numeric cast may lose information

Why this fires¶

A numeric as may narrow a range, change signedness, discard a fractional part, or round an integer that is too large for the destination float.

let byte = large as u8 // warning[TE837]

Fix it¶

Use as? when only an exact value is acceptable:

if let byte = large as? u8 {
    send(byte)
}

When loss is intentional, use cast with a named rounding/overflow policy.

See also¶

• TE836 — checked cast has no valid path.