1 // Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! This module provides constants which are specific to the implementation
12 //! of the `f32` floating point data type. Mathematically significant
13 //! numbers are provided in the `consts` sub-module.
15 //! *[See also the `f32` primitive type](../primitive.f32.html).*
17 #![stable(feature = "rust1", since = "1.0.0")]
18 #![allow(missing_docs)]
28 #[stable(feature = "rust1", since = "1.0.0")]
29 pub use core::f32::{RADIX, MANTISSA_DIGITS, DIGITS, EPSILON};
30 #[stable(feature = "rust1", since = "1.0.0")]
31 pub use core::f32::{MIN_EXP, MAX_EXP, MIN_10_EXP};
32 #[stable(feature = "rust1", since = "1.0.0")]
33 pub use core::f32::{MAX_10_EXP, NAN, INFINITY, NEG_INFINITY};
34 #[stable(feature = "rust1", since = "1.0.0")]
35 pub use core::f32::{MIN, MIN_POSITIVE, MAX};
36 #[stable(feature = "rust1", since = "1.0.0")]
37 pub use core::f32::consts;
41 use libc::{c_float, c_int};
44 pub fn cbrtf(n: c_float) -> c_float;
45 pub fn erff(n: c_float) -> c_float;
46 pub fn erfcf(n: c_float) -> c_float;
47 pub fn expm1f(n: c_float) -> c_float;
48 pub fn fdimf(a: c_float, b: c_float) -> c_float;
49 pub fn fmodf(a: c_float, b: c_float) -> c_float;
50 pub fn ilogbf(n: c_float) -> c_int;
51 pub fn logbf(n: c_float) -> c_float;
52 pub fn log1pf(n: c_float) -> c_float;
53 pub fn modff(n: c_float, iptr: &mut c_float) -> c_float;
54 pub fn nextafterf(x: c_float, y: c_float) -> c_float;
55 pub fn tgammaf(n: c_float) -> c_float;
57 #[cfg_attr(all(windows, target_env = "msvc"), link_name = "__lgammaf_r")]
58 pub fn lgammaf_r(n: c_float, sign: &mut c_int) -> c_float;
59 #[cfg_attr(all(windows, target_env = "msvc"), link_name = "_hypotf")]
60 pub fn hypotf(x: c_float, y: c_float) -> c_float;
63 // See the comments in the `floor` function for why MSVC is special
65 #[cfg(not(target_env = "msvc"))]
67 pub fn acosf(n: c_float) -> c_float;
68 pub fn asinf(n: c_float) -> c_float;
69 pub fn atan2f(a: c_float, b: c_float) -> c_float;
70 pub fn atanf(n: c_float) -> c_float;
71 pub fn coshf(n: c_float) -> c_float;
72 pub fn sinhf(n: c_float) -> c_float;
73 pub fn tanf(n: c_float) -> c_float;
74 pub fn tanhf(n: c_float) -> c_float;
77 #[cfg(target_env = "msvc")]
78 pub use self::shims::*;
79 #[cfg(target_env = "msvc")]
84 pub unsafe fn acosf(n: c_float) -> c_float {
85 f64::acos(n as f64) as c_float
89 pub unsafe fn asinf(n: c_float) -> c_float {
90 f64::asin(n as f64) as c_float
94 pub unsafe fn atan2f(n: c_float, b: c_float) -> c_float {
95 f64::atan2(n as f64, b as f64) as c_float
99 pub unsafe fn atanf(n: c_float) -> c_float {
100 f64::atan(n as f64) as c_float
104 pub unsafe fn coshf(n: c_float) -> c_float {
105 f64::cosh(n as f64) as c_float
109 pub unsafe fn sinhf(n: c_float) -> c_float {
110 f64::sinh(n as f64) as c_float
114 pub unsafe fn tanf(n: c_float) -> c_float {
115 f64::tan(n as f64) as c_float
119 pub unsafe fn tanhf(n: c_float) -> c_float {
120 f64::tanh(n as f64) as c_float
128 /// Returns `true` if this value is `NaN` and false otherwise.
133 /// let nan = f32::NAN;
136 /// assert!(nan.is_nan());
137 /// assert!(!f.is_nan());
139 #[stable(feature = "rust1", since = "1.0.0")]
141 pub fn is_nan(self) -> bool { num::Float::is_nan(self) }
143 /// Returns `true` if this value is positive infinity or negative infinity and
150 /// let inf = f32::INFINITY;
151 /// let neg_inf = f32::NEG_INFINITY;
152 /// let nan = f32::NAN;
154 /// assert!(!f.is_infinite());
155 /// assert!(!nan.is_infinite());
157 /// assert!(inf.is_infinite());
158 /// assert!(neg_inf.is_infinite());
160 #[stable(feature = "rust1", since = "1.0.0")]
162 pub fn is_infinite(self) -> bool { num::Float::is_infinite(self) }
164 /// Returns `true` if this number is neither infinite nor `NaN`.
170 /// let inf = f32::INFINITY;
171 /// let neg_inf = f32::NEG_INFINITY;
172 /// let nan = f32::NAN;
174 /// assert!(f.is_finite());
176 /// assert!(!nan.is_finite());
177 /// assert!(!inf.is_finite());
178 /// assert!(!neg_inf.is_finite());
180 #[stable(feature = "rust1", since = "1.0.0")]
182 pub fn is_finite(self) -> bool { num::Float::is_finite(self) }
184 /// Returns `true` if the number is neither zero, infinite,
185 /// [subnormal][subnormal], or `NaN`.
190 /// let min = f32::MIN_POSITIVE; // 1.17549435e-38f32
191 /// let max = f32::MAX;
192 /// let lower_than_min = 1.0e-40_f32;
193 /// let zero = 0.0_f32;
195 /// assert!(min.is_normal());
196 /// assert!(max.is_normal());
198 /// assert!(!zero.is_normal());
199 /// assert!(!f32::NAN.is_normal());
200 /// assert!(!f32::INFINITY.is_normal());
201 /// // Values between `0` and `min` are Subnormal.
202 /// assert!(!lower_than_min.is_normal());
204 /// [subnormal]: https://en.wikipedia.org/wiki/Denormal_number
205 #[stable(feature = "rust1", since = "1.0.0")]
207 pub fn is_normal(self) -> bool { num::Float::is_normal(self) }
209 /// Returns the floating point category of the number. If only one property
210 /// is going to be tested, it is generally faster to use the specific
211 /// predicate instead.
214 /// use std::num::FpCategory;
217 /// let num = 12.4_f32;
218 /// let inf = f32::INFINITY;
220 /// assert_eq!(num.classify(), FpCategory::Normal);
221 /// assert_eq!(inf.classify(), FpCategory::Infinite);
223 #[stable(feature = "rust1", since = "1.0.0")]
225 pub fn classify(self) -> FpCategory { num::Float::classify(self) }
227 /// Returns the largest integer less than or equal to a number.
230 /// let f = 3.99_f32;
233 /// assert_eq!(f.floor(), 3.0);
234 /// assert_eq!(g.floor(), 3.0);
236 #[stable(feature = "rust1", since = "1.0.0")]
238 pub fn floor(self) -> f32 {
239 // On MSVC LLVM will lower many math intrinsics to a call to the
240 // corresponding function. On MSVC, however, many of these functions
241 // aren't actually available as symbols to call, but rather they are all
242 // `static inline` functions in header files. This means that from a C
243 // perspective it's "compatible", but not so much from an ABI
244 // perspective (which we're worried about).
