Always require Drop for generators.
This commit is contained in:
parent
9259da51ed
commit
03618d6afd
@ -109,6 +109,13 @@ fn next(&mut self) -> Option<NeedsDropResult<Ty<'tcx>>> {
|
||||
|
||||
for component in components {
|
||||
match *component.kind() {
|
||||
// The information required to determine whether a generator has drop is
|
||||
// computed on MIR, while this very method is used to build MIR. To avoid
|
||||
// cycles, we consider that generators always require drop.
|
||||
ty::Generator(..) if tcx.sess.opts.unstable_opts.drop_tracking_mir => {
|
||||
return Some(Err(AlwaysRequiresDrop));
|
||||
}
|
||||
|
||||
_ if component.is_copy_modulo_regions(tcx, self.param_env) => (),
|
||||
|
||||
ty::Closure(_, substs) => {
|
||||
|
@ -1,16 +1,24 @@
|
||||
error[E0597]: `a` does not live long enough
|
||||
--> $DIR/borrowing.rs:13:33
|
||||
|
|
||||
LL | let _b = {
|
||||
| -- borrow later stored here
|
||||
LL | let a = 3;
|
||||
LL | Pin::new(&mut || yield &a).resume(())
|
||||
| -- ^ borrowed value does not live long enough
|
||||
| |
|
||||
| ----------^
|
||||
| | |
|
||||
| | borrowed value does not live long enough
|
||||
| value captured here by generator
|
||||
| a temporary with access to the borrow is created here ...
|
||||
LL |
|
||||
LL | };
|
||||
| - `a` dropped here while still borrowed
|
||||
| -- ... and the borrow might be used here, when that temporary is dropped and runs the destructor for generator
|
||||
| |
|
||||
| `a` dropped here while still borrowed
|
||||
|
|
||||
= note: the temporary is part of an expression at the end of a block;
|
||||
consider forcing this temporary to be dropped sooner, before the block's local variables are dropped
|
||||
help: for example, you could save the expression's value in a new local variable `x` and then make `x` be the expression at the end of the block
|
||||
|
|
||||
LL | let x = Pin::new(&mut || yield &a).resume(()); x
|
||||
| +++++++ +++
|
||||
|
||||
error[E0597]: `a` does not live long enough
|
||||
--> $DIR/borrowing.rs:20:20
|
||||
|
@ -4,9 +4,10 @@ error[E0499]: cannot borrow `thing` as mutable more than once at a time
|
||||
LL | gen.as_mut().resume(&mut thing);
|
||||
| ---------- first mutable borrow occurs here
|
||||
LL | gen.as_mut().resume(&mut thing);
|
||||
| ------ ^^^^^^^^^^ second mutable borrow occurs here
|
||||
| |
|
||||
| first borrow later used by call
|
||||
| ^^^^^^^^^^ second mutable borrow occurs here
|
||||
LL |
|
||||
LL | }
|
||||
| - first borrow might be used here, when `gen` is dropped and runs the destructor for generator
|
||||
|
||||
error: aborting due to previous error
|
||||
|
||||
|
Loading…
Reference in New Issue
Block a user