note: external requirements
  --> $DIR/ty-param-closure-approximate-lower-bound.rs:24:24
   |
LL |     twice(cell, value, |a, b| invoke(a, b));
   |                        ^^^^^^
   |
   = note: defining type: generic::<T>::{closure#0} with closure args [
               i16,
               for<Region(BrAnon), Region(BrAnon)> extern "rust-call" fn((std::option::Option<std::cell::Cell<&'?1 &ReBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon }) ()>>, &ReBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon }) T)),
               (),
           ]
   = note: number of external vids: 2
   = note: where T: '?1

note: no external requirements
  --> $DIR/ty-param-closure-approximate-lower-bound.rs:22:1
   |
LL | fn generic<T>(value: T) {
   | ^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: defining type: generic::<T>

note: external requirements
  --> $DIR/ty-param-closure-approximate-lower-bound.rs:29:24
   |
LL |     twice(cell, value, |a, b| invoke(a, b));
   |                        ^^^^^^
   |
   = note: defining type: generic_fail::<T>::{closure#0} with closure args [
               i16,
               for<Region(BrAnon), Region(BrAnon)> extern "rust-call" fn((std::option::Option<std::cell::Cell<&'?1 &ReBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon }) ()>>, &ReBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon }) T)),
               (),
           ]
   = note: late-bound region is '?2
   = note: number of external vids: 3
   = note: where T: '?1

note: no external requirements
  --> $DIR/ty-param-closure-approximate-lower-bound.rs:28:1
   |
LL | fn generic_fail<'a, T>(cell: Cell<&'a ()>, value: T) {
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: defining type: generic_fail::<T>

error[E0309]: the parameter type `T` may not live long enough
  --> $DIR/ty-param-closure-approximate-lower-bound.rs:29:31
   |
LL | fn generic_fail<'a, T>(cell: Cell<&'a ()>, value: T) {
   |                 -- the parameter type `T` must be valid for the lifetime `'a` as defined here...
LL |     twice(cell, value, |a, b| invoke(a, b));
   |                               ^^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds
   |
help: consider adding an explicit lifetime bound
   |
LL | fn generic_fail<'a, T: 'a>(cell: Cell<&'a ()>, value: T) {
   |                      ++++

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0309`.