许杰友 Jieyou Xu (Joe) 61671a7e34 Rollup merge of #125253 - sunsided:feature/FRAC_1_SQRT_PI, r=Mark-Simulacrum ... Add `FRAC_1_SQRT_2PI` constant to f16/f32/f64/f128 This adds the `FRAC_1_SQRT_2PI` to the `f16`, `f32`, `f64` and `f128` as [`1/√(2π)`](https://www.wolframalpha.com/input?i=1%2Fsqrt%282*pi%29). The rationale is that while `FRAC_1_SQRT_PI` already exists, [Gaussian calculations](https://en.wikipedia.org/wiki/Gaussian_function) for random normal distributions require a `1/(σ√(2π))` term, which could then be directly expressed e.g. as `f32::FRAC_1_SQRT_2PI / sigma`. The actual value is approximately `1/√(2π) = 0.3989422804014326779399460599343818684758586311649346576659258296…`. Truncated/rounded forms were used for the individual types. --- ~~I did not any of the `#[unstable]` attributes since I am not aware of their implications.~~ **Edit:** I applied the stability attributes from the surrounding types according to what seemed most likely correct. I believe the `more_float_constants` feature marker is incorrectly applied, but I wasn't sure how to proceed.		2024-06-09 19:16:19 +01:00
..
benches	Write char::DebugEscape sequences using write_str	2024-05-20 10:04:44 +02:00
src	Rollup merge of #125253 - sunsided:feature/FRAC_1_SQRT_PI, r=Mark-Simulacrum	2024-06-09 19:16:19 +01:00
tests	Stabilize error_in_core	2024-06-07 08:30:00 +08:00
Cargo.toml	Remove now outdated comment since we bumped stage0	2024-05-24 08:08:41 +02:00