Code compiles but Rust-analyzer makes error.

[RylanYancey]

rust-analyzer version: rust-analyzer version: 0.3.1131-standalone (897a7ec 2022-07-17)

rustc version: 1.62.1

relevant settings:
Bug appears on both Windows and WSL. On Windows 11 / Ubuntu 20.04

The code compiles and runs fine, no issues, but Rust-analyzer gives me an error when using DMatrix (typed as Matrix)'s associated functions.

Code example:

extern crate csv;
use csv::Reader;

use std::vec::Vec;
use std::fs;

extern crate nalgebra as na;
type Matrix = na::DMatrix<f32>

pub struct Dataset <const I: usize, const A: usize> {
    filename: String,
    dataset: Vec<Matrix>,
}

impl <const I: usize, const A: usize> Dataset <I, A> {

    pub fn new(name: &str) -> Self {
        Dataset { filename: name.to_string(), dataset: Vec::new() }
    }

    pub fn load_csv<F: Fn(&Vec<String>, &mut [[f32; I]; A])>(&mut self, conversion: F) {
        let contents = fs::read_to_string(
                "data/".to_string() + &self.filename + ".csv").unwrap();

        let mut reader = csv::ReaderBuilder::new()
            .delimiter(b',')
            .from_reader(contents.as_bytes());

        let mut output = [[0.0; I]; A];

        for result in reader.records() {

            let record = result.unwrap();
            let mut features: Vec<String> = Vec::new();

            for f in &record {
                features.push(f.to_string());
            }   

            (conversion)(&features, &mut output);

            let newmat = Matrix::from_fn(I - 1, A - 1, |i, j| { //<--- Error occurs here
                output[i][j]
            });

        }
    }
}

Error:

This code lines up with nalgebra's documentation, as found here: https://nalgebra.org/docs/user_guide/vectors_and_matrices#matrix-construction
Cargo.toml:

[package]
name = "canyon"
version = "0.1.0"
edition = "2021"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
nalgebra = "0.31.0"
csv = "1.1.6"

[lnicola]

CC #5441.

[RylanYancey]

CC #5441.

Interesting, looks like this issue has been persisting since 2019? Is there a known workaround?

It is kind of annoying to see the red

[lnicola]

You can add it to rust-analyzer.diagnostics.disabled.