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rust/src/libstd/num/f32.rs
Alex Crichton c2e3aa37da rustdoc: Create anchor pages for primitive types 
This commit adds support in rustdoc to recognize the `#[doc(primitive = "foo")]`
attribute. This attribute indicates that the current module is the "owner" of
the primitive type `foo`. For rustdoc, this means that the doc-comment for the
module is the doc-comment for the primitive type, plus a signal to all
downstream crates that hyperlinks for primitive types will be directed at the
crate containing the `#[doc]` directive.

Additionally, rustdoc will favor crates closest to the one being documented
which "implements the primitive type". For example, documentation of libcore
links to libcore for primitive types, but documentation for libstd and beyond
all links to libstd for primitive types.

This change involves no compiler modifications, it is purely a rustdoc change.
The landing pages for the primitive types primarily serve to show a list of
implemented traits for the primitive type itself.

The primitive types documented includes both strings and slices in a semi-ad-hoc
way, but in a way that should provide at least somewhat meaningful
documentation.

Closes #14474
2014-05-31 21:59:50 -07:00

790 lines
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// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! Operations and constants for 32-bits floats (`f32` type)
#![allow(missing_doc)]
#![allow(unsigned_negate)]
#![doc(primitive = "f32")]
use prelude::*;
use from_str::FromStr;
use intrinsics;
use libc::c_int;
use num::strconv;
use num;
use string::String;
pub use core::f32::{RADIX, MANTISSA_DIGITS, DIGITS, EPSILON, MIN_VALUE};
pub use core::f32::{MIN_POS_VALUE, MAX_VALUE, MIN_EXP, MAX_EXP, MIN_10_EXP};
pub use core::f32::{MAX_10_EXP, NAN, INFINITY, NEG_INFINITY};
pub use core::f32::consts;
#[allow(dead_code)]
mod cmath {
use libc::{c_float, c_int};
#[link_name = "m"]
extern {
pub fn acosf(n: c_float) -> c_float;
pub fn asinf(n: c_float) -> c_float;
pub fn atanf(n: c_float) -> c_float;
pub fn atan2f(a: c_float, b: c_float) -> c_float;
pub fn cbrtf(n: c_float) -> c_float;
pub fn coshf(n: c_float) -> c_float;
pub fn erff(n: c_float) -> c_float;
pub fn erfcf(n: c_float) -> c_float;
pub fn expm1f(n: c_float) -> c_float;
pub fn fdimf(a: c_float, b: c_float) -> c_float;
pub fn frexpf(n: c_float, value: &mut c_int) -> c_float;
pub fn fmaxf(a: c_float, b: c_float) -> c_float;
pub fn fminf(a: c_float, b: c_float) -> c_float;
pub fn fmodf(a: c_float, b: c_float) -> c_float;
pub fn nextafterf(x: c_float, y: c_float) -> c_float;
pub fn hypotf(x: c_float, y: c_float) -> c_float;
pub fn ldexpf(x: c_float, n: c_int) -> c_float;
pub fn logbf(n: c_float) -> c_float;
pub fn log1pf(n: c_float) -> c_float;
pub fn ilogbf(n: c_float) -> c_int;
pub fn modff(n: c_float, iptr: &mut c_float) -> c_float;
pub fn sinhf(n: c_float) -> c_float;
pub fn tanf(n: c_float) -> c_float;
pub fn tanhf(n: c_float) -> c_float;
pub fn tgammaf(n: c_float) -> c_float;
#[cfg(unix)]
pub fn lgammaf_r(n: c_float, sign: &mut c_int) -> c_float;
#[cfg(windows)]
#[link_name="__lgammaf_r"]
pub fn lgammaf_r(n: c_float, sign: &mut c_int) -> c_float;
}
}
impl FloatMath for f32 {
/// Constructs a floating point number by multiplying `x` by 2 raised to the
/// power of `exp`
#[inline]
fn ldexp(x: f32, exp: int) -> f32 {
unsafe { cmath::ldexpf(x, exp as c_int) }
}
/// Breaks the number into a normalized fraction and a base-2 exponent,
/// satisfying:
///
/// - `self = x * pow(2, exp)`
/// - `0.5 <= abs(x) < 1.0`
#[inline]
fn frexp(self) -> (f32, int) {
unsafe {
let mut exp = 0;
let x = cmath::frexpf(self, &mut exp);
(x, exp as int)
}
}
/// Returns the next representable floating-point value in the direction of
/// `other`.
