Dynamic memory management
Smart pointers
(until C++17)
Memory resources
Uninitialized storage
Uninitialized memory algorithms
Constrained uninitialized memory algorithms
Garbage collection support
C Library
Low level memory management
T* allocate( std::size_t n );
(since C++17)
(until C++20)
[[nodiscard]] T* allocate( std::size_t n );
(since C++20)

Allocates storage for n objects of type T using the underlying memory resource. Equivalent to return static_cast<T*>(resource()->allocate(n * sizeof(T), alignof(T)));.


[edit] Parameters

n - the number of objects to allocate storage for

[edit] Return value

A pointer to the allocated storage.

[edit] Exceptions

Throws std::bad_array_new_length if n > std::numeric_limits<std::size_t>::max() / sizeof(T); may also any exceptions thrown by the call to resource()->allocate.

[edit] 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 3038 C++17 allocate might allocate storage of wrong size throws length_error instead
LWG 3237 C++17 the exception thrown by allocate was inconsistent with std::allocator::allocate made consistent

[edit] See also

Allocate raw aligned memory from the underlying resource
(public member function) [edit]
Allocates raw memory suitable for an object or an array
(public member function) [edit]
Allocates and constructs an object
(public member function) [edit]
allocates uninitialized storage using the allocator
(public static member function of std::allocator_traits<Alloc>) [edit]
allocates memory
(public member function of std::pmr::memory_resource) [edit]