Difference between revisions of "cpp/experimental/observer ptr"
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{{dcl begin}} | {{dcl begin}} | ||
{{dcl header|experimental/memory}} | {{dcl header|experimental/memory}} | ||
| − | {{dcl | since=libfund_ts_2 || 1= | + | {{dcl|since=libfund_ts_2||1= |
template< class W > | template< class W > | ||
class observer_ptr; | class observer_ptr; | ||
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{{dcl end}} | {{dcl end}} | ||
| − | {{tt|std::experimental::observer_ptr}} is a non-owning pointer, or ''observer''. The observer stores a pointer to a second object, known as the ''watched object''. | + | {{tt|std::experimental::observer_ptr}} is a non-owning pointer, or ''observer''. The observer stores a pointer to a second object, known as the ''watched object''. An {{tt|observer_ptr}} may also have no watched object. |
An observer is not responsible in any way for the watched object; there is no inherent relationship between an observer and the object it watches. | An observer is not responsible in any way for the watched object; there is no inherent relationship between an observer and the object it watches. | ||
| − | Specializations of {{tt|observer_ptr}} satisfy the requirements of {{ | + | It is intended as a near drop-in replacement for raw pointer types, with the advantage that, as a vocabulary type, it indicates its intended use without need for detailed analysis by code readers. |
| + | |||
| + | Specializations of {{tt|observer_ptr}} satisfy the requirements of {{named req|CopyConstructible}} and {{named req|CopyAssignable}}. | ||
{{par begin}} | {{par begin}} | ||
{{par hreq}} | {{par hreq}} | ||
| − | {{par req | {{tt|W}} shall not be a reference type, but may be an incomplete type. }} | + | {{par req|{{tt|W}} shall not be a reference type, but may be an incomplete type.}} |
{{par end}} | {{par end}} | ||
===Member types=== | ===Member types=== | ||
{{dsc begin}} | {{dsc begin}} | ||
| − | {{dsc hitem | Member type | Definition}} | + | {{dsc hitem|Member type|Definition}} |
| − | {{dsc | {{c|element_type}} | {{tt|W}}, the type of the object watched by this {{tt|observer_ptr}} | + | {{dsc|{{c|element_type}}|{{tt|W}}, the type of the object watched by this {{tt|observer_ptr}}}} |
| − | + | ||
| − | + | ||
{{dsc end}} | {{dsc end}} | ||
===Member functions=== | ===Member functions=== | ||
{{dsc begin}} | {{dsc begin}} | ||
| − | {{dsc inc | cpp/experimental/observer_ptr/dsc constructor}} | + | {{dsc inc|cpp/experimental/observer_ptr/dsc constructor}} |
| − | {{dsc inc | cpp/experimental/observer_ptr/dsc destructor}} | + | {{dsc inc|cpp/experimental/observer_ptr/dsc destructor}} |
| − | {{dsc inc | cpp/experimental/observer_ptr/dsc operator{{=}}}} | + | {{dsc inc|cpp/experimental/observer_ptr/dsc operator{{=}}}} |
| − | {{dsc h2 | Modifiers}} | + | {{dsc h2|Modifiers}} |
| − | {{dsc inc | cpp/experimental/observer_ptr/dsc release}} | + | {{dsc inc|cpp/experimental/observer_ptr/dsc release}} |
| − | {{dsc inc | cpp/experimental/observer_ptr/dsc reset}} | + | {{dsc inc|cpp/experimental/observer_ptr/dsc reset}} |
| − | {{dsc inc | cpp/experimental/observer_ptr/dsc swap}} | + | {{dsc inc|cpp/experimental/observer_ptr/dsc swap}} |
| − | {{dsc h2 | Observers}} | + | {{dsc h2|Observers}} |
| − | {{dsc inc | cpp/experimental/observer_ptr/dsc get}} | + | {{dsc inc|cpp/experimental/observer_ptr/dsc get}} |
| − | {{dsc inc | cpp/experimental/observer_ptr/dsc operator bool}} | + | {{dsc inc|cpp/experimental/observer_ptr/dsc operator bool}} |
| − | {{dsc inc | cpp/experimental/observer_ptr/dsc operator* | + | {{dsc inc|cpp/experimental/observer_ptr/dsc operator*}} |
| − | + | ||
| − | + | ||
| − | + | ||
| + | {{dsc h2|Conversions}} | ||
| + | {{dsc inc|cpp/experimental/observer_ptr/dsc operator pointer}} | ||
{{dsc end}} | {{dsc end}} | ||
===Non-member functions=== | ===Non-member functions=== | ||
{{dsc begin}} | {{dsc begin}} | ||
| − | {{dsc inc | cpp/experimental/observer_ptr/dsc make_observer}} | + | {{dsc inc|cpp/experimental/observer_ptr/dsc make_observer}} |
| − | {{dsc inc | cpp/experimental/observer_ptr/dsc operator_cmp}} | + | {{dsc inc|cpp/experimental/observer_ptr/dsc operator_cmp}} |
| − | {{dsc inc | cpp/experimental/observer_ptr/dsc swap2}} | + | {{dsc inc|cpp/experimental/observer_ptr/dsc swap2}} |
{{dsc end}} | {{dsc end}} | ||
===Helper classes=== | ===Helper classes=== | ||
{{dsc begin}} | {{dsc begin}} | ||
| − | {{dsc inc | cpp/experimental/observer_ptr/dsc hash}} | + | {{dsc inc|cpp/experimental/observer_ptr/dsc hash}} |
{{dsc end}} | {{dsc end}} | ||
===Example=== | ===Example=== | ||
| − | {{example | + | {{example}} |
| − | + | ||
| − | + | {{langlinks|ru|zh}} | |
| − | }} | + | |
Latest revision as of 01:11, 28 November 2023
| Defined in header <experimental/memory>
|
||
| template< class W > class observer_ptr; |
(library fundamentals TS v2) | |
std::experimental::observer_ptr is a non-owning pointer, or observer. The observer stores a pointer to a second object, known as the watched object. An observer_ptr may also have no watched object.
An observer is not responsible in any way for the watched object; there is no inherent relationship between an observer and the object it watches.
It is intended as a near drop-in replacement for raw pointer types, with the advantage that, as a vocabulary type, it indicates its intended use without need for detailed analysis by code readers.
Specializations of observer_ptr satisfy the requirements of CopyConstructible and CopyAssignable.
| Type requirements | ||
-W shall not be a reference type, but may be an incomplete type.
|
Contents |
[edit] Member types
| Member type | Definition |
| element_type | W, the type of the object watched by this observer_ptr
|
[edit] Member functions
constructs a new observer_ptr (public member function) | |
| (destructor) (implicitly declared) |
destructs an observer_ptr (public member function) |
| operator= (implicitly declared) |
implicitly declared copy and move assignment operators that assign the stored pointer (public member function) |
Modifiers | |
| returns a pointer to the watched object and stops watching the object (public member function) | |
| replaces the watched object (public member function) | |
| swaps the watched objects (public member function) | |
Observers | |
| returns a pointer to the watched object (public member function) | |
| checks if there is an associated watched object (public member function) | |
| dereferences pointer to the watched object (public member function) | |
Conversions | |
| explicit conversion function to the stored pointer (public member function) | |
[edit] Non-member functions
creates an observer_ptr that watches an object (function template) | |
compares to another observer_ptr or with nullptr (function template) | |
specializes the swap algorithm (function template) |
[edit] Helper classes
hash support for observer_ptr (class template specialization) |
[edit] Example
| This section is incomplete Reason: no example |