246 // The inline header functions always just cast to a f64 and do their
247 // operation, so we do that here as well, but only for MSVC targets.
249 // Note that there are many MSVC-specific float operations which
250 // redirect to this comment, so `floorf` is just one case of a missing
251 // function on MSVC, but there are many others elsewhere.
252 #[cfg(target_env = "msvc")]
253 return (self as f64).floor() as f32;
254 #[cfg(not(target_env = "msvc"))]
255 return unsafe { intrinsics::floorf32(self) };
258 /// Returns the smallest integer greater than or equal to a number.
261 /// let f = 3.01_f32;
264 /// assert_eq!(f.ceil(), 4.0);
265 /// assert_eq!(g.ceil(), 4.0);
267 #[stable(feature = "rust1", since = "1.0.0")]
269 pub fn ceil(self) -> f32 {
270 // see notes above in `floor`
271 #[cfg(target_env = "msvc")]
272 return (self as f64).ceil() as f32;
273 #[cfg(not(target_env = "msvc"))]
274 return unsafe { intrinsics::ceilf32(self) };
277 /// Returns the nearest integer to a number. Round half-way cases away from
282 /// let g = -3.3_f32;
284 /// assert_eq!(f.round(), 3.0);
285 /// assert_eq!(g.round(), -3.0);
287 #[stable(feature = "rust1", since = "1.0.0")]
289 pub fn round(self) -> f32 {
290 unsafe { intrinsics::roundf32(self) }
293 /// Returns the integer part of a number.
297 /// let g = -3.7_f32;
299 /// assert_eq!(f.trunc(), 3.0);
300 /// assert_eq!(g.trunc(), -3.0);
302 #[stable(feature = "rust1", since = "1.0.0")]
304 pub fn trunc(self) -> f32 {
305 unsafe { intrinsics::truncf32(self) }
308 /// Returns the fractional part of a number.
314 /// let y = -3.5_f32;
315 /// let abs_difference_x = (x.fract() - 0.5).abs();
316 /// let abs_difference_y = (y.fract() - (-0.5)).abs();
318 /// assert!(abs_difference_x <= f32::EPSILON);
319 /// assert!(abs_difference_y <= f32::EPSILON);
321 #[stable(feature = "rust1", since = "1.0.0")]
323 pub fn fract(self) -> f32 { self - self.trunc() }
325 /// Computes the absolute value of `self`. Returns `NAN` if the
332 /// let y = -3.5_f32;
334 /// let abs_difference_x = (x.abs() - x).abs();
335 /// let abs_difference_y = (y.abs() - (-y)).abs();
337 /// assert!(abs_difference_x <= f32::EPSILON);
338 /// assert!(abs_difference_y <= f32::EPSILON);
340 /// assert!(f32::NAN.abs().is_nan());
342 #[stable(feature = "rust1", since = "1.0.0")]
344 pub fn abs(self) -> f32 { num::Float::abs(self) }
346 /// Returns a number that represents the sign of `self`.
348 /// - `1.0` if the number is positive, `+0.0` or `INFINITY`
349 /// - `-1.0` if the number is negative, `-0.0` or `NEG_INFINITY`
350 /// - `NAN` if the number is `NAN`
357 /// assert_eq!(f.signum(), 1.0);
358 /// assert_eq!(f32::NEG_INFINITY.signum(), -1.0);
360 /// assert!(f32::NAN.signum().is_nan());
362 #[stable(feature = "rust1", since = "1.0.0")]
364 pub fn signum(self) -> f32 { num::Float::signum(self) }
366 /// Returns `true` if `self`'s sign bit is positive, including
367 /// `+0.0` and `INFINITY`.
372 /// let nan = f32::NAN;
374 /// let g = -7.0_f32;
376 /// assert!(f.is_sign_positive());
377 /// assert!(!g.is_sign_positive());
378 /// // Requires both tests to determine if is `NaN`
379 /// assert!(!nan.is_sign_positive() && !nan.is_sign_negative());
381 #[stable(feature = "rust1", since = "1.0.0")]
383 pub fn is_sign_positive(self) -> bool { num::Float::is_sign_positive(self) }
385 /// Returns `true` if `self`'s sign is negative, including `-0.0`
386 /// and `NEG_INFINITY`.
391 /// let nan = f32::NAN;
395 /// assert!(!f.is_sign_negative());
396 /// assert!(g.is_sign_negative());
397 /// // Requires both tests to determine if is `NaN`.
398 /// assert!(!nan.is_sign_positive() && !nan.is_sign_negative());
400 #[stable(feature = "rust1", since = "1.0.0")]
402 pub fn is_sign_negative(self) -> bool { num::Float::is_sign_negative(self) }
404 /// Fused multiply-add. Computes `(self * a) + b` with only one rounding
405 /// error. This produces a more accurate result with better performance than
406 /// a separate multiplication operation followed by an add.
411 /// let m = 10.0_f32;
413 /// let b = 60.0_f32;
416 /// let abs_difference = (m.mul_add(x, b) - (m*x + b)).abs();
418 /// assert!(abs_difference <= f32::EPSILON);
420 #[stable(feature = "rust1", since = "1.0.0")]
422 pub fn mul_add(self, a: f32, b: f32) -> f32 {
423 unsafe { intrinsics::fmaf32(self, a, b) }
426 /// Takes the reciprocal (inverse) of a number, `1/x`.
432 /// let abs_difference = (x.recip() - (1.0/x)).abs();
434 /// assert!(abs_difference <= f32::EPSILON);
436 #[stable(feature = "rust1", since = "1.0.0")]
438 pub fn recip(self) -> f32 { num::Float::recip(self) }
440 /// Raises a number to an integer power.
442 /// Using this function is generally faster than using `powf`
448 /// let abs_difference = (x.powi(2) - x*x).abs();
450 /// assert!(abs_difference <= f32::EPSILON);
452 #[stable(feature = "rust1", since = "1.0.0")]
454 pub fn powi(self, n: i32) -> f32 { num::Float::powi(self, n) }
456 /// Raises a number to a floating point power.
462 /// let abs_difference = (x.powf(2.0) - x*x).abs();
464 /// assert!(abs_difference <= f32::EPSILON);
466 #[stable(feature = "rust1", since = "1.0.0")]
468 pub fn powf(self, n: f32) -> f32 {
469 // see notes above in `floor`
470 #[cfg(target_env = "msvc")]
471 return (self as f64).powf(n as f64) as f32;
472 #[cfg(not(target_env = "msvc"))]
473 return unsafe { intrinsics::powf32(self, n) };
476 /// Takes the square root of a number.
478 /// Returns NaN if `self` is a negative number.
483 /// let positive = 4.0_f32;
484 /// let negative = -4.0_f32;
486 /// let abs_difference = (positive.sqrt() - 2.0).abs();
488 /// assert!(abs_difference <= f32::EPSILON);
489 /// assert!(negative.sqrt().is_nan());
491 #[stable(feature = "rust1", since = "1.0.0")]
493 pub fn sqrt(self) -> f32 {
497 unsafe { intrinsics::sqrtf32(self) }
501 /// Returns `e^(self)`, (the exponential function).
506 /// let one = 1.0f32;
508 /// let e = one.exp();
510 /// // ln(e) - 1 == 0
511 /// let abs_difference = (e.ln() - 1.0).abs();
513 /// assert!(abs_difference <= f32::EPSILON);
515 #[stable(feature = "rust1", since = "1.0.0")]
517 pub fn exp(self) -> f32 {
518 // see notes above in `floor`
519 #[cfg(target_env = "msvc")]
520 return (self as f64).exp() as f32;
521 #[cfg(not(target_env = "msvc"))]
522 return unsafe { intrinsics::expf32(self) };
525 /// Returns `2^(self)`.
