rust/tests/ui/indexing_slicing_index.rs
Peter Jaszkowiak 21eae8ceb6 fix indexing_slicing with const
- should not fire if indexing with a constant block
- should not fire if indexing within a constant context
(const statement or const block)
2022-03-25 23:05:38 -06:00

49 lines
1.6 KiB
Rust

#![feature(inline_const)]
#![warn(clippy::indexing_slicing)]
// We also check the out_of_bounds_indexing lint here, because it lints similar things and
// we want to avoid false positives.
#![warn(clippy::out_of_bounds_indexing)]
#![allow(const_err, clippy::no_effect, clippy::unnecessary_operation)]
const ARR: [i32; 2] = [1, 2];
const REF: &i32 = &ARR[idx()]; // Ok, should not produce stderr.
const REF_ERR: &i32 = &ARR[idx4()]; // Ok, let rustc handle const contexts.
const fn idx() -> usize {
1
}
const fn idx4() -> usize {
4
}
fn main() {
let x = [1, 2, 3, 4];
let index: usize = 1;
x[index];
x[4]; // Ok, let rustc's `unconditional_panic` lint handle `usize` indexing on arrays.
x[1 << 3]; // Ok, let rustc's `unconditional_panic` lint handle `usize` indexing on arrays.
x[0]; // Ok, should not produce stderr.
x[3]; // Ok, should not produce stderr.
x[const { idx() }]; // Ok, should not produce stderr.
x[const { idx4() }]; // Ok, let rustc's `unconditional_panic` lint handle `usize` indexing on arrays.
const { &ARR[idx()] }; // Ok, should not produce stderr.
const { &ARR[idx4()] }; // Ok, let rustc handle const contexts.
let y = &x;
y[0]; // Ok, referencing shouldn't affect this lint. See the issue 6021
y[4]; // Ok, rustc will handle references too.
let v = vec![0; 5];
v[0];
v[10];
v[1 << 3];
const N: usize = 15; // Out of bounds
const M: usize = 3; // In bounds
x[N]; // Ok, let rustc's `unconditional_panic` lint handle `usize` indexing on arrays.
x[M]; // Ok, should not produce stderr.
v[N];
v[M];
}