//класс, выделяющий и управляющий памятью
class allocator {
public:
    using size_type = std::size_t;
    using difference_type = std::ptrdiff_t;
    using pointer = T*;
    using const_pointer = const T*;
    using reference = typename std::add_lvalue_reference<T>::type;
    using const_reference = typename std::add_lvalue_reference<const T>::type;
    using value_type = T;

    allocator() noexcept = default;

    allocator(const allocator&) noexcept = default;

    template <class U>
    allocator(const allocator<U>&) noexcept {};

    ~allocator() = default;

    pointer allocate(size_type size) {
        auto p = ::operator new(size * sizeof(value_type));
        return static_cast<pointer>(p);
    }

    void deallocate(pointer p, size_type n) noexcept {
        ::operator delete (p, n);
    }
};