rust - How to pass a member function of a struct to another struct as callback -

i want pass member function of struct struct.

sorry, poor english, can't more details.

use std::thread;  struct struct1 {}  impl struct1 {     pub fn do_some(&mut self, s: &str) {         // use s modify self     } }  struct struct2 {     cb1: box<fn(&mut struct1, &str)>, }  fn main() {     let s1 = struct1 {};      let s2 = struct2 {         cb1: box::new(s1.do_some),  // how store do_some function in cb1 ?     }; } 

you close! refer method or other symbol use :: separator , specify path said symbol. methods or associated functions live in namespace of type, therefore path of method struct1::do_some. in java use . operator access those, in rust . operator used on existing objects, not on type names.

the solution is:

let s2 = struct2 {     cb1: box::new(struct1::do_some), }; 

however, possibly improve type of function bit. box<fn(...)> boxed trait object, don't need if don't want work closures. if want refer "normal functions" (those don't have environment), can use function pointer instead:

struct struct2 {     cb1: fn(&mut struct1, &str), } 

note lowercase fn , don't need box.