// Issue 34101: Circa 2016-06-05, `fn inline` below issued an // erroneous warning from the elaborate_drops pass about moving out of // a field in `Foo`, which has a destructor (and thus cannot have // content moved out of it). The reason that the warning is erroneous // in this case is that we are doing a *replace*, not a move, of the // content in question, and it is okay to replace fields within `Foo`. // // Another more subtle problem was that the elaborate_drops was // creating a separate drop flag for that internally replaced content, // even though the compiler should enforce an invariant that any drop // flag for such subcontent of `Foo` will always have the same value // as the drop flag for `Foo` itself. // compile-pass struct Foo(String); impl Drop for Foo { fn drop(&mut self) {} } fn inline() { // (dummy variable so `f` gets assigned `var1` in MIR for both fn's) let _s = (); let mut f = Foo(String::from("foo")); f.0 = String::from("bar"); } fn outline() { let _s = String::from("foo"); let mut f = Foo(_s); f.0 = String::from("bar"); } fn main() { inline(); outline(); }