533 /// let abs_difference = (f.exp2() - 4.0).abs();
535 /// assert!(abs_difference <= f32::EPSILON);
537 #[stable(feature = "rust1", since = "1.0.0")]
539 pub fn exp2(self) -> f32 {
540 unsafe { intrinsics::exp2f32(self) }
543 /// Returns the natural logarithm of the number.
548 /// let one = 1.0f32;
550 /// let e = one.exp();
552 /// // ln(e) - 1 == 0
553 /// let abs_difference = (e.ln() - 1.0).abs();
555 /// assert!(abs_difference <= f32::EPSILON);
557 #[stable(feature = "rust1", since = "1.0.0")]
559 pub fn ln(self) -> f32 {
560 // see notes above in `floor`
561 #[cfg(target_env = "msvc")]
562 return (self as f64).ln() as f32;
563 #[cfg(not(target_env = "msvc"))]
564 return unsafe { intrinsics::logf32(self) };
567 /// Returns the logarithm of the number with respect to an arbitrary base.
572 /// let ten = 10.0f32;
573 /// let two = 2.0f32;
575 /// // log10(10) - 1 == 0
576 /// let abs_difference_10 = (ten.log(10.0) - 1.0).abs();
578 /// // log2(2) - 1 == 0
579 /// let abs_difference_2 = (two.log(2.0) - 1.0).abs();
581 /// assert!(abs_difference_10 <= f32::EPSILON);
582 /// assert!(abs_difference_2 <= f32::EPSILON);
584 #[stable(feature = "rust1", since = "1.0.0")]
586 pub fn log(self, base: f32) -> f32 { self.ln() / base.ln() }
588 /// Returns the base 2 logarithm of the number.
593 /// let two = 2.0f32;
595 /// // log2(2) - 1 == 0
596 /// let abs_difference = (two.log2() - 1.0).abs();
598 /// assert!(abs_difference <= f32::EPSILON);
600 #[stable(feature = "rust1", since = "1.0.0")]
602 pub fn log2(self) -> f32 {
603 #[cfg(target_os = "android")]
604 return ::sys::android::log2f32(self);
605 #[cfg(not(target_os = "android"))]
606 return unsafe { intrinsics::log2f32(self) };
609 /// Returns the base 10 logarithm of the number.
614 /// let ten = 10.0f32;
616 /// // log10(10) - 1 == 0
617 /// let abs_difference = (ten.log10() - 1.0).abs();
619 /// assert!(abs_difference <= f32::EPSILON);
621 #[stable(feature = "rust1", since = "1.0.0")]
623 pub fn log10(self) -> f32 {
624 // see notes above in `floor`
625 #[cfg(target_env = "msvc")]
626 return (self as f64).log10() as f32;
627 #[cfg(not(target_env = "msvc"))]
628 return unsafe { intrinsics::log10f32(self) };
631 /// Converts radians to degrees.
634 /// use std::f32::{self, consts};
636 /// let angle = consts::PI;
638 /// let abs_difference = (angle.to_degrees() - 180.0).abs();
640 /// assert!(abs_difference <= f32::EPSILON);
642 #[stable(feature = "f32_deg_rad_conversions", since="1.7.0")]
644 pub fn to_degrees(self) -> f32 { num::Float::to_degrees(self) }
646 /// Converts degrees to radians.
649 /// use std::f32::{self, consts};
651 /// let angle = 180.0f32;
653 /// let abs_difference = (angle.to_radians() - consts::PI).abs();
655 /// assert!(abs_difference <= f32::EPSILON);
657 #[stable(feature = "f32_deg_rad_conversions", since="1.7.0")]
659 pub fn to_radians(self) -> f32 { num::Float::to_radians(self) }
661 /// Returns the maximum of the two numbers.
667 /// assert_eq!(x.max(y), y);
670 /// If one of the arguments is NaN, then the other argument is returned.
671 #[stable(feature = "rust1", since = "1.0.0")]
673 pub fn max(self, other: f32) -> f32 {
674 num::Float::max(self, other)
677 /// Returns the minimum of the two numbers.
683 /// assert_eq!(x.min(y), x);
686 /// If one of the arguments is NaN, then the other argument is returned.
687 #[stable(feature = "rust1", since = "1.0.0")]
689 pub fn min(self, other: f32) -> f32 {
690 num::Float::min(self, other)
693 /// The positive difference of two numbers.
695 /// * If `self <= other`: `0:0`
696 /// * Else: `self - other`
704 /// let abs_difference_x = (x.abs_sub(1.0) - 2.0).abs();
705 /// let abs_difference_y = (y.abs_sub(1.0) - 0.0).abs();
707 /// assert!(abs_difference_x <= f32::EPSILON);
708 /// assert!(abs_difference_y <= f32::EPSILON);
710 #[stable(feature = "rust1", since = "1.0.0")]
712 #[rustc_deprecated(since = "1.10.0",
713 reason = "you probably meant `(self - other).abs()`: \
714 this operation is `(self - other).max(0.0)` (also \
715 known as `fdimf` in C). If you truly need the positive \
716 difference, consider using that expression or the C function \
717 `fdimf`, depending on how you wish to handle NaN (please consider \
718 filing an issue describing your use-case too).")]
719 pub fn abs_sub(self, other: f32) -> f32 {
720 unsafe { cmath::fdimf(self, other) }
723 /// Takes the cubic root of a number.
730 /// // x^(1/3) - 2 == 0
731 /// let abs_difference = (x.cbrt() - 2.0).abs();
733 /// assert!(abs_difference <= f32::EPSILON);
735 #[stable(feature = "rust1", since = "1.0.0")]
737 pub fn cbrt(self) -> f32 {
738 unsafe { cmath::cbrtf(self) }
741 /// Calculates the length of the hypotenuse of a right-angle triangle given
742 /// legs of length `x` and `y`.
750 /// // sqrt(x^2 + y^2)
751 /// let abs_difference = (x.hypot(y) - (x.powi(2) + y.powi(2)).sqrt()).abs();
753 /// assert!(abs_difference <= f32::EPSILON);
755 #[stable(feature = "rust1", since = "1.0.0")]
757 pub fn hypot(self, other: f32) -> f32 {
758 unsafe { cmath::hypotf(self, other) }
761 /// Computes the sine of a number (in radians).
766 /// let x = f32::consts::PI/2.0;
768 /// let abs_difference = (x.sin() - 1.0).abs();
770 /// assert!(abs_difference <= f32::EPSILON);
772 #[stable(feature = "rust1", since = "1.0.0")]
774 pub fn sin(self) -> f32 {
775 // see notes in `core::f32::Float::floor`
776 #[cfg(target_env = "msvc")]
777 return (self as f64).sin() as f32;
778 #[cfg(not(target_env = "msvc"))]
779 return unsafe { intrinsics::sinf32(self) };
782 /// Computes the cosine of a number (in radians).
787 /// let x = 2.0*f32::consts::PI;
789 /// let abs_difference = (x.cos() - 1.0).abs();
791 /// assert!(abs_difference <= f32::EPSILON);
793 #[stable(feature = "rust1", since = "1.0.0")]
795 pub fn cos(self) -> f32 {
796 // see notes in `core::f32::Float::floor`
797 #[cfg(target_env = "msvc")]
798 return (self as f64).cos() as f32;
799 #[cfg(not(target_env = "msvc"))]
800 return unsafe { intrinsics::cosf32(self) };
803 /// Computes the tangent of a number (in radians).
