note: External requirements --> $DIR/ty-param-closure-approximate-lower-bound.rs:34:24 | LL | twice(cell, value, |a, b| invoke(a, b)); | ^^^^^^^^^^^^^^^^^^^ | = note: defining type: DefId(0/1:14 ~ ty_param_closure_approximate_lower_bound[317d]::generic[0]::{{closure}}[0]) with closure substs [ T, i16, for<'r, 's> extern "rust-call" fn((std::option::Option>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) T)) ] = note: number of external vids: 3 = note: where T: '_#1r note: No external requirements --> $DIR/ty-param-closure-approximate-lower-bound.rs:32:1 | LL | / fn generic(value: T) { LL | | let cell = Cell::new(&()); LL | | twice(cell, value, |a, b| invoke(a, b)); LL | | } | |_^ | = note: defining type: DefId(0/0:5 ~ ty_param_closure_approximate_lower_bound[317d]::generic[0]) with substs [ T ] note: External requirements --> $DIR/ty-param-closure-approximate-lower-bound.rs:39:24 | LL | twice(cell, value, |a, b| invoke(a, b)); | ^^^^^^^^^^^^^^^^^^^ | = note: defining type: DefId(0/1:17 ~ ty_param_closure_approximate_lower_bound[317d]::generic_fail[0]::{{closure}}[0]) with closure substs [ T, i16, for<'r, 's> extern "rust-call" fn((std::option::Option>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) T)) ] = note: number of external vids: 4 = note: where T: '_#1r note: No external requirements --> $DIR/ty-param-closure-approximate-lower-bound.rs:38:1 | LL | / fn generic_fail<'a, T>(cell: Cell<&'a ()>, value: T) { LL | | twice(cell, value, |a, b| invoke(a, b)); LL | | //~^ ERROR the parameter type `T` may not live long enough LL | | } | |_^ | = note: defining type: DefId(0/0:6 ~ ty_param_closure_approximate_lower_bound[317d]::generic_fail[0]) with substs [ T ] error[E0309]: the parameter type `T` may not live long enough --> $DIR/ty-param-closure-approximate-lower-bound.rs:39:24 | LL | twice(cell, value, |a, b| invoke(a, b)); | ^^^^^^^^^^^^^^^^^^^ | = help: consider adding an explicit lifetime bound `T: ReFree(DefId(0/0:6 ~ ty_param_closure_approximate_lower_bound[317d]::generic_fail[0]), BrNamed(crate0:DefIndex(1:15), 'a))`... error: aborting due to previous error For more information about this error, try `rustc --explain E0309`.