#![warn(clippy::needless_range_loop, clippy::manual_memcpy)] const LOOP_OFFSET: usize = 5000; pub fn manual_copy(src: &[i32], dst: &mut [i32], dst2: &mut [i32]) { // plain manual memcpy for i in 0..src.len() { dst[i] = src[i]; } // dst offset memcpy for i in 0..src.len() { dst[i + 10] = src[i]; } // src offset memcpy for i in 0..src.len() { dst[i] = src[i + 10]; } // src offset memcpy for i in 11..src.len() { dst[i] = src[i - 10]; } // overwrite entire dst for i in 0..dst.len() { dst[i] = src[i]; } // manual copy with branch - can't easily convert to memcpy! for i in 0..src.len() { dst[i] = src[i]; if dst[i] > 5 { break; } } // multiple copies - suggest two memcpy statements for i in 10..256 { dst[i] = src[i - 5]; dst2[i + 500] = src[i] } // this is a reversal - the copy lint shouldn't be triggered for i in 10..LOOP_OFFSET { dst[i + LOOP_OFFSET] = src[LOOP_OFFSET - i]; } let some_var = 5; // Offset in variable for i in 10..LOOP_OFFSET { dst[i + LOOP_OFFSET] = src[i - some_var]; } // Non continuous copy - don't trigger lint for i in 0..10 { dst[i + i] = src[i]; } let src_vec = vec![1, 2, 3, 4, 5]; let mut dst_vec = vec![0, 0, 0, 0, 0]; // make sure vectors are supported for i in 0..src_vec.len() { dst_vec[i] = src_vec[i]; } // lint should not trigger when either // source or destination type is not // slice-like, like DummyStruct struct DummyStruct(i32); impl ::std::ops::Index for DummyStruct { type Output = i32; fn index(&self, _: usize) -> &i32 { &self.0 } } let src = DummyStruct(5); let mut dst_vec = vec![0; 10]; for i in 0..10 { dst_vec[i] = src[i]; } // Simplify suggestion (issue #3004) let src = [0, 1, 2, 3, 4]; let mut dst = [0, 0, 0, 0, 0, 0]; let from = 1; for i in from..from + src.len() { dst[i] = src[i - from]; } for i in from..from + 3 { dst[i] = src[i - from]; } // `RangeTo` `for` loop - don't trigger lint for i in 0.. { dst[i] = src[i]; } } #[warn(clippy::needless_range_loop, clippy::manual_memcpy)] pub fn manual_clone(src: &[String], dst: &mut [String]) { for i in 0..src.len() { dst[i] = src[i].clone(); } } fn main() {}