"cannot borrow data in a & reference as mutable" error

[DevinR528]

How can I use mutable lazy_static?

Thanks for your hint, I found the following code in Stackoverflow. #[macro_use] extern crate lazy_static; use std::sync::Mutex; lazy_static! { static ref ARRAY: Mutex<Vec<u8>> = Mutex::new(vec![]); } fn do_a_call() { ARRAY.lock().unwrap().push(1); } fn main() { do_a_call(); do_a_call(); do_a_call(); println!("called {}", ARRAY.lock().unwrap().len()); } Thank you!