808 /// let x = f32::consts::PI / 4.0;
809 /// let abs_difference = (x.tan() - 1.0).abs();
811 /// assert!(abs_difference <= f32::EPSILON);
813 #[stable(feature = "rust1", since = "1.0.0")]
815 pub fn tan(self) -> f32 {
816 unsafe { cmath::tanf(self) }
819 /// Computes the arcsine of a number. Return value is in radians in
820 /// the range [-pi/2, pi/2] or NaN if the number is outside the range
826 /// let f = f32::consts::PI / 2.0;
828 /// // asin(sin(pi/2))
829 /// let abs_difference = (f.sin().asin() - f32::consts::PI / 2.0).abs();
831 /// assert!(abs_difference <= f32::EPSILON);
833 #[stable(feature = "rust1", since = "1.0.0")]
835 pub fn asin(self) -> f32 {
836 unsafe { cmath::asinf(self) }
839 /// Computes the arccosine of a number. Return value is in radians in
840 /// the range [0, pi] or NaN if the number is outside the range
846 /// let f = f32::consts::PI / 4.0;
848 /// // acos(cos(pi/4))
849 /// let abs_difference = (f.cos().acos() - f32::consts::PI / 4.0).abs();
851 /// assert!(abs_difference <= f32::EPSILON);
853 #[stable(feature = "rust1", since = "1.0.0")]
855 pub fn acos(self) -> f32 {
856 unsafe { cmath::acosf(self) }
859 /// Computes the arctangent of a number. Return value is in radians in the
860 /// range [-pi/2, pi/2];
868 /// let abs_difference = (f.tan().atan() - 1.0).abs();
870 /// assert!(abs_difference <= f32::EPSILON);
872 #[stable(feature = "rust1", since = "1.0.0")]
874 pub fn atan(self) -> f32 {
875 unsafe { cmath::atanf(self) }
878 /// Computes the four quadrant arctangent of `self` (`y`) and `other` (`x`).
880 /// * `x = 0`, `y = 0`: `0`
881 /// * `x >= 0`: `arctan(y/x)` -> `[-pi/2, pi/2]`
882 /// * `y >= 0`: `arctan(y/x) + pi` -> `(pi/2, pi]`
883 /// * `y < 0`: `arctan(y/x) - pi` -> `(-pi, -pi/2)`
888 /// let pi = f32::consts::PI;
889 /// // All angles from horizontal right (+x)
890 /// // 45 deg counter-clockwise
892 /// let y1 = -3.0f32;
894 /// // 135 deg clockwise
895 /// let x2 = -3.0f32;
898 /// let abs_difference_1 = (y1.atan2(x1) - (-pi/4.0)).abs();
899 /// let abs_difference_2 = (y2.atan2(x2) - 3.0*pi/4.0).abs();
901 /// assert!(abs_difference_1 <= f32::EPSILON);
902 /// assert!(abs_difference_2 <= f32::EPSILON);
904 #[stable(feature = "rust1", since = "1.0.0")]
906 pub fn atan2(self, other: f32) -> f32 {
907 unsafe { cmath::atan2f(self, other) }
910 /// Simultaneously computes the sine and cosine of the number, `x`. Returns
911 /// `(sin(x), cos(x))`.
916 /// let x = f32::consts::PI/4.0;
917 /// let f = x.sin_cos();
919 /// let abs_difference_0 = (f.0 - x.sin()).abs();
920 /// let abs_difference_1 = (f.1 - x.cos()).abs();
922 /// assert!(abs_difference_0 <= f32::EPSILON);
923 /// assert!(abs_difference_1 <= f32::EPSILON);
925 #[stable(feature = "rust1", since = "1.0.0")]
927 pub fn sin_cos(self) -> (f32, f32) {
928 (self.sin(), self.cos())
931 /// Returns `e^(self) - 1` in a way that is accurate even if the
932 /// number is close to zero.
940 /// let abs_difference = (x.ln().exp_m1() - 5.0).abs();
942 /// assert!(abs_difference <= f32::EPSILON);
944 #[stable(feature = "rust1", since = "1.0.0")]
946 pub fn exp_m1(self) -> f32 {
947 unsafe { cmath::expm1f(self) }
950 /// Returns `ln(1+n)` (natural logarithm) more accurately than if
951 /// the operations were performed separately.
956 /// let x = f32::consts::E - 1.0;
958 /// // ln(1 + (e - 1)) == ln(e) == 1
959 /// let abs_difference = (x.ln_1p() - 1.0).abs();
961 /// assert!(abs_difference <= f32::EPSILON);
963 #[stable(feature = "rust1", since = "1.0.0")]
965 pub fn ln_1p(self) -> f32 {
966 unsafe { cmath::log1pf(self) }
969 /// Hyperbolic sine function.
974 /// let e = f32::consts::E;
977 /// let f = x.sinh();
978 /// // Solving sinh() at 1 gives `(e^2-1)/(2e)`
979 /// let g = (e*e - 1.0)/(2.0*e);
980 /// let abs_difference = (f - g).abs();
982 /// assert!(abs_difference <= f32::EPSILON);
984 #[stable(feature = "rust1", since = "1.0.0")]
986 pub fn sinh(self) -> f32 {
987 unsafe { cmath::sinhf(self) }
990 /// Hyperbolic cosine function.
995 /// let e = f32::consts::E;
997 /// let f = x.cosh();
998 /// // Solving cosh() at 1 gives this result
999 /// let g = (e*e + 1.0)/(2.0*e);
1000 /// let abs_difference = (f - g).abs();
1003 /// assert!(abs_difference <= f32::EPSILON);
1005 #[stable(feature = "rust1", since = "1.0.0")]
1007 pub fn cosh(self) -> f32 {
1008 unsafe { cmath::coshf(self) }
1011 /// Hyperbolic tangent function.
1016 /// let e = f32::consts::E;
1019 /// let f = x.tanh();
1020 /// // Solving tanh() at 1 gives `(1 - e^(-2))/(1 + e^(-2))`
1021 /// let g = (1.0 - e.powi(-2))/(1.0 + e.powi(-2));
1022 /// let abs_difference = (f - g).abs();
1024 /// assert!(abs_difference <= f32::EPSILON);
1026 #[stable(feature = "rust1", since = "1.0.0")]
1028 pub fn tanh(self) -> f32 {
1029 unsafe { cmath::tanhf(self) }
1032 /// Inverse hyperbolic sine function.
1038 /// let f = x.sinh().asinh();
1040 /// let abs_difference = (f - x).abs();
1042 /// assert!(abs_difference <= f32::EPSILON);
1044 #[stable(feature = "rust1", since = "1.0.0")]
1046 pub fn asinh(self) -> f32 {
1047 if self == NEG_INFINITY {
1050 (self + ((self * self) + 1.0).sqrt()).ln()
1054 /// Inverse hyperbolic cosine function.
1060 /// let f = x.cosh().acosh();
1062 /// let abs_difference = (f - x).abs();
1064 /// assert!(abs_difference <= f32::EPSILON);
1066 #[stable(feature = "rust1", since = "1.0.0")]
1068 pub fn acosh(self) -> f32 {
1070 x if x < 1.0 => ::f32::NAN,
1071 x => (x + ((x * x) - 1.0).sqrt()).ln(),
1075 /// Inverse hyperbolic tangent function.
