Constant kvarn::prelude::utils::prelude::compact_str::core::f64::consts::FRAC_2_PI

pub const FRAC_2_PI: f64 = 0.636619772367581343075535053490057448f64; // 0.63661977236758138f64

Available on non-crate feature miri-test-libstd only.

2/π