Difference between revisions of "cpp/memory/construct at"
From cppreference.com
(simplify. use less standardese) |
(~) |
||
| Line 9: | Line 9: | ||
{{dcl end}} | {{dcl end}} | ||
| − | Creates a {{tt|T}} object initialized with arguments {{tt|args...}} at given address {{tt|p}}. {{cpp/enable_if|{{c|::new(std::declval<void*>()) T(std::declval<Args>()...)}} is well-formed in | + | Creates a {{tt|T}} object initialized with arguments {{tt|args...}} at given address {{tt|p}}. {{cpp/enable_if|{{c|::new(std::declval<void*>()) T(std::declval<Args>()...)}} is well-formed in unevaluated context}}. |
Equivalent to | Equivalent to | ||
Revision as of 23:31, 6 February 2020
| Defined in header <memory>
|
||
| template<class T, class... Args> constexpr T* construct_at( T* p, Args&&... args ); |
(since C++20) | |
Creates a T object initialized with arguments args... at given address p. This overload participates in overload resolution only if ::new(std::declval<void*>()) T(std::declval<Args>()...) is well-formed in unevaluated context.
Equivalent to
return ::new (const_cast<void*>(static_cast<const volatile void*>(p))) T(std::forward<Args>(args)...);
except that construct_at may be used in evaluation of constant expressions.
When construct_at is called in the evaluation of some constant expression e, the argument p must point to either storaged obtained by std::allocator<T>::allocate or an object whose lifetime began within the evaluation of e.
Contents |
Parameters
| p | - | pointer to the uninitialized storage on which a T object will be constructed
|
| args... | - | arguments used for initialization |
Return value
p
Example
| This section is incomplete Reason: no example |
See also
| [static] |
constructs an object in the allocated storage (function template) |
| (C++17) |
destroys an object at a given address (function template) |
