this is my code.

lib.hpp

class MainMenuDriver {
public:
    static LiquidCrystal lcd;
    static std::vector<std::string> menu_items;
    static std::stack<std::string>  menu_stack;
    static std::stack<std::string>  temp_stack;
    // ...

main.cpp

#include "lib.hpp"

MainMenuDriver::lcd = LiquidCrystal(8, 9, 4, 5, 6, 7); // Error
// ...

Assume LiquidCrystal actually exists, as you can see here, I want to seperate the Blueprint and Operation into two different parts. I already know you can initialize lcd in MainMenuDriver's constructor but I want to call this constructor in a static way, meaning i do not want to create an instance of MainMenuDriver.

Thank you all in advance and have a nice day!

CodePudding user response：

You have to also specify the type when initializing the static data member lcd as shown below. Use

LiquidCrystal MainMenuDriver::lcd = LiquidCrystal(8, 9, 4, 5, 6, 7);