vrd 0.0.10

A lightweight, no_std-friendly random number generator backed by Xoshiro256++ with optional Mersenne Twister support.
Documentation 
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// Copyright © 2023-2026 vrd. All rights reserved.
// SPDX-License-Identifier: Apache-2.0 OR MIT

//! Inspecting and customizing `MersenneTwisterConfig`.
//!
//! Run: `cargo run --example config`

#[path = "support.rs"]
mod support;

use vrd::{MersenneTwisterConfig, MersenneTwisterParams};

fn main() {
    support::header("vrd -- config");

    support::task_with_output(
        "Default config = canonical MT19937",
        || {
            let cfg = MersenneTwisterConfig::<624, 397>::default();
            vec![
                format!(
                    "matrix_a         = 0x{:08x}",
                    cfg.params.matrix_a
                ),
                format!(
                    "upper_mask       = 0x{:08x}",
                    cfg.params.upper_mask
                ),
                format!(
                    "lower_mask       = 0x{:08x}",
                    cfg.params.lower_mask
                ),
                format!(
                    "tempering_mask_b = 0x{:08x}",
                    cfg.params.tempering_mask_b
                ),
                format!(
                    "tempering_mask_c = 0x{:08x}",
                    cfg.params.tempering_mask_c
                ),
            ]
        },
    );

    support::task_with_output(
        "Validation rejects non-canonical params",
        || {
            let params = MersenneTwisterParams {
                matrix_a: 0x12345678, // highest bit not set -> reject
                ..MersenneTwisterParams::default()
            };
            let result =
                MersenneTwisterConfig::<624, 397>::validate(&params);
            vec![format!("validate(bad matrix_a) = {result:?}")]
        },
    );

    support::task_with_output(
        "Display impl summarises the params",
        || {
            let cfg = MersenneTwisterConfig::<624, 397>::default();
            vec![format!("{cfg}")]
        },
    );

    support::summary(3);
}