Pedantic suggestion of using an array type definition

What it does

Suggests to define a array type alias to simplify the code, making it more readable.

Lint Name

use_array_type_alias

Category

pedantic

Advantage

No response

Drawbacks

No response

Example

In this small program from the Benchmarks Game:
https://benchmarksgame-team.pages.debian.net/benchmarksgame/program/mandelbrot-rust-6.html

There are lines of code like:

fn clr_pixels_nle(v : &[f64x2;4], f: f64, pix8 : &mut u8){
...
fn calc_sum(r: &mut [f64x2;4], i : &mut[f64x2;4], sum : &mut[f64x2;4], init_r: &[f64x2;4], init_i : f64x2){
...
fn mand8(init_r: &[f64x2;4], init_i : f64x2) -> u8 {
...

I suggest to add a lint in clippy::pedantic that suggests to define something like:

type Array1 = [f64x2; 4];

And then use that type in the above code, like:

fn clr_pixels_nle(v: &Array1, f: f64, pix8: &mut u8) {
...
fn calc_sum(r: &mut Array1, i: &mut Array1, sum: &mut Array1, init_r: &Array1, init_i: f64x2) {
...
fn mand8(init_r: &Array1, init_i: f64x2) -> u8 {
...

Defining type aliases to simplify array arguments in Rust code is quite under-used.

Start with the proposed clippy::pedantic lint named use_array_type_alias and review the Rust examples in the issue, especially the repeated [f64x2; 4] arguments. Define the applicability and expected diagnostic, then add the lint and tests showing when the array type alias suggestion is emitted.