W3cubDocs

/C++

std::allocator_traits<Alloc>::allocate

Defined in header <memory>
(1) 
static pointer allocate( Alloc& a, size_type n );
 (since C++11)
(until C++20) 
[[nodiscard]] static pointer allocate( Alloc& a, size_type n );
 (since C++20)
(2) 
static pointer allocate( Alloc& a, size_type n,
                         const_void_pointer hint );
 (since C++11)
(until C++20) 
[[nodiscard]] static pointer allocate( Alloc& a, size_type n,
                                       const_void_pointer hint );
 (since C++20)

Uses the allocator a to allocate n*sizeof(Alloc::value_type) bytes of uninitialized storage.

1) Calls a.allocate(n)
2) Additionally passes memory locality hint hint. Calls a.allocate(n, hint) if possible. If not possible (e.g. a has no two-argument member function allocate()), calls a.allocate(n)

Parameters

a - allocator to use
n - the number of objects to allocate storage for
hint - pointer to a nearby memory location

Return value

The pointer returned by the call to a.allocate(n).

See also

allocates uninitialized storage
(public member function of std::allocator<T>)

© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
http://en.cppreference.com/w/cpp/memory/allocator_traits/allocate