error[E0277]: a value of type `Bar` cannot be built from an iterator over elements of type `_` --> $DIR/branches.rs:19:9 | LL | std::iter::empty().collect() | ^^^^^^^^^^^^^^^^^^ ------- required by a bound introduced by this call | | | value of type `Bar` cannot be built from `std::iter::Iterator` | = help: the trait `FromIterator<_>` is not implemented for `Bar` note: required by a bound in `collect` --> $SRC_DIR/core/src/iter/traits/iterator.rs:LL:COL | LL | fn collect>(self) -> B | ^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `collect` error: aborting due to previous error For more information about this error, try `rustc --explain E0277`.