#![allow(clippy::uninlined_format_args)] use std::iter::repeat; fn square_is_lower_64(x: &u32) -> bool { x * x < 64 } #[allow(clippy::maybe_infinite_iter)] #[deny(clippy::infinite_iter)] fn infinite_iters() { repeat(0_u8).collect::<Vec<_>>(); //~^ ERROR: infinite iteration detected // infinite iter (0..8_u32).take_while(square_is_lower_64).cycle().count(); //~^ ERROR: infinite iteration detected // infinite iter (0..8_u64).chain(0..).max(); //~^ ERROR: infinite iteration detected // infinite iter (0_usize..) .chain([0usize, 1, 2].iter().cloned()) .skip_while(|x| *x != 42) .min(); // infinite iter (0..8_u32) //~^ ERROR: infinite iteration detected .rev() .cycle() .map(|x| x + 1_u32) .for_each(|x| println!("{}", x)); // infinite iter (0..3_u32).flat_map(|x| x..).sum::<u32>(); // infinite iter (0_usize..).flat_map(|x| 0..x).product::<usize>(); //~^ ERROR: infinite iteration detected // infinite iter (0_u64..).filter(|x| x % 2 == 0).last(); //~^ ERROR: infinite iteration detected // not an infinite, because ranges are double-ended (0..42_u64).by_ref().last(); // iterator is not exhausted (0..).next(); } #[deny(clippy::maybe_infinite_iter)] fn potential_infinite_iters() { // maybe infinite iter (0..).zip((0..).take_while(square_is_lower_64)).count(); //~^ ERROR: possible infinite iteration detected // maybe infinite iter repeat(42).take_while(|x| *x == 42).chain(0..42).max(); //~^ ERROR: possible infinite iteration detected // maybe infinite iter (1..) //~^ ERROR: possible infinite iteration detected .scan(0, |state, x| { *state += x; Some(*state) }) .min(); // maybe infinite iter (0..).find(|x| *x == 24); //~^ ERROR: possible infinite iteration detected // maybe infinite iter (0..).position(|x| x == 24); //~^ ERROR: possible infinite iteration detected // maybe infinite iter (0..).any(|x| x == 24); //~^ ERROR: possible infinite iteration detected // maybe infinite iter (0..).all(|x| x == 24); //~^ ERROR: possible infinite iteration detected // not infinite (0..).zip(0..42).take_while(|&(x, _)| x != 42).count(); // iterator is not exhausted repeat(42).take_while(|x| *x == 42).next(); } fn main() { infinite_iters(); potential_infinite_iters(); } mod finite_collect { use std::collections::HashSet; struct C; impl FromIterator<i32> for C { fn from_iter<I: IntoIterator<Item = i32>>(iter: I) -> Self { C } } fn check_collect() { // Infinite iter let _: HashSet<i32> = (0..).collect(); //~^ ERROR: infinite iteration detected //~| NOTE: `#[deny(clippy::infinite_iter)]` on by default // Some data structures don't collect infinitely, such as `ArrayVec` let _: C = (0..).collect(); } }