#[inline]
fn next_after(self, other: f32) -> f32 {
unsafe { cmath::nextafterf(self, other) }
}
#[inline]
fn max(self, other: f32) -> f32 {
unsafe { cmath::fmaxf(self, other) }
}
#[inline]
fn min(self, other: f32) -> f32 {
unsafe { cmath::fminf(self, other) }
}
#[inline]
fn cbrt(self) -> f32 {
unsafe { cmath::cbrtf(self) }
}
#[inline]
fn hypot(self, other: f32) -> f32 {
unsafe { cmath::hypotf(self, other) }
}
#[inline]
fn sin(self) -> f32 {
unsafe { intrinsics::sinf32(self) }
}
#[inline]
fn cos(self) -> f32 {
unsafe { intrinsics::cosf32(self) }
}
#[inline]
fn tan(self) -> f32 {
unsafe { cmath::tanf(self) }
}
#[inline]
fn asin(self) -> f32 {
unsafe { cmath::asinf(self) }
}
#[inline]
fn acos(self) -> f32 {
unsafe { cmath::acosf(self) }
}
#[inline]
fn atan(self) -> f32 {
unsafe { cmath::atanf(self) }
}
#[inline]
fn atan2(self, other: f32) -> f32 {
unsafe { cmath::atan2f(self, other) }
}
/// Simultaneously computes the sine and cosine of the number
#[inline]
fn sin_cos(self) -> (f32, f32) {
(self.sin(), self.cos())
}
/// Returns the exponential of the number, minus `1`, in a way that is
/// accurate even if the number is close to zero
#[inline]
fn exp_m1(self) -> f32 {
unsafe { cmath::expm1f(self) }
}
/// Returns the natural logarithm of the number plus `1` (`ln(1+n)`) more
/// accurately than if the operations were performed separately
#[inline]
fn ln_1p(self) -> f32 {
unsafe { cmath::log1pf(self) }
}
#[inline]
fn sinh(self) -> f32 {
unsafe { cmath::sinhf(self) }
}
#[inline]
fn cosh(self) -> f32 {
unsafe { cmath::coshf(self) }
}
#[inline]
fn tanh(self) -> f32 {
unsafe { cmath::tanhf(self) }
}
/// Inverse hyperbolic sine
///
/// # Returns
///
/// - on success, the inverse hyperbolic sine of `self` will be returned
/// - `self` if `self` is `0.0`, `-0.0`, `INFINITY`, or `NEG_INFINITY`
/// - `NAN` if `self` is `NAN`
#[inline]
fn asinh(self) -> f32 {
match self {
NEG_INFINITY => NEG_INFINITY,
x => (x + ((x * x) + 1.0).sqrt()).ln(),
}
}
/// Inverse hyperbolic cosine
///
/// # Returns
///
/// - on success, the inverse hyperbolic cosine of `self` will be returned
/// - `INFINITY` if `self` is `INFINITY`
/// - `NAN` if `self` is `NAN` or `self < 1.0` (including `NEG_INFINITY`)
#[inline]
fn acosh(self) -> f32 {
match self {
x if x < 1.0 => Float::nan(),
x => (x + ((x * x) - 1.0).sqrt()).ln(),
}
}
/// Inverse hyperbolic tangent
///
/// # Returns
///
/// - on success, the inverse hyperbolic tangent of `self` will be returned
/// - `self` if `self` is `0.0` or `-0.0`
/// - `INFINITY` if `self` is `1.0`
/// - `NEG_INFINITY` if `self` is `-1.0`
/// - `NAN` if the `self` is `NAN` or outside the domain of `-1.0 <= self <= 1.0`
/// (including `INFINITY` and `NEG_INFINITY`)
#[inline]
fn atanh(self) -> f32 {
0.5 * ((2.0 * self) / (1.0 - self)).ln_1p()
}
}
//
// Section: String Conversions
//
/// Converts a float to a string
///
/// # Arguments
///
/// * num - The float value
#[inline]
pub fn to_str(num: f32) -> String {
let (r, _) = strconv::float_to_str_common(
num, 10u, true, strconv::SignNeg, strconv::DigAll, strconv::ExpNone, false);
r
}
/// Converts a float to a string in hexadecimal format
///
/// # Arguments
///
/// * num - The float value
#[inline]
pub fn to_str_hex(num: f32) -> String {
let (r, _) = strconv::float_to_str_common(
num, 16u, true, strconv::SignNeg, strconv::DigAll, strconv::ExpNone, false);
r
}
/// Converts a float to a string in a given radix, and a flag indicating
/// whether it's a special value
///
/// # Arguments
///
/// * num - The float value
/// * radix - The base to use
#[inline]
