← Rule catalog

Clippy · Correctness

Ignored byte count from read or write

clippy::unused_io_amount

Use write_all or read_exact, or handle the byte count write and read return.

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

Not a defect when

The reader or writer is documented to always process the whole buffer, such as a Vec<u8> or a Cursor over a Vec, so a partial transfer cannot happen.

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

Set it once in rust-doctor.toml

Upstream

Clippy's own documentation for this lint

Other Correctness rules