Using the Raspberry Pi Pico SDK, I see that the repeating_timer callback functions have option input for user data. However, the gpio_set_irq_callback function has no user data parameter.

Is there a way to access the member variables from gpio callback?

Should I go about implementing a user data parameter by changing my local sdk? How would I go about this?

void callback(uint gpio, uint32_t event_mask){
    if(gpio_get(pina)){
        //I want to call lcdmenu.up()
    }
    else{
        //lcdmenu.down()
    }
}


class lcdmenu
{
protected:
    command **items;
    int menutop = 0;
    int numitems;
    int menuselect = 0;   

public:
    lcdmenu(command **list, int length);
    void render();
    void down();
    void up();
    void enter();

};

lcdmenu::lcdmenu(command **list, int length)
{

    gpio_set_irq_enabled_with_callback(pinb, GPIO_IRQ_EDGE_FALL, true, &callback);
    numitems = length;
    items = list;
    render();
}