Show error in function if some other function has not run before it

November 26, 2021

I have two functions in C library that I am making.
One is a setup function, other is a function that does some operations. I want the second operations function to print an error if the setup function has not run before it.
What would be the best way to do this?

Here is what I have in my mind, but I am not sure if that is how it is done.

The setup function:

void setup_function()
{
    #ifndef FUNCTION_SETUP
    #define FUNCTION_SETUP
    a_init();
    b_init();
    c_init();
    #endif
}

And the operations function:

bool operations()
{
    #ifdef FUNCTION_SETUP
    try
    {
        /* My code */
        return true;
    }
    catch (...)
    {
        Serial.println("Error in operations");
        return false;
    }
    #elif Serial.println("Function not setup. Please use setup_function() in void setup()");
    #endif
}

>Solution :

#ifndef only checks whether this function was defined somewhere for the compiler and won’t affect runtime.

best way to do this is through use of a global variable that changes value once the setup function is executed. if you’re defining these functions in classes you could use static data member and setup function