pub fn to_str_radix_special(num: f32, rdx: uint) -> (String, bool) {
strconv::float_to_str_common(num, rdx, true,
strconv::SignNeg, strconv::DigAll, strconv::ExpNone, false)
}
/// Converts a float to a string with exactly the number of
/// provided significant digits
///
/// # Arguments
///
/// * num - The float value
/// * digits - The number of significant digits
#[inline]
pub fn to_str_exact(num: f32, dig: uint) -> String {
let (r, _) = strconv::float_to_str_common(
num, 10u, true, strconv::SignNeg, strconv::DigExact(dig), strconv::ExpNone, false);
r
}
/// Converts a float to a string with a maximum number of
/// significant digits
///
/// # Arguments
///
/// * num - The float value
/// * digits - The number of significant digits
#[inline]
pub fn to_str_digits(num: f32, dig: uint) -> String {
let (r, _) = strconv::float_to_str_common(
num, 10u, true, strconv::SignNeg, strconv::DigMax(dig), strconv::ExpNone, false);
r
}
/// Converts a float to a string using the exponential notation with exactly the number of
/// provided digits after the decimal point in the significand
///
/// # Arguments
///
/// * num - The float value
/// * digits - The number of digits after the decimal point
/// * upper - Use `E` instead of `e` for the exponent sign
#[inline]
pub fn to_str_exp_exact(num: f32, dig: uint, upper: bool) -> String {
let (r, _) = strconv::float_to_str_common(
num, 10u, true, strconv::SignNeg, strconv::DigExact(dig), strconv::ExpDec, upper);
r
}
/// Converts a float to a string using the exponential notation with the maximum number of
/// digits after the decimal point in the significand
///
/// # Arguments
///
/// * num - The float value
/// * digits - The number of digits after the decimal point
/// * upper - Use `E` instead of `e` for the exponent sign
#[inline]
pub fn to_str_exp_digits(num: f32, dig: uint, upper: bool) -> String {
let (r, _) = strconv::float_to_str_common(
num, 10u, true, strconv::SignNeg, strconv::DigMax(dig), strconv::ExpDec, upper);
r
}
impl num::ToStrRadix for f32 {
/// Converts a float to a string in a given radix
///
/// # Arguments
///
/// * num - The float value
/// * radix - The base to use
///
/// # Failure
///
/// Fails if called on a special value like `inf`, `-inf` or `NaN` due to
/// possible misinterpretation of the result at higher bases. If those values
/// are expected, use `to_str_radix_special()` instead.
#[inline]
fn to_str_radix(&self, rdx: uint) -> String {
let (r, special) = strconv::float_to_str_common(
*self, rdx, true, strconv::SignNeg, strconv::DigAll, strconv::ExpNone, false);
if special { fail!("number has a special value, \
try to_str_radix_special() if those are expected") }
r
}
}
/// Convert a string in base 16 to a float.
/// Accepts an optional binary exponent.
///
/// This function accepts strings such as
///
/// * 'a4.fe'
/// * '+a4.fe', equivalent to 'a4.fe'
/// * '-a4.fe'
/// * '2b.aP128', or equivalently, '2b.ap128'
/// * '2b.aP-128'
/// * '.' (understood as 0)
/// * 'c.'
/// * '.c', or, equivalently, '0.c'
/// * '+inf', 'inf', '-inf', 'NaN'
///
/// Leading and trailing whitespace represent an error.
///
/// # Arguments
///
/// * num - A string
///
/// # Return value
///
/// `None` if the string did not represent a valid number. Otherwise,
/// `Some(n)` where `n` is the floating-point number represented by `[num]`.
#[inline]
pub fn from_str_hex(num: &str) -> Option<f32> {
strconv::from_str_common(num, 16u, true, true, true,
strconv::ExpBin, false, false)
}
impl FromStr for f32 {
/// Convert a string in base 10 to a float.
