Thrust

std::random (v0.2.2)

Random numbers and buffer filling.

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Overview

std::random produces pseudo-random unsigned integers and fills buffers with random bytes.

randomU64 and randomUsize return a random value, fillRandomBytes fills a buffer, and seedRandom seeds the generator.

Source: thrustc/std/v0.2.2/random.thrust

Public Signatures

Exported declarations for this module snapshot.

fn randomU64() u64 @public;
fn randomUsize() usize @public;
fn fillRandomBytes(buffer: ptr, length: usize) void @public;
fn seedRandom(seed: u64) void @public;

Behavior and Use

randomU64 and randomUsize return unsigned pseudo-random values; fillRandomBytes fills a buffer in place.

Call seedRandom before generating values if reproducible output is required.

Examples

import std::random;
import std::io;

// Roll a six-sided die using the low bits of a random number.
fn main() s32 @public {
    var roll: u64 = random::randomU64();

    io::print("die face: %d\n", ((roll % 6) as s32) + 1);

    return 0;
}
import std::random;
import std::io;

// Fill a buffer with random bytes, for example to build a token.
fn main() s32 @public {
    var token: array[u8; 4];

    random::seedRandom(123456);
    random::fillRandomBytes((ref token) as ptr, 4);

    io::print("token ready\n");

    return 0;
}
import std::random;
import std::io;

// Reuse a seed to reproduce the same random sequence.
fn main() s32 @public {
    random::seedRandom(999);
    var first: u64 = random::randomU64();

    random::seedRandom(999);
    var second: u64 = random::randomU64();

    if first == second {
        io::print("sequence reproduced\n");
    }

    return 0;
}

Notes

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