1080 /// let e = f32::consts::E;
1081 /// let f = e.tanh().atanh();
1083 /// let abs_difference = (f - e).abs();
1085 /// assert!(abs_difference <= 1e-5);
1087 #[stable(feature = "rust1", since = "1.0.0")]
1089 pub fn atanh(self) -> f32 {
1090 0.5 * ((2.0 * self) / (1.0 - self)).ln_1p()
1093 /// Raw transmutation to `u32`.
1095 /// Converts the `f32` into its raw memory representation,
1096 /// similar to the `transmute` function.
1098 /// Note that this function is distinct from casting.
1103 /// #![feature(float_bits_conv)]
1104 /// assert_ne!((1f32).to_bits(), 1f32 as u32); // to_bits() is not casting!
1105 /// assert_eq!((12.5f32).to_bits(), 0x41480000);
1108 #[unstable(feature = "float_bits_conv", reason = "recently added", issue = "40470")]
1110 pub fn to_bits(self) -> u32 {
1111 unsafe { ::mem::transmute(self) }
1114 /// Raw transmutation from `u32`.
1116 /// Converts the given `u32` containing the float's raw memory
1117 /// representation into the `f32` type, similar to the
1118 /// `transmute` function.
1120 /// There is only one difference to a bare `transmute`:
1121 /// Due to the implications onto Rust's safety promises being
1122 /// uncertain, if the representation of a signaling NaN "sNaN" float
1123 /// is passed to the function, the implementation is allowed to
1124 /// return a quiet NaN instead.
1126 /// Note that this function is distinct from casting.
1131 /// #![feature(float_bits_conv)]
1133 /// let v = f32::from_bits(0x41480000);
1134 /// let difference = (v - 12.5).abs();
1135 /// assert!(difference <= 1e-5);
1136 /// // Example for a signaling NaN value:
1137 /// let snan = 0x7F800001;
1138 /// assert_ne!(f32::from_bits(snan).to_bits(), snan);
1140 #[unstable(feature = "float_bits_conv", reason = "recently added", issue = "40470")]
1142 pub fn from_bits(mut v: u32) -> Self {
1143 const EXP_MASK: u32 = 0x7F800000;
1144 const QNAN_MASK: u32 = 0x00400000;
1145 const FRACT_MASK: u32 = 0x007FFFFF;
1146 if v & EXP_MASK == EXP_MASK && v & FRACT_MASK != 0 {
1147 // If we have a NaN value, we
1148 // convert signaling NaN values to quiet NaN
1149 // by setting the the highest bit of the fraction
1152 unsafe { ::mem::transmute(v) }
1161 use num::FpCategory as Fp;
1165 test_num(10f32, 2f32);
1170 assert_eq!(NAN.min(2.0), 2.0);
1171 assert_eq!(2.0f32.min(NAN), 2.0);
1176 assert_eq!(NAN.max(2.0), 2.0);
1177 assert_eq!(2.0f32.max(NAN), 2.0);
1182 let nan: f32 = f32::NAN;
1183 assert!(nan.is_nan());
1184 assert!(!nan.is_infinite());
1185 assert!(!nan.is_finite());
1186 assert!(!nan.is_normal());
1187 assert!(!nan.is_sign_positive());
1188 assert!(!nan.is_sign_negative());
1189 assert_eq!(Fp::Nan, nan.classify());
1193 fn test_infinity() {
1194 let inf: f32 = f32::INFINITY;
1195 assert!(inf.is_infinite());
1196 assert!(!inf.is_finite());
1197 assert!(inf.is_sign_positive());
1198 assert!(!inf.is_sign_negative());
1199 assert!(!inf.is_nan());
1200 assert!(!inf.is_normal());
1201 assert_eq!(Fp::Infinite, inf.classify());
1205 fn test_neg_infinity() {
1206 let neg_inf: f32 = f32::NEG_INFINITY;
1207 assert!(neg_inf.is_infinite());
1208 assert!(!neg_inf.is_finite());
1209 assert!(!neg_inf.is_sign_positive());
1210 assert!(neg_inf.is_sign_negative());
1211 assert!(!neg_inf.is_nan());
1212 assert!(!neg_inf.is_normal());
1213 assert_eq!(Fp::Infinite, neg_inf.classify());
1218 let zero: f32 = 0.0f32;
1219 assert_eq!(0.0, zero);
1220 assert!(!zero.is_infinite());
1221 assert!(zero.is_finite());
1222 assert!(zero.is_sign_positive());
1223 assert!(!zero.is_sign_negative());
1224 assert!(!zero.is_nan());
1225 assert!(!zero.is_normal());
1226 assert_eq!(Fp::Zero, zero.classify());
1230 fn test_neg_zero() {
1231 let neg_zero: f32 = -0.0;
1232 assert_eq!(0.0, neg_zero);
1233 assert!(!neg_zero.is_infinite());
1234 assert!(neg_zero.is_finite());
1235 assert!(!neg_zero.is_sign_positive());
1236 assert!(neg_zero.is_sign_negative());
1237 assert!(!neg_zero.is_nan());
1238 assert!(!neg_zero.is_normal());
1239 assert_eq!(Fp::Zero, neg_zero.classify());
1244 let one: f32 = 1.0f32;
1245 assert_eq!(1.0, one);
1246 assert!(!one.is_infinite());
1247 assert!(one.is_finite());
1248 assert!(one.is_sign_positive());
1249 assert!(!one.is_sign_negative());
1250 assert!(!one.is_nan());
1251 assert!(one.is_normal());
1252 assert_eq!(Fp::Normal, one.classify());
1257 let nan: f32 = f32::NAN;
1258 let inf: f32 = f32::INFINITY;
1259 let neg_inf: f32 = f32::NEG_INFINITY;
1260 assert!(nan.is_nan());
1261 assert!(!0.0f32.is_nan());
1262 assert!(!5.3f32.is_nan());
1263 assert!(!(-10.732f32).is_nan());
1264 assert!(!inf.is_nan());
1265 assert!(!neg_inf.is_nan());
1269 fn test_is_infinite() {
1270 let nan: f32 = f32::NAN;
1271 let inf: f32 = f32::INFINITY;
1272 let neg_inf: f32 = f32::NEG_INFINITY;
1273 assert!(!nan.is_infinite());
1274 assert!(inf.is_infinite());
1275 assert!(neg_inf.is_infinite());
1276 assert!(!0.0f32.is_infinite());
1277 assert!(!42.8f32.is_infinite());
1278 assert!(!(-109.2f32).is_infinite());
1282 fn test_is_finite() {
1283 let nan: f32 = f32::NAN;
