Rust 1.46.0
04488afe3

Casting between types

There is a new edition of the book and this is an old link.

A type cast expression is denoted with the binary operator as. Executing an as expression casts the value on the left-hand side to the type on the right-hand side.

fn average(values: &[f64]) -> f64 {
    let sum: f64 = sum(values);
    let size: f64 = len(values) as f64;
    sum / size
}

Here are the relevant sections in the new and old books:

• in the current edition: Appendix A — Keywords
• In the Rust Reference: Type Cast Expressions
• In the Rust documentation: mem::transmute
• In the first edition: Ch 3.29 — Casting between types