std::math::rand ​

Type Aliases ​

type Seed: u64

Integer type of random seeds.

Structures ​

struct Rand

This structure implements a type of pseudo random number generator (PRNG). The seed must be given manually for each instance.

Seeds:

Seed is a number of seeds used to simulate randomness. The order and numbers produced vary depending on the seed. Since PRNGs are inherently deterministic, using a fixed seed means your program will generate the same numbers every time.

If you want to achieve randomness somehow, use a variable seed. A simple solution for seeds that will create the illusion of randomness is to use time. Unix-time seconds could be a simple seed solution.

Ranges:

This structure by default provides a function to simulate randomness between two numbers. But a way to do this can be suggested.

Here is basic range formula:
  ƒ(x) -> rand.Nextn(max - min) + min

With this formula, randomness can be made in the [min, max) range.

Methods:

static fn New(seed: Seed): &Rand
Returns new PRNG for seed.

fn Next63(self): i64
Returns a non-genative pseudo-random 63-bit signed integer as an 64-bit signed integer.

fn Next31(self): i32
Returns a non-genative pseudo-random 31-bit signed integer as an 31-bit signed integer.

fn Next(self): int
Returns a non-genative pseudo-random int.

fn Nextn63(self, n: i64): i64
Returns a non-genative pseudo-random in [0, n) range 63-bit signed integer as an 64-bit signed integer. If n <= 0, it panics.

fn Nextn31(self, n: i32): i32
Returns a non-genative pseudo-random in [0, n) range 31-bit signed integer as an 31-bit signed integer. If n <= 0, it panics.

fn Nextn(self, n: int): int
Returns a non-genative pseudo-random in [0, n) range as int. If n <= 0, it panics.

fn Fnext64(self): f64
Returns a non-genative pseudo-random in [0.0, 1.0) range as f64 floating-point.

fn Fnext32(self): f32
Returns a non-genative pseudo-random in [0.0, 1.0) range as f32 floating-point.