/rust/registry/src/index.crates.io-6f17d22bba15001f/num-traits-0.2.19/src/sign.rs

Source (jump to first uncovered line)
use core::num::Wrapping;
use core::ops::Neg;

use crate::float::FloatCore;
use crate::Num;

/// Useful functions for signed numbers (i.e. numbers that can be negative).
pub trait Signed: Sized + Num + Neg<Output = Self> {
    /// Computes the absolute value.
    ///
    /// For `f32` and `f64`, `NaN` will be returned if the number is `NaN`.
    ///
    /// For signed integers, `::MIN` will be returned if the number is `::MIN`.
    fn abs(&self) -> Self;

    /// The positive difference of two numbers.
    ///
    /// Returns `zero` if the number is less than or equal to `other`, otherwise the difference
    /// between `self` and `other` is returned.
    fn abs_sub(&self, other: &Self) -> Self;

    /// Returns the sign of the number.
    ///
    /// For `f32` and `f64`:
    ///
    /// * `1.0` if the number is positive, `+0.0` or `INFINITY`
    /// * `-1.0` if the number is negative, `-0.0` or `NEG_INFINITY`
    /// * `NaN` if the number is `NaN`
    ///
    /// For signed integers:
    ///
    /// * `0` if the number is zero
    /// * `1` if the number is positive
    /// * `-1` if the number is negative
    fn signum(&self) -> Self;

    /// Returns true if the number is positive and false if the number is zero or negative.
    fn is_positive(&self) -> bool;

    /// Returns true if the number is negative and false if the number is zero or positive.
    fn is_negative(&self) -> bool;
}

macro_rules! signed_impl {
    ($($t:ty)*) => ($(
        impl Signed for $t {
            #[inline]
            fn abs(&self) -> $t {
                if self.is_negative() { -*self } else { *self }
            }

            #[inline]
            fn abs_sub(&self, other: &$t) -> $t {
                if *self <= *other { 0 } else { *self - *other }
            }

            #[inline]
            fn signum(&self) -> $t {
                match *self {
                    n if n > 0 => 1,
                    0 => 0,
                    _ => -1,
                }
            }

            #[inline]
            fn is_positive(&self) -> bool { *self > 0 }

            #[inline]
            fn is_negative(&self) -> bool { *self < 0 }
        }
    )*)
}

signed_impl!(isize i8 i16 i32 i64 i128);

impl<T: Signed> Signed for Wrapping<T>
where
    Wrapping<T>: Num + Neg<Output = Wrapping<T>>,
{
    #[inline]
    fn abs(&self) -> Self {
        Wrapping(self.0.abs())
    }

    #[inline]
    fn abs_sub(&self, other: &Self) -> Self {
        Wrapping(self.0.abs_sub(&other.0))
    }

    #[inline]
    fn signum(&self) -> Self {
        Wrapping(self.0.signum())
    }

    #[inline]
    fn is_positive(&self) -> bool {
        self.0.is_positive()
    }

    #[inline]
    fn is_negative(&self) -> bool {
        self.0.is_negative()
    }
}

macro_rules! signed_float_impl {
    ($t:ty) => {
        impl Signed for $t {
            /// Computes the absolute value. Returns `NAN` if the number is `NAN`.
            #[inline]
            fn abs(&self) -> $t {
                FloatCore::abs(*self)
            }

            /// The positive difference of two numbers. Returns `0.0` if the number is
            /// less than or equal to `other`, otherwise the difference between`self`
            /// and `other` is returned.
            #[inline]
            fn abs_sub(&self, other: &$t) -> $t {
                if *self <= *other {
                    0.
                } else {
                    *self - *other
                }
            }

            /// # Returns
            ///
            /// - `1.0` if the number is positive, `+0.0` or `INFINITY`
            /// - `-1.0` if the number is negative, `-0.0` or `NEG_INFINITY`
            /// - `NAN` if the number is NaN
            #[inline]
            fn signum(&self) -> $t {
                FloatCore::signum(*self)
            }