1284 let inf: f32 = f32::INFINITY;
1285 let neg_inf: f32 = f32::NEG_INFINITY;
1286 assert!(!nan.is_finite());
1287 assert!(!inf.is_finite());
1288 assert!(!neg_inf.is_finite());
1289 assert!(0.0f32.is_finite());
1290 assert!(42.8f32.is_finite());
1291 assert!((-109.2f32).is_finite());
1295 fn test_is_normal() {
1296 let nan: f32 = f32::NAN;
1297 let inf: f32 = f32::INFINITY;
1298 let neg_inf: f32 = f32::NEG_INFINITY;
1299 let zero: f32 = 0.0f32;
1300 let neg_zero: f32 = -0.0;
1301 assert!(!nan.is_normal());
1302 assert!(!inf.is_normal());
1303 assert!(!neg_inf.is_normal());
1304 assert!(!zero.is_normal());
1305 assert!(!neg_zero.is_normal());
1306 assert!(1f32.is_normal());
1307 assert!(1e-37f32.is_normal());
1308 assert!(!1e-38f32.is_normal());
1312 fn test_classify() {
1313 let nan: f32 = f32::NAN;
1314 let inf: f32 = f32::INFINITY;
1315 let neg_inf: f32 = f32::NEG_INFINITY;
1316 let zero: f32 = 0.0f32;
1317 let neg_zero: f32 = -0.0;
1318 assert_eq!(nan.classify(), Fp::Nan);
1319 assert_eq!(inf.classify(), Fp::Infinite);
1320 assert_eq!(neg_inf.classify(), Fp::Infinite);
1321 assert_eq!(zero.classify(), Fp::Zero);
1322 assert_eq!(neg_zero.classify(), Fp::Zero);
1323 assert_eq!(1f32.classify(), Fp::Normal);
1324 assert_eq!(1e-37f32.classify(), Fp::Normal);
1325 assert_eq!(1e-38f32.classify(), Fp::Subnormal);
1330 assert_approx_eq!(1.0f32.floor(), 1.0f32);
1331 assert_approx_eq!(1.3f32.floor(), 1.0f32);
1332 assert_approx_eq!(1.5f32.floor(), 1.0f32);
1333 assert_approx_eq!(1.7f32.floor(), 1.0f32);
1334 assert_approx_eq!(0.0f32.floor(), 0.0f32);
1335 assert_approx_eq!((-0.0f32).floor(), -0.0f32);
1336 assert_approx_eq!((-1.0f32).floor(), -1.0f32);
1337 assert_approx_eq!((-1.3f32).floor(), -2.0f32);
1338 assert_approx_eq!((-1.5f32).floor(), -2.0f32);
1339 assert_approx_eq!((-1.7f32).floor(), -2.0f32);
1344 assert_approx_eq!(1.0f32.ceil(), 1.0f32);
1345 assert_approx_eq!(1.3f32.ceil(), 2.0f32);
1346 assert_approx_eq!(1.5f32.ceil(), 2.0f32);
1347 assert_approx_eq!(1.7f32.ceil(), 2.0f32);
1348 assert_approx_eq!(0.0f32.ceil(), 0.0f32);
1349 assert_approx_eq!((-0.0f32).ceil(), -0.0f32);
1350 assert_approx_eq!((-1.0f32).ceil(), -1.0f32);
1351 assert_approx_eq!((-1.3f32).ceil(), -1.0f32);
1352 assert_approx_eq!((-1.5f32).ceil(), -1.0f32);
1353 assert_approx_eq!((-1.7f32).ceil(), -1.0f32);
1358 assert_approx_eq!(1.0f32.round(), 1.0f32);
1359 assert_approx_eq!(1.3f32.round(), 1.0f32);
1360 assert_approx_eq!(1.5f32.round(), 2.0f32);
1361 assert_approx_eq!(1.7f32.round(), 2.0f32);
1362 assert_approx_eq!(0.0f32.round(), 0.0f32);
1363 assert_approx_eq!((-0.0f32).round(), -0.0f32);
1364 assert_approx_eq!((-1.0f32).round(), -1.0f32);
1365 assert_approx_eq!((-1.3f32).round(), -1.0f32);
1366 assert_approx_eq!((-1.5f32).round(), -2.0f32);
1367 assert_approx_eq!((-1.7f32).round(), -2.0f32);
1372 assert_approx_eq!(1.0f32.trunc(), 1.0f32);
1373 assert_approx_eq!(1.3f32.trunc(), 1.0f32);
1374 assert_approx_eq!(1.5f32.trunc(), 1.0f32);
1375 assert_approx_eq!(1.7f32.trunc(), 1.0f32);
1376 assert_approx_eq!(0.0f32.trunc(), 0.0f32);
1377 assert_approx_eq!((-0.0f32).trunc(), -0.0f32);
1378 assert_approx_eq!((-1.0f32).trunc(), -1.0f32);
1379 assert_approx_eq!((-1.3f32).trunc(), -1.0f32);
1380 assert_approx_eq!((-1.5f32).trunc(), -1.0f32);
1381 assert_approx_eq!((-1.7f32).trunc(), -1.0f32);
1386 assert_approx_eq!(1.0f32.fract(), 0.0f32);
1387 assert_approx_eq!(1.3f32.fract(), 0.3f32);
1388 assert_approx_eq!(1.5f32.fract(), 0.5f32);
1389 assert_approx_eq!(1.7f32.fract(), 0.7f32);
1390 assert_approx_eq!(0.0f32.fract(), 0.0f32);
1391 assert_approx_eq!((-0.0f32).fract(), -0.0f32);
1392 assert_approx_eq!((-1.0f32).fract(), -0.0f32);
1393 assert_approx_eq!((-1.3f32).fract(), -0.3f32);
1394 assert_approx_eq!((-1.5f32).fract(), -0.5f32);
1395 assert_approx_eq!((-1.7f32).fract(), -0.7f32);
1400 assert_eq!(INFINITY.abs(), INFINITY);
1401 assert_eq!(1f32.abs(), 1f32);
1402 assert_eq!(0f32.abs(), 0f32);
1403 assert_eq!((-0f32).abs(), 0f32);
1404 assert_eq!((-1f32).abs(), 1f32);
1405 assert_eq!(NEG_INFINITY.abs(), INFINITY);
1406 assert_eq!((1f32/NEG_INFINITY).abs(), 0f32);
1407 assert!(NAN.abs().is_nan());
1412 assert_eq!(INFINITY.signum(), 1f32);
1413 assert_eq!(1f32.signum(), 1f32);
1414 assert_eq!(0f32.signum(), 1f32);
1415 assert_eq!((-0f32).signum(), -1f32);
1416 assert_eq!((-1f32).signum(), -1f32);
1417 assert_eq!(NEG_INFINITY.signum(), -1f32);
1418 assert_eq!((1f32/NEG_INFINITY).signum(), -1f32);
1419 assert!(NAN.signum().is_nan());
1423 fn test_is_sign_positive() {
1424 assert!(INFINITY.is_sign_positive());
1425 assert!(1f32.is_sign_positive());
1426 assert!(0f32.is_sign_positive());
1427 assert!(!(-0f32).is_sign_positive());
1428 assert!(!(-1f32).is_sign_positive());
1429 assert!(!NEG_INFINITY.is_sign_positive());
1430 assert!(!(1f32/NEG_INFINITY).is_sign_positive());
1431 assert!(!NAN.is_sign_positive());
1435 fn test_is_sign_negative() {
1436 assert!(!INFINITY.is_sign_negative());
1437 assert!(!1f32.is_sign_negative());
1438 assert!(!0f32.is_sign_negative());
1439 assert!((-0f32).is_sign_negative());
