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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 <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 pointer p is not the result of the allocate(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, and malloc_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 tbb::tbb_allocator as a type alias for which the non-member functions are reachable only via argument-dependent lookup.

template<typename T, typename U>
bool operator==(const tbb_allocator<T>&, const tbb_allocator<U>&) noexcept

Returns true.

template<typename T, typename U>
bool operator!=(const tbb_allocator<T>&, const tbb_allocator<U>&) noexcept

Returns false.

Memory Allocation scalable_allocator