            /// Returns `true` if the number is positive, including `+0.0` and `INFINITY`
            #[inline]
            fn is_positive(&self) -> bool {
                FloatCore::is_sign_positive(*self)
            }

            /// Returns `true` if the number is negative, including `-0.0` and `NEG_INFINITY`
            #[inline]
            fn is_negative(&self) -> bool {
                FloatCore::is_sign_negative(*self)
            }
        }
    };
}

signed_float_impl!(f32);
signed_float_impl!(f64);

/// Computes the absolute value.
///
/// For `f32` and `f64`, `NaN` will be returned if the number is `NaN`
///
/// For signed integers, `::MIN` will be returned if the number is `::MIN`.
#[inline(always)]
pub fn abs<T: Signed>(value: T) -> T {
    value.abs()
}

/// The positive difference of two numbers.
///
/// Returns zero if `x` is less than or equal to `y`, otherwise the difference
/// between `x` and `y` is returned.
#[inline(always)]
pub fn abs_sub<T: Signed>(x: T, y: T) -> T {
    x.abs_sub(&y)
}

/// Returns the sign of the number.
///
/// For `f32` and `f64`:
///
/// * `1.0` if the number is positive, `+0.0` or `INFINITY`
/// * `-1.0` if the number is negative, `-0.0` or `NEG_INFINITY`
/// * `NaN` if the number is `NaN`
///
/// For signed integers:
///
/// * `0` if the number is zero
/// * `1` if the number is positive
/// * `-1` if the number is negative
#[inline(always)]
pub fn signum<T: Signed>(value: T) -> T {
    value.signum()
}

/// A trait for values which cannot be negative
pub trait Unsigned: Num {}

macro_rules! empty_trait_impl {
    ($name:ident for $($t:ty)*) => ($(
        impl $name for $t {}
    )*)
}

empty_trait_impl!(Unsigned for usize u8 u16 u32 u64 u128);

impl<T: Unsigned> Unsigned for Wrapping<T> where Wrapping<T>: Num {}

#[test]
fn unsigned_wrapping_is_unsigned() {
    fn require_unsigned<T: Unsigned>(_: &T) {}
    require_unsigned(&Wrapping(42_u32));
}

#[test]
fn signed_wrapping_is_signed() {
    fn require_signed<T: Signed>(_: &T) {}
    require_signed(&Wrapping(-42));
}

