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 oneAPI Threading Building Blocks malloc library if it is available,
otherwise it reverts to using std::malloc and std::free.
// Defined in header <tbb/tbb_allocator.h>
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();
};
}
Member Functions¶
-
T *
allocate(size_type n) Allocates
n * sizeof(T)bytes. Returns a pointer to the allocated memory.
-
void
deallocate(T *p, size_type n) Deallocates memory pointed to by
p. The behavior is undefined if the pointerpis 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::scalableif the oneAPI TBB malloc library is available andmalloc_type::standardotherwise.
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 tbb::tbb_allocator as a type alias for which the non-member functions are reachable only via argument dependent lookup.