Macro try_with_rational_matrix 

macro_rules! try_with_rational_matrix {
    ($dim:expr, |$matrix:ident| -> $ret:ty $body:block $(,)?) => { ... };
    ($dim:expr, |mut $matrix:ident| -> $ret:ty $body:block $(,)?) => { ... };
    (@arm $d:literal, $matrix:ident, $ret:ty, $body:block) => { ... };
    (@arm_mut $d:literal, $matrix:ident, $ret:ty, $body:block) => { ... };
}

Available on crate feature exact only.

Fallibly dispatch a runtime dimension to a concrete exact rational matrix.

The macro creates a zero RationalMatrix with the selected const-generic dimension, then evaluates the supplied closure body. Dimensions 0..=8 are supported on stable Rust. The closure may fill the matrix through RationalMatrix::set or replace it with a value built by RationalMatrix::try_from_fn. The body may mutate or consume captured values. It is not evaluated for unsupported dimensions.

Errors

Returns LaError::UnsupportedDimension (converted through From<LaError>) when the requested dimension is greater than MAX_RATIONAL_MATRIX_DISPATCH_DIM. The closure body may return any other error representable by its declared Result type.

Examples

use la_stack::prelude::*;

let requested = 3usize;
let sign = try_with_rational_matrix!(requested, |mut matrix| -> Result<
    DeterminantSign,
    LaError,
> {
    for index in 0..requested {
        matrix.set(index, index, BigRational::from_integer(1.into()))?;
    }
    Ok(matrix.det_sign())
})?;
assert_eq!(sign, DeterminantSign::Positive);