Function euler_gamma 

pub fn euler_gamma(precision: usize) -> DBig

Compute the Euler–Mascheroni constant γ ≈ 0.5772156649… to precision significant decimal digits (capped at 200).

Examples

let g = oxinum_float::special::euler_gamma(30);
assert!(g.to_string().starts_with("0.577215664901532860606512"));