src/test/ui/lifetimes/bare-trait-object.rs

   1 // Verify that lifetime resolution correctly accounts for `Fn` bare trait objects.
   2 // check-pass
   3 #![allow(bare_trait_objects)]
   4
   5 // This should work as: fn next_u32(fill_buf: &mut dyn FnMut(&mut [u8]))
   6 fn next_u32(fill_buf: &mut FnMut(&mut [u8])) {
   7     let mut buf: [u8; 4] = [0; 4];
   8     fill_buf(&mut buf);
   9 }
  10
  11 fn explicit(fill_buf: &mut dyn FnMut(&mut [u8])) {
  12     let mut buf: [u8; 4] = [0; 4];
  13     fill_buf(&mut buf);
  14 }
  15
  16 fn main() {
  17     let _: fn(&mut FnMut(&mut [u8])) = next_u32;
  18     let _: &dyn Fn(&mut FnMut(&mut [u8])) = &next_u32;
  19     let _: fn(&mut FnMut(&mut [u8])) = explicit;
  20     let _: &dyn Fn(&mut FnMut(&mut [u8])) = &explicit;
  21     let _: fn(&mut dyn FnMut(&mut [u8])) = next_u32;
  22     let _: &dyn Fn(&mut dyn FnMut(&mut [u8])) = &next_u32;
  23     let _: fn(&mut dyn FnMut(&mut [u8])) = explicit;
  24     let _: &dyn Fn(&mut dyn FnMut(&mut [u8])) = &explicit;
  25 }