Clippy · Correctness

Float literal approximating a standard math constant

clippy::approx_constant

Use the matching constant from std::f64::consts (or f32) instead of a truncated literal.

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

Not a defect when

The literal is a value fixed by an external specification or test vector that merely resembles the constant, such as a 3.14 mandated by a file format or a reference output.

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

Set it once in rust-doctor.toml

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