//! libm in pure Rust

#![no_std]

#![cfg_attr(feature = "unstable", allow(internal_features))]

#![cfg_attr(feature = "unstable", feature(core_intrinsics))]

#![allow(clippy::assign_op_pattern)]

#![allow(clippy::deprecated_cfg_attr)]

#![allow(clippy::eq_op)]

#![allow(clippy::float_cmp)]

#![allow(clippy::int_plus_one)]

#![allow(clippy::many_single_char_names)]

#![allow(clippy::mixed_case_hex_literals)]

#![allow(clippy::needless_return)]

#![allow(clippy::unreadable_literal)]

mod libm_helper;

mod math;

use core::{f32, f64};

pub use libm_helper::*;

pub use self::math::*;

/// Approximate equality with 1 ULP of tolerance

#[doc(hidden)]

#[inline]

pub fn _eqf(a: f32, b: f32) -> Result<(), u32> {

    if a.is_nan() && b.is_nan() {

        Ok(())

    } else {

        let err = (a.to_bits() as i32).wrapping_sub(b.to_bits() as i32).abs();

        if err <= 1 { Ok(()) } else { Err(err as u32) }

    }

}

#[doc(hidden)]

#[inline]

pub fn _eq(a: f64, b: f64) -> Result<(), u64> {

    if a.is_nan() && b.is_nan() {

        Ok(())

    } else {

        let err = (a.to_bits() as i64).wrapping_sub(b.to_bits() as i64).abs();

        if err <= 1 { Ok(()) } else { Err(err as u64) }

    }

}