/// Accepts an optional decimal exponent.
///
/// This function accepts strings such as
///
/// * '3.14'
/// * '+3.14', equivalent to '3.14'
/// * '-3.14'
/// * '2.5E10', or equivalently, '2.5e10'
/// * '2.5E-10'
/// * '.' (understood as 0)
/// * '5.'
/// * '.5', or, equivalently, '0.5'
/// * '+inf', 'inf', '-inf', 'NaN'
///
/// Leading and trailing whitespace represent an error.
///
/// # Arguments
///
/// * num - A string
///
/// # Return value
///
/// `None` if the string did not represent a valid number. Otherwise,
/// `Some(n)` where `n` is the floating-point number represented by `num`.
#[inline]
fn from_str(val: &str) -> Option<f32> {
strconv::from_str_common(val, 10u, true, true, true,
strconv::ExpDec, false, false)
}
}
impl num::FromStrRadix for f32 {
/// Convert a string in a given base to a float.
///
/// Due to possible conflicts, this function does **not** accept
/// the special values `inf`, `-inf`, `+inf` and `NaN`, **nor**
/// does it recognize exponents of any kind.
///
/// Leading and trailing whitespace represent an error.
///
/// # Arguments
///
/// * num - A string
/// * radix - The base to use. Must lie in the range [2 .. 36]
///
/// # Return value
///
/// `None` if the string did not represent a valid number. Otherwise,
/// `Some(n)` where `n` is the floating-point number represented by `num`.
#[inline]
fn from_str_radix(val: &str, rdx: uint) -> Option<f32> {
strconv::from_str_common(val, rdx, true, true, false,
strconv::ExpNone, false, false)
}
}
#[cfg(test)]
mod tests {
use f32::*;
use num::*;
use num;
#[test]
fn test_min_nan() {
assert_eq!(NAN.min(2.0), 2.0);
assert_eq!(2.0f32.min(NAN), 2.0);
}
#[test]
fn test_max_nan() {
assert_eq!(NAN.max(2.0), 2.0);
assert_eq!(2.0f32.max(NAN), 2.0);
}
#[test]
fn test_num() {
num::test_num(10f32, 2f32);
}
#[test]
fn test_floor() {
assert_approx_eq!(1.0f32.floor(), 1.0f32);
assert_approx_eq!(1.3f32.floor(), 1.0f32);
assert_approx_eq!(1.5f32.floor(), 1.0f32);
assert_approx_eq!(1.7f32.floor(), 1.0f32);
assert_approx_eq!(0.0f32.floor(), 0.0f32);
assert_approx_eq!((-0.0f32).floor(), -0.0f32);
assert_approx_eq!((-1.0f32).floor(), -1.0f32);
assert_approx_eq!((-1.3f32).floor(), -2.0f32);
assert_approx_eq!((-1.5f32).floor(), -2.0f32);
assert_approx_eq!((-1.7f32).floor(), -2.0f32);
}
#[test]
fn test_ceil() {
assert_approx_eq!(1.0f32.ceil(), 1.0f32);
assert_approx_eq!(1.3f32.ceil(), 2.0f32);
assert_approx_eq!(1.5f32.ceil(), 2.0f32);
assert_approx_eq!(1.7f32.ceil(), 2.0f32);
assert_approx_eq!(0.0f32.ceil(), 0.0f32);
assert_approx_eq!((-0.0f32).ceil(), -0.0f32);
assert_approx_eq!((-1.0f32).ceil(), -1.0f32);
assert_approx_eq!((-1.3f32).ceil(), -1.0f32);
assert_approx_eq!((-1.5f32).ceil(), -1.0f32);
assert_approx_eq!((-1.7f32).ceil(), -1.0f32);
}
#[test]
fn test_round() {
assert_approx_eq!(1.0f32.round(), 1.0f32);
assert_approx_eq!(1.3f32.round(), 1.0f32);
assert_approx_eq!(1.5f32.round(), 2.0f32);
assert_approx_eq!(1.7f32.round(), 2.0f32);
assert_approx_eq!(0.0f32.round(), 0.0f32);
