Clippy · Correctness

Char position from enumerate used as byte index

clippy::char_indices_as_byte_indices

Iterate with char_indices(), which yields byte offsets, before using the index to slice or index the string.

Category: Correctness
Default level: warn
Tier: P1
Producer: Clippy
Diff scope: line

Not a defect when

The string is guaranteed ASCII-only (checked with is_ascii or produced from a fixed ASCII alphabet), so character positions and byte offsets coincide.

What it reads

Clippy, with the compiler behind it. The only pass that compiles.

Tier

Serious: worth interrupting other work for.

The tier bounds how severe a rule may be; its category bounds the tier.

Diff scope

The changed line itself.

What --scope contextual looks at to decide whether a change caused the finding.

Change it

Turn it off, or make it blocking, without touching the code it flags:

rust-doctor --rule clippy::char_indices_as_byte_indices=off .
rust-doctor --rule clippy::char_indices_as_byte_indices=error .

Set it once in rust-doctor.toml

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