我目前正在学习多态分配器，我看了一些视频，并试图理解它。如果我有这样的代码：

class MyClass {
public:
    MyClass(int val = 0) : m_val(val) {
        std::cout << "MyClass constructed with value: " << val << std::endl;
    }
    ~MyClass() {
        std::cout << "MyClass destroyed with value: " << m_val << std::endl;
    }
private:
    int m_val;
};
int main() {
    char buffer[1024];
    std::size_t buffer_size = sizeof(buffer);
    // Use a monotonic buffer resource
    {
        std::pmr::monotonic_buffer_resource buffer_resource{buffer, buffer_size, std::pmr::null_memory_resource()};
        std::pmr::polymorphic_allocator<byte> allocator{ &buffer_resource };
        //std::pmr::polymorphic_allocator<MyClass> allocator{ &buffer_resource }; //still OK to use
        {
            std::pmr::vector<MyClass> vec(allocator);
            vec.reserve(256);
            for(int i = 0; i < 256; i++){
                vec.emplace_back(i);
            }
        }
    }
    return 0;
}

std::pmr::polymorphic_allocator<byte>和std::pmr::polymorphic_allocator<MyClass>有什么区别？为什么两者都能正常工作？