1440 assert!((-1f32).is_sign_negative());
1441 assert!(NEG_INFINITY.is_sign_negative());
1442 assert!((1f32/NEG_INFINITY).is_sign_negative());
1443 assert!(!NAN.is_sign_negative());
1448 let nan: f32 = f32::NAN;
1449 let inf: f32 = f32::INFINITY;
1450 let neg_inf: f32 = f32::NEG_INFINITY;
1451 assert_approx_eq!(12.3f32.mul_add(4.5, 6.7), 62.05);
1452 assert_approx_eq!((-12.3f32).mul_add(-4.5, -6.7), 48.65);
1453 assert_approx_eq!(0.0f32.mul_add(8.9, 1.2), 1.2);
1454 assert_approx_eq!(3.4f32.mul_add(-0.0, 5.6), 5.6);
1455 assert!(nan.mul_add(7.8, 9.0).is_nan());
1456 assert_eq!(inf.mul_add(7.8, 9.0), inf);
1457 assert_eq!(neg_inf.mul_add(7.8, 9.0), neg_inf);
1458 assert_eq!(8.9f32.mul_add(inf, 3.2), inf);
1459 assert_eq!((-3.2f32).mul_add(2.4, neg_inf), neg_inf);
1464 let nan: f32 = f32::NAN;
1465 let inf: f32 = f32::INFINITY;
1466 let neg_inf: f32 = f32::NEG_INFINITY;
1467 assert_eq!(1.0f32.recip(), 1.0);
1468 assert_eq!(2.0f32.recip(), 0.5);
1469 assert_eq!((-0.4f32).recip(), -2.5);
1470 assert_eq!(0.0f32.recip(), inf);
1471 assert!(nan.recip().is_nan());
1472 assert_eq!(inf.recip(), 0.0);
1473 assert_eq!(neg_inf.recip(), 0.0);
1478 let nan: f32 = f32::NAN;
1479 let inf: f32 = f32::INFINITY;
1480 let neg_inf: f32 = f32::NEG_INFINITY;
1481 assert_eq!(1.0f32.powi(1), 1.0);
1482 assert_approx_eq!((-3.1f32).powi(2), 9.61);
1483 assert_approx_eq!(5.9f32.powi(-2), 0.028727);
1484 assert_eq!(8.3f32.powi(0), 1.0);
1485 assert!(nan.powi(2).is_nan());
1486 assert_eq!(inf.powi(3), inf);
1487 assert_eq!(neg_inf.powi(2), inf);
1492 let nan: f32 = f32::NAN;
1493 let inf: f32 = f32::INFINITY;
1494 let neg_inf: f32 = f32::NEG_INFINITY;
1495 assert_eq!(1.0f32.powf(1.0), 1.0);
1496 assert_approx_eq!(3.4f32.powf(4.5), 246.408218);
1497 assert_approx_eq!(2.7f32.powf(-3.2), 0.041652);
1498 assert_approx_eq!((-3.1f32).powf(2.0), 9.61);
1499 assert_approx_eq!(5.9f32.powf(-2.0), 0.028727);
1500 assert_eq!(8.3f32.powf(0.0), 1.0);
1501 assert!(nan.powf(2.0).is_nan());
1502 assert_eq!(inf.powf(2.0), inf);
1503 assert_eq!(neg_inf.powf(3.0), neg_inf);
1507 fn test_sqrt_domain() {
1508 assert!(NAN.sqrt().is_nan());
1509 assert!(NEG_INFINITY.sqrt().is_nan());
1510 assert!((-1.0f32).sqrt().is_nan());
1511 assert_eq!((-0.0f32).sqrt(), -0.0);
1512 assert_eq!(0.0f32.sqrt(), 0.0);
1513 assert_eq!(1.0f32.sqrt(), 1.0);
1514 assert_eq!(INFINITY.sqrt(), INFINITY);
1519 assert_eq!(1.0, 0.0f32.exp());
1520 assert_approx_eq!(2.718282, 1.0f32.exp());
1521 assert_approx_eq!(148.413162, 5.0f32.exp());
1523 let inf: f32 = f32::INFINITY;
1524 let neg_inf: f32 = f32::NEG_INFINITY;
1525 let nan: f32 = f32::NAN;
1526 assert_eq!(inf, inf.exp());
1527 assert_eq!(0.0, neg_inf.exp());
1528 assert!(nan.exp().is_nan());
1533 assert_eq!(32.0, 5.0f32.exp2());
1534 assert_eq!(1.0, 0.0f32.exp2());
1536 let inf: f32 = f32::INFINITY;
1537 let neg_inf: f32 = f32::NEG_INFINITY;
1538 let nan: f32 = f32::NAN;
1539 assert_eq!(inf, inf.exp2());
1540 assert_eq!(0.0, neg_inf.exp2());
1541 assert!(nan.exp2().is_nan());
1546 let nan: f32 = f32::NAN;
1547 let inf: f32 = f32::INFINITY;
1548 let neg_inf: f32 = f32::NEG_INFINITY;
1549 assert_approx_eq!(1.0f32.exp().ln(), 1.0);
1550 assert!(nan.ln().is_nan());
1551 assert_eq!(inf.ln(), inf);
1552 assert!(neg_inf.ln().is_nan());
1553 assert!((-2.3f32).ln().is_nan());
1554 assert_eq!((-0.0f32).ln(), neg_inf);
1555 assert_eq!(0.0f32.ln(), neg_inf);
1556 assert_approx_eq!(4.0f32.ln(), 1.386294);
1561 let nan: f32 = f32::NAN;
1562 let inf: f32 = f32::INFINITY;
1563 let neg_inf: f32 = f32::NEG_INFINITY;
1564 assert_eq!(10.0f32.log(10.0), 1.0);
1565 assert_approx_eq!(2.3f32.log(3.5), 0.664858);
1566 assert_eq!(1.0f32.exp().log(1.0f32.exp()), 1.0);
1567 assert!(1.0f32.log(1.0).is_nan());
1568 assert!(1.0f32.log(-13.9).is_nan());
1569 assert!(nan.log(2.3).is_nan());
1570 assert_eq!(inf.log(10.0), inf);
1571 assert!(neg_inf.log(8.8).is_nan());
1572 assert!((-2.3f32).log(0.1).is_nan());
1573 assert_eq!((-0.0f32).log(2.0), neg_inf);
1574 assert_eq!(0.0f32.log(7.0), neg_inf);
1579 let nan: f32 = f32::NAN;
1580 let inf: f32 = f32::INFINITY;
1581 let neg_inf: f32 = f32::NEG_INFINITY;
1582 assert_approx_eq!(10.0f32.log2(), 3.321928);
1583 assert_approx_eq!(2.3f32.log2(), 1.201634);
1584 assert_approx_eq!(1.0f32.exp().log2(), 1.442695);
1585 assert!(nan.log2().is_nan());
1586 assert_eq!(inf.log2(), inf);
1587 assert!(neg_inf.log2().is_nan());
1588 assert!((-2.3f32).log2().is_nan());
1589 assert_eq!((-0.0f32).log2(), neg_inf);
1590 assert_eq!(0.0f32.log2(), neg_inf);
1595 let nan: f32 = f32::NAN;
1596 let inf: f32 = f32::INFINITY;
1597 let neg_inf: f32 = f32::NEG_INFINITY;
1598 assert_eq!(10.0f32.log10(), 1.0);
1599 assert_approx_eq!(2.3f32.log10(), 0.361728);
1600 assert_approx_eq!(1.0f32.exp().log10(), 0.434294);
1601 assert_eq!(1.0f32.log10(), 0.0);
1602 assert!(nan.log10().is_nan());
1603 assert_eq!(inf.log10(), inf);
1604 assert!(neg_inf.log10().is_nan());
1605 assert!((-2.3f32).log10().is_nan());
1606 assert_eq!((-0.0f32).log10(), neg_inf);
1607 assert_eq!(0.0f32.log10(), neg_inf);