assert_approx_eq!((-0.0f32).round(), -0.0f32);
assert_approx_eq!((-1.0f32).round(), -1.0f32);
assert_approx_eq!((-1.3f32).round(), -1.0f32);
assert_approx_eq!((-1.5f32).round(), -2.0f32);
assert_approx_eq!((-1.7f32).round(), -2.0f32);
}
#[test]
fn test_trunc() {
assert_approx_eq!(1.0f32.trunc(), 1.0f32);
assert_approx_eq!(1.3f32.trunc(), 1.0f32);
assert_approx_eq!(1.5f32.trunc(), 1.0f32);
assert_approx_eq!(1.7f32.trunc(), 1.0f32);
assert_approx_eq!(0.0f32.trunc(), 0.0f32);
assert_approx_eq!((-0.0f32).trunc(), -0.0f32);
assert_approx_eq!((-1.0f32).trunc(), -1.0f32);
assert_approx_eq!((-1.3f32).trunc(), -1.0f32);
assert_approx_eq!((-1.5f32).trunc(), -1.0f32);
assert_approx_eq!((-1.7f32).trunc(), -1.0f32);
}
#[test]
fn test_fract() {
assert_approx_eq!(1.0f32.fract(), 0.0f32);
assert_approx_eq!(1.3f32.fract(), 0.3f32);
assert_approx_eq!(1.5f32.fract(), 0.5f32);
assert_approx_eq!(1.7f32.fract(), 0.7f32);
assert_approx_eq!(0.0f32.fract(), 0.0f32);
assert_approx_eq!((-0.0f32).fract(), -0.0f32);
assert_approx_eq!((-1.0f32).fract(), -0.0f32);
assert_approx_eq!((-1.3f32).fract(), -0.3f32);
assert_approx_eq!((-1.5f32).fract(), -0.5f32);
assert_approx_eq!((-1.7f32).fract(), -0.7f32);
}
#[test]
fn test_asinh() {
assert_eq!(0.0f32.asinh(), 0.0f32);
assert_eq!((-0.0f32).asinh(), -0.0f32);
let inf: f32 = Float::infinity();
let neg_inf: f32 = Float::neg_infinity();
let nan: f32 = Float::nan();
assert_eq!(inf.asinh(), inf);
assert_eq!(neg_inf.asinh(), neg_inf);
assert!(nan.asinh().is_nan());
assert_approx_eq!(2.0f32.asinh(), 1.443635475178810342493276740273105f32);
assert_approx_eq!((-2.0f32).asinh(), -1.443635475178810342493276740273105f32);
}
#[test]
fn test_acosh() {
assert_eq!(1.0f32.acosh(), 0.0f32);
assert!(0.999f32.acosh().is_nan());
let inf: f32 = Float::infinity();
let neg_inf: f32 = Float::neg_infinity();
let nan: f32 = Float::nan();
assert_eq!(inf.acosh(), inf);
assert!(neg_inf.acosh().is_nan());
assert!(nan.acosh().is_nan());
assert_approx_eq!(2.0f32.acosh(), 1.31695789692481670862504634730796844f32);
assert_approx_eq!(3.0f32.acosh(), 1.76274717403908605046521864995958461f32);
}
#[test]
fn test_atanh() {
assert_eq!(0.0f32.atanh(), 0.0f32);
assert_eq!((-0.0f32).atanh(), -0.0f32);
let inf32: f32 = Float::infinity();
let neg_inf32: f32 = Float::neg_infinity();
assert_eq!(1.0f32.atanh(), inf32);
assert_eq!((-1.0f32).atanh(), neg_inf32);
assert!(2f64.atanh().atanh().is_nan());
assert!((-2f64).atanh().atanh().is_nan());
let inf64: f32 = Float::infinity();
let neg_inf64: f32 = Float::neg_infinity();
let nan32: f32 = Float::nan();
assert!(inf64.atanh().is_nan());
assert!(neg_inf64.atanh().is_nan());
assert!(nan32.atanh().is_nan());
assert_approx_eq!(0.5f32.atanh(), 0.54930614433405484569762261846126285f32);
assert_approx_eq!((-0.5f32).atanh(), -0.54930614433405484569762261846126285f32);
}
#[test]
fn test_real_consts() {
let pi: f32 = Float::pi();
let two_pi: f32 = Float::two_pi();
let frac_pi_2: f32 = Float::frac_pi_2();
let frac_pi_3: f32 = Float::frac_pi_3();
