#neural #network #artificial #intelligence #ai

macro no-std mushin_derive

Compile-time creation of neural networks

2 releases

0.1.1 Apr 8, 2021
0.1.0 Apr 8, 2021

#1459 in Algorithms


61 lines

Mushin: Compile-time creation of neural networks

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Mushin is a Japanese term used in martial arts that refers to the state of mind obtained by practice. At this point, a person relies not on what they think should be the next move, but what is their trained natural reaction (or instinct).


Mushin allows the developer to build neural networks at compile-time, with preallocated arrays with well defined sizes. This has mainly three very important benefits:

  1. Compile-time network consistency check: Any defect in your neural network (i.e. mismatching layers inputs/outputs) will be raised at compile-time. You can enjoy your coffee while your network inference or training process never fails!
  2. Awesome Rust compiler optimizations: Because the neural network is completely defined at compile-time, the compiler is able to perform smart optimizations, like unrolling loops or injecting SIMD instructions.
  3. Support for embedded: The std library is not required to build neural networks so it can run on any target that Rust supports.


Add this to your Cargo.toml:

mushin = "0.1"
mushin_derive = "0.1"

And this is a very simple example to get you started:

use rand::distributions::Uniform;

use mushin::{activations::ReLu, layers::Dense, NeuralNetwork};
use mushin_derive::NeuralNetwork;

// Builds a neural network with 2 inputs and 1 output
// Made of 3 feed forward layers, you can have as many as you want and with any name
#[derive(NeuralNetwork, Debug)]
struct MyNetwork {
    // LayerType<ActivationType, # inputs, # outputs>
    input: Dense<ReLu, 2, 4>,
    hidden: Dense<ReLu, 4, 2>,
    output: Dense<ReLu, 2, 1>,

impl MyNetwork {
    // Initialize layer weights with a uniform distribution and set ReLU as activation function
    fn new() -> Self {
        let mut rng = rand::thread_rng();
        let dist = Uniform::from(-1.0..=1.0);

        MyNetwork {
            input: Dense::random(&mut rng, &dist),
            hidden: Dense::random(&mut rng, &dist),
            output: Dense::random(&mut rng, &dist),

fn main() {
    // Init the weights and perform a forward pass
    let nn = MyNetwork::new();
    println!("{:#?}", nn);

    let input = [0.0, 1.0];
    println!("Input: {:#?}", input);
    let output = nn.forward(input);
    println!("Output: {:#?}", output);

You may wonder how the forward method works. The NeuralNetwork derive macro defines it for you, and it looks like this for this particular example:

fn forward(&self, input: [f32; 2]) -> [f32; 1] {

Note how the forward method expects two input values because that's what the first (input) layer expects, and returns one single value because that's what the last layer (output) returns.


  • Compile-time neural network consistency check
  • Docs, CI/CD & Benchmarks
  • Backward pass
  • More layer types (convolution, dropout, lstm...)
  • More activation functions (sigmoid, softmax...)
  • Maaaybeee, CPU and/or GPU concurrency


If you find a vulnerability, bug or would like a new feature, open a new issue.

To introduce your changes into the codebase, submit a Pull Request.

Many thanks!


Mushin is distributed under the terms of both the MIT license and the Apache License (Version 2.0).



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