For example i want to make class_1 that have std::vector<float> and std::vector <class_2> and class_2 will have std::vector<float>. So i want to sum each float from class_1 to every float from class_2. I coming to the point , that it is hard to me create array from that values, that i can easily input to OpenCL kernel, and i want to use directly host memory from kernel. Thought that CL_USE_HOST_PTR will help but i dont know how to use. Didnot found any example, tried to change from CL_MEM_READ_ONLY to CL_USE_HOST_PTR and ofc = mistake. So how to use this CL_USE_HOST_PTR correctly?

The pointer you pass needs to point to the actual data, not a container. So pass the address of the first element (e.g., something like &myContainer[0]).

So i do. But anyway error with argument.