let frac_pi_4: f32 = Float::frac_pi_4();
let frac_pi_6: f32 = Float::frac_pi_6();
let frac_pi_8: f32 = Float::frac_pi_8();
let frac_1_pi: f32 = Float::frac_1_pi();
let frac_2_pi: f32 = Float::frac_2_pi();
let frac_2_sqrtpi: f32 = Float::frac_2_sqrtpi();
let sqrt2: f32 = Float::sqrt2();
let frac_1_sqrt2: f32 = Float::frac_1_sqrt2();
let e: f32 = Float::e();
let log2_e: f32 = Float::log2_e();
let log10_e: f32 = Float::log10_e();
let ln_2: f32 = Float::ln_2();
let ln_10: f32 = Float::ln_10();
assert_approx_eq!(two_pi, 2f32 * pi);
assert_approx_eq!(frac_pi_2, pi / 2f32);
assert_approx_eq!(frac_pi_3, pi / 3f32);
assert_approx_eq!(frac_pi_4, pi / 4f32);
assert_approx_eq!(frac_pi_6, pi / 6f32);
assert_approx_eq!(frac_pi_8, pi / 8f32);
assert_approx_eq!(frac_1_pi, 1f32 / pi);
assert_approx_eq!(frac_2_pi, 2f32 / pi);
assert_approx_eq!(frac_2_sqrtpi, 2f32 / pi.sqrt());
assert_approx_eq!(sqrt2, 2f32.sqrt());
assert_approx_eq!(frac_1_sqrt2, 1f32 / 2f32.sqrt());
assert_approx_eq!(log2_e, e.log2());
assert_approx_eq!(log10_e, e.log10());
assert_approx_eq!(ln_2, 2f32.ln());
assert_approx_eq!(ln_10, 10f32.ln());
}
#[test]
pub fn test_abs() {
assert_eq!(INFINITY.abs(), INFINITY);
assert_eq!(1f32.abs(), 1f32);
assert_eq!(0f32.abs(), 0f32);
assert_eq!((-0f32).abs(), 0f32);
assert_eq!((-1f32).abs(), 1f32);
assert_eq!(NEG_INFINITY.abs(), INFINITY);
assert_eq!((1f32/NEG_INFINITY).abs(), 0f32);
assert!(NAN.abs().is_nan());
}
#[test]
fn test_abs_sub() {
assert_eq!((-1f32).abs_sub(&1f32), 0f32);
assert_eq!(1f32.abs_sub(&1f32), 0f32);
assert_eq!(1f32.abs_sub(&0f32), 1f32);
assert_eq!(1f32.abs_sub(&-1f32), 2f32);
assert_eq!(NEG_INFINITY.abs_sub(&0f32), 0f32);
assert_eq!(INFINITY.abs_sub(&1f32), INFINITY);
assert_eq!(0f32.abs_sub(&NEG_INFINITY), INFINITY);
assert_eq!(0f32.abs_sub(&INFINITY), 0f32);
}
#[test]
fn test_abs_sub_nowin() {
assert!(NAN.abs_sub(&-1f32).is_nan());
assert!(1f32.abs_sub(&NAN).is_nan());
}
#[test]
fn test_signum() {
assert_eq!(INFINITY.signum(), 1f32);
assert_eq!(1f32.signum(), 1f32);
assert_eq!(0f32.signum(), 1f32);
assert_eq!((-0f32).signum(), -1f32);
assert_eq!((-1f32).signum(), -1f32);
assert_eq!(NEG_INFINITY.signum(), -1f32);
assert_eq!((1f32/NEG_INFINITY).signum(), -1f32);
assert!(NAN.signum().is_nan());
}
#[test]
fn test_is_positive() {
assert!(INFINITY.is_positive());
assert!(1f32.is_positive());
assert!(0f32.is_positive());
assert!(!(-0f32).is_positive());
assert!(!(-1f32).is_positive());
assert!(!NEG_INFINITY.is_positive());
assert!(!(1f32/NEG_INFINITY).is_positive());
assert!(!NAN.is_positive());
}
#[test]
fn test_is_negative() {
assert!(!INFINITY.is_negative());
assert!(!1f32.is_negative());
assert!(!0f32.is_negative());
assert!((-0f32).is_negative());
assert!((-1f32).is_negative());
assert!(NEG_INFINITY.is_negative());
assert!((1f32/NEG_INFINITY).is_negative());
assert!(!NAN.is_negative());
}
#[test]
fn test_is_normal() {
let nan: f32 = Float::nan();
let inf: f32 = Float::infinity();
let neg_inf: f32 = Float::neg_infinity();
