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std::pmr::polymorphic_allocator::allocate_object(3) | C++ Standard Libary | std::pmr::polymorphic_allocator::allocate_object(3) |
NAME¶
std::pmr::polymorphic_allocator::allocate_object - std::pmr::polymorphic_allocator::allocate_object
Synopsis¶
template< class U > (since C++20)
[[nodiscard]] U* allocate_object( std::size_t n = 1 );
Allocates storage for n objects of type U using the underlying memory
resource.
If std::numeric_limits<std::size_t>::max() / sizeof(U) < n, throws
std::bad_array_new_length, otherwise equivalent to return
static_cast<U*>(allocate_bytes(n * sizeof(U), alignof(U)) );
Parameters¶
n - the number of objects to allocate storage for
Return value¶
A pointer to the allocated storage.
Notes¶
This function was introduced for use with the fully-specialized
allocator
std::pmr::polymorphic_allocator<>, but it may be useful in any
specialization as a
shortcut to avoid having to rebind from
std::pmr::polymorphic_allocator<T> to
std::pmr::polymorphic_allocator<U>.
Since U is not deduced, it must be provided as a template argument when
calling this
function.
Exceptions¶
Throws std::bad_array_new_length if n >
std::numeric_limits<std::size_t>::max() /
sizeof(U); may also be any exceptions thrown by the call to
resource()->allocate.
See also¶
allocate_bytes Allocate raw aligned memory from the underlying
resource
(C++20) (public member function)
new_object Allocates and constructs an object
(C++20) (public member function)
allocate Allocate memory
(public member function)
allocate allocates uninitialized storage using the allocator
[static] (public static member function of
std::allocator_traits<Alloc>)
allocate allocates memory
(public member function of std::pmr::memory_resource)
2022.07.31 | http://cppreference.com |