Access a fast, pre-initialized generator

This is a handle to the local ThreadRng.

Example

// Using a local binding avoids an initialization-check on each usage:
let rng = rand::rng();

println!("True or false: {}", rng.random::<bool>());
println!("A simulated die roll: {}", rng.random_range::<u64>(1..=6));

Security

Refer to [ThreadRng#Security].