std::allocator<T>::construct

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< cpp‎ | memory‎ | allocator
Memory management library
(exposition only*)
Uninitialized memory algorithms
(C++17)
(C++17)
(C++17)
(C++20)
Constrained uninitialized
memory algorithms
(C++20)
C Library

Allocators
(C++11)
(C++11)
Memory resources
Garbage collection support
(C++11)(until C++23)
(C++11)(until C++23)
(C++11)(until C++23)
(C++11)(until C++23)
(C++11)(until C++23)
(C++11)(until C++23)
Uninitialized storage
(until C++20*)
(until C++20*)
(until C++20*)
Explicit lifetime management
std::allocator
Member functions
(until C++20)
(until C++20)
allocator::construct
(until C++20)
(until C++20)
Non-member functions
(until C++20)
Defined in header <memory>
void construct( pointer p, const_reference val );
(1) (until C++11)
template < class U, class... Args >
void construct( U* p, Args&&... args ) ;
(2) (since C++11)
(deprecated in C++17)
(removed in C++20)

Constructs an object of type T in allocated uninitialized storage pointed to by p, using global placement-new.

1) Calls :: new ( ( void * )p) T(val)
2) Calls :: new ( ( void * )p) U( std::forward <Args> (args)...)

Parameters

p - pointer to allocated uninitialized storage
val - the value to use as the copy constructor argument
args... - the constructor arguments to use

Return value

(none)

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR Applied to Behavior as published Correct behavior
LWG 402 C++98 if T::operator new exists, the program might be ill-formed uses global replacement-new instead

See also

[static]
constructs an object in the allocated storage
(function template)
(C++20)
creates an object at a given address
(function template)
allocation functions
(function)