tbb_allocator¶
[memory_allocation.tbb_allocator]
A tbb_allocator
is a class template that models the allocator requirements from the [allocator.requirements] ISO C++ section.
The tbb_allocator
allocates and frees memory via the oneTBB malloc library if it is available,
otherwise, it reverts to using std::malloc
and std::free
.
// Defined in header <oneapi/tbb/tbb_allocator.h>
namespace oneapi {
namespace tbb {
template<typename T> class tbb_allocator {
public:
using value_type = T;
using size_type = std::size_t;
using propagate_on_container_move_assignment = std::true_type;
using is_always_equal = std::true_type;
enum malloc_type {
scalable,
standard
};
tbb_allocator() = default;
template<typename U>
tbb_allocator(const tbb_allocator<U>&) noexcept;
T* allocate(size_type);
void deallocate(T*, size_type);
static malloc_type allocator_type();
};
} // namespace tbb
} // namespace oneapi
Member Functions¶
-
void deallocate(T *p, size_type n)¶
Deallocates memory pointed to by
p
. The behavior is undefined if the pointerp
is not the result of theallocate(n)
method. The behavior is undefined if the memory has been already deallocated.
-
static malloc_type allocator_type()¶
Returns the enumeration type
malloc_type::scalable
if the oneTBB malloc library is available, andmalloc_type::standard
, otherwise.
Non-member Functions¶
These functions provide comparison operations between two tbb_allocator
instances.
template<typename T, typename U>
bool operator==(const tbb_allocator<T>&, const tbb_allocator<U>&) noexcept;
template<typename T, typename U>
bool operator!=(const tbb_allocator<T>&, const tbb_allocator<U>&) noexcept;
The namespace where these functions are defined is unspecified, as long as they may be used in respective binary operation expressions on tbb_allocator
objects.
For example, an implementation may define the classes and functions in the same unspecified internal namespace
and define oneapi::tbb::tbb_allocator
as a type alias for which the non-member functions are reachable only via argument-dependent lookup.