Coverage Report

Created: 2025-09-05 06:34

Line	Count	Source (jump to first uncovered line)
1		use core::num::Wrapping;
2		use core::ops::Neg;
3
4		use crate::float::FloatCore;
5		use crate::Num;
6
7		/// Useful functions for signed numbers (i.e. numbers that can be negative).
8		pub trait Signed: Sized + Num + Neg<Output = Self> {
9		/// Computes the absolute value.
10		///
11		/// For `f32` and `f64`, `NaN` will be returned if the number is `NaN`.
12		///
13		/// For signed integers, `::MIN` will be returned if the number is `::MIN`.
14		fn abs(&self) -> Self;
15
16		/// The positive difference of two numbers.
17		///
18		/// Returns `zero` if the number is less than or equal to `other`, otherwise the difference
19		/// between `self` and `other` is returned.
20		fn abs_sub(&self, other: &Self) -> Self;
21
22		/// Returns the sign of the number.
23		///
24		/// For `f32` and `f64`:
25		///
26		/// * `1.0` if the number is positive, `+0.0` or `INFINITY`
27		/// * `-1.0` if the number is negative, `-0.0` or `NEG_INFINITY`
28		/// * `NaN` if the number is `NaN`
29		///
30		/// For signed integers:
31		///
32		/// * `0` if the number is zero
33		/// * `1` if the number is positive
34		/// * `-1` if the number is negative
35		fn signum(&self) -> Self;
36
37		/// Returns true if the number is positive and false if the number is zero or negative.
38		fn is_positive(&self) -> bool;
39
40		/// Returns true if the number is negative and false if the number is zero or positive.
41		fn is_negative(&self) -> bool;
42		}
43
44		macro_rules! signed_impl {
45		($($t:ty)*) => ($(
46		impl Signed for $t {
47		#[inline]
48	0	fn abs(&self) -> $t {
49	0	if self.is_negative() { -self } else { self }
50	0	} Unexecuted instantiation: <isize as num_traits::sign::Signed>::abs Unexecuted instantiation: <i8 as num_traits::sign::Signed>::abs Unexecuted instantiation: <i16 as num_traits::sign::Signed>::abs Unexecuted instantiation: <i32 as num_traits::sign::Signed>::abs Unexecuted instantiation: <i64 as num_traits::sign::Signed>::abs Unexecuted instantiation: <i128 as num_traits::sign::Signed>::abs
51
52		#[inline]
53	0	fn abs_sub(&self, other: &$t) -> $t {
54	0	if self <= other { 0 } else { self - other }
55	0	} Unexecuted instantiation: <isize as num_traits::sign::Signed>::abs_sub Unexecuted instantiation: <i8 as num_traits::sign::Signed>::abs_sub Unexecuted instantiation: <i16 as num_traits::sign::Signed>::abs_sub Unexecuted instantiation: <i32 as num_traits::sign::Signed>::abs_sub Unexecuted instantiation: <i64 as num_traits::sign::Signed>::abs_sub Unexecuted instantiation: <i128 as num_traits::sign::Signed>::abs_sub
56
57		#[inline]
58	0	fn signum(&self) -> $t {
59	0	match *self {
60	0	n if n > 0 => 1,
61	0	0 => 0,
62	0	_ => -1,
63		}
64	0	} Unexecuted instantiation: <isize as num_traits::sign::Signed>::signum Unexecuted instantiation: <i8 as num_traits::sign::Signed>::signum Unexecuted instantiation: <i16 as num_traits::sign::Signed>::signum Unexecuted instantiation: <i32 as num_traits::sign::Signed>::signum Unexecuted instantiation: <i64 as num_traits::sign::Signed>::signum Unexecuted instantiation: <i128 as num_traits::sign::Signed>::signum
65
66		#[inline]
67	0	fn is_positive(&self) -> bool { *self > 0 } Unexecuted instantiation: <isize as num_traits::sign::Signed>::is_positive Unexecuted instantiation: <i8 as num_traits::sign::Signed>::is_positive Unexecuted instantiation: <i16 as num_traits::sign::Signed>::is_positive Unexecuted instantiation: <i32 as num_traits::sign::Signed>::is_positive Unexecuted instantiation: <i64 as num_traits::sign::Signed>::is_positive Unexecuted instantiation: <i128 as num_traits::sign::Signed>::is_positive
68
69		#[inline]
