I'm writing a library in Rust that implements a certain struct and methods on it. I want, however, to expose to the consumer only the methods and leave the state variables hidden, with just a few exposed through getter functions. As an example of the sort of behavior I want, here's a C snippet:

//library.h
void init();
void do_stuff();
int get();

//library.c
typedef struct State {
    int a,b;
} State;

State G_STATE;

void init() {} //Initialize G_STATE
void do_stuff() {} //Logic with G_STATE
int get() { return G_STATE.a; } //Returns only part of G_STATE

//main.c
#include <stdio.h>
#include "library.h"
int main() {
    init();
    do_stuff();
    printf(get());
    return 0;
}

This is clearly very unsafe and all that, but it's enough to describe the behavior. Is there an idiomatic Rust way to get this style of API? A way that, perhaps also doesn't have the same shortcomings as the snippet above in terms of memory safety and undefined lifetimes of globals?