let zero: f32 = Zero::zero();
let neg_zero: f32 = Float::neg_zero();
assert!(!nan.is_normal());
assert!(!inf.is_normal());
assert!(!neg_inf.is_normal());
assert!(!zero.is_normal());
assert!(!neg_zero.is_normal());
assert!(1f32.is_normal());
assert!(1e-37f32.is_normal());
assert!(!1e-38f32.is_normal());
}
#[test]
fn test_classify() {
let nan: f32 = Float::nan();
let inf: f32 = Float::infinity();
let neg_inf: f32 = Float::neg_infinity();
let zero: f32 = Zero::zero();
let neg_zero: f32 = Float::neg_zero();
assert_eq!(nan.classify(), FPNaN);
assert_eq!(inf.classify(), FPInfinite);
assert_eq!(neg_inf.classify(), FPInfinite);
assert_eq!(zero.classify(), FPZero);
assert_eq!(neg_zero.classify(), FPZero);
assert_eq!(1f32.classify(), FPNormal);
assert_eq!(1e-37f32.classify(), FPNormal);
assert_eq!(1e-38f32.classify(), FPSubnormal);
}
#[test]
fn test_ldexp() {
// We have to use from_str until base-2 exponents
// are supported in floating-point literals
let f1: f32 = from_str_hex("1p-123").unwrap();
let f2: f32 = from_str_hex("1p-111").unwrap();
assert_eq!(FloatMath::ldexp(1f32, -123), f1);
assert_eq!(FloatMath::ldexp(1f32, -111), f2);
assert_eq!(FloatMath::ldexp(0f32, -123), 0f32);
assert_eq!(FloatMath::ldexp(-0f32, -123), -0f32);
let inf: f32 = Float::infinity();
let neg_inf: f32 = Float::neg_infinity();
let nan: f32 = Float::nan();
assert_eq!(FloatMath::ldexp(inf, -123), inf);
assert_eq!(FloatMath::ldexp(neg_inf, -123), neg_inf);
assert!(FloatMath::ldexp(nan, -123).is_nan());
}
#[test]
fn test_frexp() {
// We have to use from_str until base-2 exponents
// are supported in floating-point literals
let f1: f32 = from_str_hex("1p-123").unwrap();
let f2: f32 = from_str_hex("1p-111").unwrap();
let (x1, exp1) = f1.frexp();
let (x2, exp2) = f2.frexp();
assert_eq!((x1, exp1), (0.5f32, -122));
assert_eq!((x2, exp2), (0.5f32, -110));
assert_eq!(FloatMath::ldexp(x1, exp1), f1);
assert_eq!(FloatMath::ldexp(x2, exp2), f2);
assert_eq!(0f32.frexp(), (0f32, 0));
assert_eq!((-0f32).frexp(), (-0f32, 0));
}
#[test] #[ignore(cfg(windows))] // FIXME #8755
fn test_frexp_nowin() {
let inf: f32 = Float::infinity();
let neg_inf: f32 = Float::neg_infinity();
let nan: f32 = Float::nan();
assert_eq!(match inf.frexp() { (x, _) => x }, inf)
assert_eq!(match neg_inf.frexp() { (x, _) => x }, neg_inf)
assert!(match nan.frexp() { (x, _) => x.is_nan() })
}
#[test]
fn test_integer_decode() {
assert_eq!(3.14159265359f32.integer_decode(), (13176795u64, -22i16, 1i8));
assert_eq!((-8573.5918555f32).integer_decode(), (8779358u64, -10i16, -1i8));
assert_eq!(2f32.powf(100.0).integer_decode(), (8388608u64, 77i16, 1i8));
assert_eq!(0f32.integer_decode(), (0u64, -150i16, 1i8));
assert_eq!((-0f32).integer_decode(), (0u64, -150i16, -1i8));
assert_eq!(INFINITY.integer_decode(), (8388608u64, 105i16, 1i8));
assert_eq!(NEG_INFINITY.integer_decode(), (8388608u64, 105i16, -1i8));
assert_eq!(NAN.integer_decode(), (12582912u64, 105i16, 1i8));
}
}
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