What Spectre and Meltdown Mean for WebKit(webkit.org)

    if is_pointer(pt):
        // do pointer-based stuff
    else:
        raise error

    struct __internal_variable {
        uint64_t type;
        void *data;
    }
    
    uint64_t __last_type = [number of builtin types];
    
    whenever you create a new type: increment __last_type and associate that type with the number;

    uint64_t typeof(__internal_variable var) {
        return var.type;
    }
    
    function[__last_type] typechecks;
    functions[] = void function(uint64_t type) { failure; }
    functions[int] = void function(uint64_t type) { success; }

    functions[typeof(myvar)]()