1611 fn test_to_degrees() {
1612 let pi: f32 = consts::PI;
1613 let nan: f32 = f32::NAN;
1614 let inf: f32 = f32::INFINITY;
1615 let neg_inf: f32 = f32::NEG_INFINITY;
1616 assert_eq!(0.0f32.to_degrees(), 0.0);
1617 assert_approx_eq!((-5.8f32).to_degrees(), -332.315521);
1618 assert_eq!(pi.to_degrees(), 180.0);
1619 assert!(nan.to_degrees().is_nan());
1620 assert_eq!(inf.to_degrees(), inf);
1621 assert_eq!(neg_inf.to_degrees(), neg_inf);
1625 fn test_to_radians() {
1626 let pi: f32 = consts::PI;
1627 let nan: f32 = f32::NAN;
1628 let inf: f32 = f32::INFINITY;
1629 let neg_inf: f32 = f32::NEG_INFINITY;
1630 assert_eq!(0.0f32.to_radians(), 0.0);
1631 assert_approx_eq!(154.6f32.to_radians(), 2.698279);
1632 assert_approx_eq!((-332.31f32).to_radians(), -5.799903);
1633 assert_eq!(180.0f32.to_radians(), pi);
1634 assert!(nan.to_radians().is_nan());
1635 assert_eq!(inf.to_radians(), inf);
1636 assert_eq!(neg_inf.to_radians(), neg_inf);
1641 assert_eq!(0.0f32.asinh(), 0.0f32);
1642 assert_eq!((-0.0f32).asinh(), -0.0f32);
1644 let inf: f32 = f32::INFINITY;
1645 let neg_inf: f32 = f32::NEG_INFINITY;
1646 let nan: f32 = f32::NAN;
1647 assert_eq!(inf.asinh(), inf);
1648 assert_eq!(neg_inf.asinh(), neg_inf);
1649 assert!(nan.asinh().is_nan());
1650 assert_approx_eq!(2.0f32.asinh(), 1.443635475178810342493276740273105f32);
1651 assert_approx_eq!((-2.0f32).asinh(), -1.443635475178810342493276740273105f32);
1656 assert_eq!(1.0f32.acosh(), 0.0f32);
1657 assert!(0.999f32.acosh().is_nan());
1659 let inf: f32 = f32::INFINITY;
1660 let neg_inf: f32 = f32::NEG_INFINITY;
1661 let nan: f32 = f32::NAN;
1662 assert_eq!(inf.acosh(), inf);
1663 assert!(neg_inf.acosh().is_nan());
1664 assert!(nan.acosh().is_nan());
1665 assert_approx_eq!(2.0f32.acosh(), 1.31695789692481670862504634730796844f32);
1666 assert_approx_eq!(3.0f32.acosh(), 1.76274717403908605046521864995958461f32);
1671 assert_eq!(0.0f32.atanh(), 0.0f32);
1672 assert_eq!((-0.0f32).atanh(), -0.0f32);
1674 let inf32: f32 = f32::INFINITY;
1675 let neg_inf32: f32 = f32::NEG_INFINITY;
1676 assert_eq!(1.0f32.atanh(), inf32);
1677 assert_eq!((-1.0f32).atanh(), neg_inf32);
1679 assert!(2f64.atanh().atanh().is_nan());
1680 assert!((-2f64).atanh().atanh().is_nan());
1682 let inf64: f32 = f32::INFINITY;
1683 let neg_inf64: f32 = f32::NEG_INFINITY;
1684 let nan32: f32 = f32::NAN;
1685 assert!(inf64.atanh().is_nan());
1686 assert!(neg_inf64.atanh().is_nan());
1687 assert!(nan32.atanh().is_nan());
1689 assert_approx_eq!(0.5f32.atanh(), 0.54930614433405484569762261846126285f32);
1690 assert_approx_eq!((-0.5f32).atanh(), -0.54930614433405484569762261846126285f32);
1694 fn test_real_consts() {
1697 let pi: f32 = consts::PI;
1698 let frac_pi_2: f32 = consts::FRAC_PI_2;
1699 let frac_pi_3: f32 = consts::FRAC_PI_3;
1700 let frac_pi_4: f32 = consts::FRAC_PI_4;
1701 let frac_pi_6: f32 = consts::FRAC_PI_6;
1702 let frac_pi_8: f32 = consts::FRAC_PI_8;
1703 let frac_1_pi: f32 = consts::FRAC_1_PI;
1704 let frac_2_pi: f32 = consts::FRAC_2_PI;
1705 let frac_2_sqrtpi: f32 = consts::FRAC_2_SQRT_PI;
1706 let sqrt2: f32 = consts::SQRT_2;
1707 let frac_1_sqrt2: f32 = consts::FRAC_1_SQRT_2;
1708 let e: f32 = consts::E;
1709 let log2_e: f32 = consts::LOG2_E;
1710 let log10_e: f32 = consts::LOG10_E;
1711 let ln_2: f32 = consts::LN_2;
1712 let ln_10: f32 = consts::LN_10;
1714 assert_approx_eq!(frac_pi_2, pi / 2f32);
1715 assert_approx_eq!(frac_pi_3, pi / 3f32);
1716 assert_approx_eq!(frac_pi_4, pi / 4f32);
1717 assert_approx_eq!(frac_pi_6, pi / 6f32);
1718 assert_approx_eq!(frac_pi_8, pi / 8f32);
1719 assert_approx_eq!(frac_1_pi, 1f32 / pi);
1720 assert_approx_eq!(frac_2_pi, 2f32 / pi);
1721 assert_approx_eq!(frac_2_sqrtpi, 2f32 / pi.sqrt());
1722 assert_approx_eq!(sqrt2, 2f32.sqrt());
1723 assert_approx_eq!(frac_1_sqrt2, 1f32 / 2f32.sqrt());
1724 assert_approx_eq!(log2_e, e.log2());
1725 assert_approx_eq!(log10_e, e.log10());
1726 assert_approx_eq!(ln_2, 2f32.ln());
1727 assert_approx_eq!(ln_10, 10f32.ln());
1731 fn test_float_bits_conv() {
1732 assert_eq!((1f32).to_bits(), 0x3f800000);
1733 assert_eq!((12.5f32).to_bits(), 0x41480000);
1734 assert_eq!((1337f32).to_bits(), 0x44a72000);
1735 assert_eq!((-14.25f32).to_bits(), 0xc1640000);
1736 assert_approx_eq!(f32::from_bits(0x3f800000), 1.0);
1737 assert_approx_eq!(f32::from_bits(0x41480000), 12.5);
1738 assert_approx_eq!(f32::from_bits(0x44a72000), 1337.0);
1739 assert_approx_eq!(f32::from_bits(0xc1640000), -14.25);
1742 fn test_snan_masking() {
1743 let snan: u32 = 0x7F801337;
1744 const PAYLOAD_MASK: u32 = 0x003FFFFF;
1745 const QNAN_MASK: u32 = 0x00400000;
1746 let nan_masked_fl = f32::from_bits(snan);
1747 let nan_masked = nan_masked_fl.to_bits();
1748 // Ensure that signaling NaNs don't stay the same
1749 assert_ne!(nan_masked, snan);
1750 // Ensure that we have a quiet NaN
1751 assert_ne!(nan_masked & QNAN_MASK, 0);
1752 assert!(nan_masked_fl.is_nan());
1753 // Ensure the payload wasn't touched during conversion
1754 assert_eq!(nan_masked & PAYLOAD_MASK, snan & PAYLOAD_MASK);