// run-rustfix #![allow(dead_code)] /// Calls which should trigger the `UNNECESSARY_FOLD` lint fn unnecessary_fold() { // Can be replaced by .any let _ = (0..3).fold(false, |acc, x| acc || x > 2); // Can be replaced by .all let _ = (0..3).fold(true, |acc, x| acc && x > 2); // Can be replaced by .sum let _: i32 = (0..3).fold(0, |acc, x| acc + x); // Can be replaced by .product let _: i32 = (0..3).fold(1, |acc, x| acc * x); } /// Should trigger the `UNNECESSARY_FOLD` lint, with an error span including exactly `.fold(...)` fn unnecessary_fold_span_for_multi_element_chain() { let _: bool = (0..3).map(|x| 2 * x).fold(false, |acc, x| acc || x > 2); } /// Calls which should not trigger the `UNNECESSARY_FOLD` lint fn unnecessary_fold_should_ignore() { let _ = (0..3).fold(true, |acc, x| acc || x > 2); let _ = (0..3).fold(false, |acc, x| acc && x > 2); let _ = (0..3).fold(1, |acc, x| acc + x); let _ = (0..3).fold(0, |acc, x| acc * x); let _ = (0..3).fold(0, |acc, x| 1 + acc + x); // We only match against an accumulator on the left // hand side. We could lint for .sum and .product when // it's on the right, but don't for now (and this wouldn't // be valid if we extended the lint to cover arbitrary numeric // types). let _ = (0..3).fold(false, |acc, x| x > 2 || acc); let _ = (0..3).fold(true, |acc, x| x > 2 && acc); let _ = (0..3).fold(0, |acc, x| x + acc); let _ = (0..3).fold(1, |acc, x| x * acc); let _ = [(0..2), (0..3)].iter().fold(0, |a, b| a + b.len()); let _ = [(0..2), (0..3)].iter().fold(1, |a, b| a * b.len()); } fn main() {}