error: expected one of `,`, `:`, or `>`, found `=` --> $DIR/issue-34334.rs:2:29 | LL | let sr: Vec<(u32, _, _) = vec![]; | -- ^ expected one of `,`, `:`, or `>` | | | while parsing the type for `sr` | help: you might have meant to end the type parameters here | LL | let sr: Vec<(u32, _, _)> = vec![]; | + error[E0277]: a value of type `Vec<(u32, _, _)>` cannot be built from an iterator over elements of type `()` --> $DIR/issue-34334.rs:5:87 | LL | let sr2: Vec<(u32, _, _)> = sr.iter().map(|(faction, th_sender, th_receiver)| {}).collect(); | ^^^^^^^ value of type `Vec<(u32, _, _)>` cannot be built from `std::iter::Iterator` | = help: the trait `FromIterator<()>` is not implemented for `Vec<(u32, _, _)>` = help: the trait `FromIterator<(u32, _, _)>` is implemented for `Vec<(u32, _, _)>` = help: for that trait implementation, expected `(u32, _, _)`, found `()` note: the method call chain might not have had the expected associated types --> $DIR/issue-34334.rs:5:43 | LL | let sr: Vec<(u32, _, _) = vec![]; | ------ this expression has type `Vec<(_, _, _)>` ... LL | let sr2: Vec<(u32, _, _)> = sr.iter().map(|(faction, th_sender, th_receiver)| {}).collect(); | ------ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `Iterator::Item` changed to `()` here | | | `Iterator::Item` is `&(_, _, _)` here note: required by a bound in `collect` --> $SRC_DIR/core/src/iter/traits/iterator.rs:LL:COL error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0277`.