Code Example Template
let is_active: bool = true;
let is_greater: bool = 10 > 5;

Deep-Dive System Documentation

Booleans in Rust

The bool type represents logical boolean values in Rust and has two possible values: true and false. Booleans are exactly one byte in size and are highly integrated with Rust's strict compile-time type-safety rules—they do not implicitly convert to integers like in C/C++.

let is_active: bool = true;
if is_active {
    println!("System active.");
}

Useful Methods

.then<T, F>(f: F) -> Option<T> where F: FnOnce() -> T

Returns Some(f()) if the bool is true, and None otherwise. Use this to conditionally execute lazy initialization.

let debug_enabled = true;
let log_buffer = debug_enabled.then(|| vec![0u8; 1024]);
assert_eq!(log_buffer.is_some(), true);

.then_some<T>(t: T) -> Option<T>

Returns Some(t) if the bool is true, and None otherwise. Note that the argument t is evaluated eagerly.

let has_permission = false;
let access_token = has_permission.then_some("SECRET_TOKEN");
assert_eq!(access_token, None);

Quick Reference Guide

let t: bool = true;
let f: bool = false;