note: external requirements --> $DIR/propagate-approximated-val.rs:36:45 | LL | establish_relationships(cell_a, cell_b, |outlives1, outlives2, x, y| { | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: defining type: test::{closure#0} with closure args [ i16, for extern "rust-call" fn((std::cell::Cell<&'?1 &ReBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon }) u32>, std::cell::Cell<&ReBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon }) &'?2 u32>, std::cell::Cell<&ReBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon }) u32>, std::cell::Cell<&ReBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon }) u32>)), (), ] = note: late-bound region is '?3 = note: late-bound region is '?4 = note: number of external vids: 5 = note: where '?1: '?2 note: no external requirements --> $DIR/propagate-approximated-val.rs:35:1 | LL | fn test<'a, 'b>(cell_a: Cell<&'a u32>, cell_b: Cell<&'b u32>) { | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: defining type: test error: lifetime may not live long enough --> $DIR/propagate-approximated-val.rs:38:9 | LL | fn test<'a, 'b>(cell_a: Cell<&'a u32>, cell_b: Cell<&'b u32>) { | -- -- lifetime `'b` defined here | | | lifetime `'a` defined here ... LL | demand_y(outlives1, outlives2, x.get()) | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ argument requires that `'a` must outlive `'b` | = help: consider adding the following bound: `'a: 'b` error: aborting due to 1 previous error