rust-lang/rust-clippy
Ver no GitHubneedless_range_loop produces code with different behaviour
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#6.930 aberto em 18 de mar. de 2021
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Description
needless_range_loop suggests changing:
pub fn foo_a(out: &mut Vec<usize>, inx: &[usize], base: usize) {
for i in 1 .. base {
out[i] = *inx.get(i).unwrap_or(&0);
}
}
to
pub fn foo_b(out: &mut Vec<usize>, inx: &[usize], base: usize) {
for (i, item) in out.iter_mut().enumerate().take(base).skip(1) {
*item = *inx.get(i).unwrap_or(&0);
}
}
However, these are only equivalent is out has at least base elements. If not, then this changes behaviour (the first version panics with out of bounds, the second silently truncates the loop).
See this example at https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=6f00aec168a98758df574f0734a2233e (edit: this link was previously broken, thanks)
(I noticed this will discussing needless_range_loop in #6075 )