourceobject 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_resourceeffectively holds a subobject of typeRSwhich is or wraps the resource handle, a deleter of typeDand a bool flag indicating whether the wrapper is owning the resource. - For explanatory purpose, the subobject of type
RSis called stored resource handle, and the stored (ifRis an object type) or wrapped (ifRis a reference type)Ris called underlying resource handle. These two terms are not used by the LFTS.
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.
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-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.
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Member functions
constructs a new unique_resource (public member function) | |
| disposes the managed resource if such is present (public member function) | |
assigns a unique_resource (public member function) | |
Modifiers | |
| releases the ownership (public member function) | |
| disposes or replaces the managed resource (public member function) | |
Observers | |
| accesses the underlying resource handle (public member function) | |
| accesses the deleter used for disposing of the managed resource (public member function) | |
| accesses the pointee if the resource handle is a pointer (public member function) | |
Non-member functions
creates a unique_resource, checking invalid value (function template) |
Deduction guides
Notes
Resource handle types satisfying NullablePointer can also be managed by std::unique_ptr. Unlike unique_ptr, unique_resource does not require NullablePointer.
Example
| This section is incomplete Reason: no example |
See also
| (C++11) |
smart pointer with unique object ownership semantics (class template) |