70	0	fn is_negative(&self) -> bool { *self < 0 } Unexecuted instantiation: <isize as num_traits::sign::Signed>::is_negative Unexecuted instantiation: <i8 as num_traits::sign::Signed>::is_negative Unexecuted instantiation: <i16 as num_traits::sign::Signed>::is_negative Unexecuted instantiation: <i32 as num_traits::sign::Signed>::is_negative Unexecuted instantiation: <i64 as num_traits::sign::Signed>::is_negative Unexecuted instantiation: <i128 as num_traits::sign::Signed>::is_negative
71		}
72		)*)
73		}
74
75		signed_impl!(isize i8 i16 i32 i64 i128);
76
77		impl<T: Signed> Signed for Wrapping<T>
78		where
79		Wrapping<T>: Num + Neg<Output = Wrapping<T>>,
80		{
81		#[inline]
82	0	fn abs(&self) -> Self {
83	0	Wrapping(self.0.abs())
84	0	}
85
86		#[inline]
87	0	fn abs_sub(&self, other: &Self) -> Self {
88	0	Wrapping(self.0.abs_sub(&other.0))
89	0	}
90
91		#[inline]
92	0	fn signum(&self) -> Self {
93	0	Wrapping(self.0.signum())
94	0	}
95
96		#[inline]
97	0	fn is_positive(&self) -> bool {
98	0	self.0.is_positive()
99	0	}
100
101		#[inline]
102	0	fn is_negative(&self) -> bool {
103	0	self.0.is_negative()
104	0	}
105		}
106
107		macro_rules! signed_float_impl {
108		($t:ty) => {
109		impl Signed for $t {
110		/// Computes the absolute value. Returns `NAN` if the number is `NAN`.
111		#[inline]
112	0	fn abs(&self) -> $t {
113	0	FloatCore::abs(*self)
114	0	} Unexecuted instantiation: <f32 as num_traits::sign::Signed>::abs Unexecuted instantiation: <f64 as num_traits::sign::Signed>::abs
115
116		/// The positive difference of two numbers. Returns `0.0` if the number is
117		/// less than or equal to `other`, otherwise the difference between`self`
118		/// and `other` is returned.
119		#[inline]
120	0	fn abs_sub(&self, other: &$t) -> $t {
121	0	if self <= other {
122	0	0.
123		} else {
124	0	self - other
125		}
126	0	} Unexecuted instantiation: <f32 as num_traits::sign::Signed>::abs_sub Unexecuted instantiation: <f64 as num_traits::sign::Signed>::abs_sub
127
128		/// # Returns
129		///
130		/// - `1.0` if the number is positive, `+0.0` or `INFINITY`
131		/// - `-1.0` if the number is negative, `-0.0` or `NEG_INFINITY`
132		/// - `NAN` if the number is NaN
133		#[inline]
134	0	fn signum(&self) -> $t {
135	0	FloatCore::signum(*self)
136	0	} Unexecuted instantiation: <f32 as num_traits::sign::Signed>::signum Unexecuted instantiation: <f64 as num_traits::sign::Signed>::signum
137
138		/// Returns `true` if the number is positive, including `+0.0` and `INFINITY`
139		#[inline]
140	0	fn is_positive(&self) -> bool {
141	0	FloatCore::is_sign_positive(*self)
142	0	} Unexecuted instantiation: <f32 as num_traits::sign::Signed>::is_positive Unexecuted instantiation: <f64 as num_traits::sign::Signed>::is_positive
143
144		/// Returns `true` if the number is negative, including `-0.0` and `NEG_INFINITY`
145		#[inline]
146	0	fn is_negative(&self) -> bool {
147	0	FloatCore::is_sign_negative(*self)
148	0	} Unexecuted instantiation: <f32 as num_traits::sign::Signed>::is_negative Unexecuted instantiation: <f64 as num_traits::sign::Signed>::is_negative
149		}
150		};
151		}
152
153		signed_float_impl!(f32);
154		signed_float_impl!(f64);
155
156		/// Computes the absolute value.
157		///
158		/// For `f32` and `f64`, `NaN` will be returned if the number is `NaN`
159		///
160		/// For signed integers, `::MIN` will be returned if the number is `::MIN`.
161		#[inline(always)]
162	0	pub fn abs<T: Signed>(value: T) -> T {
163	0	value.abs()
164	0	}
165
166		/// The positive difference of two numbers.
167		///
168		/// Returns zero if `x` is less than or equal to `y`, otherwise the difference
169		/// between `x` and `y` is returned.
170		#[inline(always)]
171	0	pub fn abs_sub<T: Signed>(x: T, y: T) -> T {
172	0	x.abs_sub(&y)
173	0	}
174
175		/// Returns the sign of the number.
176		///
177		/// For `f32` and `f64`:
178		///
179		/// * `1.0` if the number is positive, `+0.0` or `INFINITY`
180		/// * `-1.0` if the number is negative, `-0.0` or `NEG_INFINITY`
181		/// * `NaN` if the number is `NaN`
182		///
183		/// For signed integers:
184		///
185		/// * `0` if the number is zero
186		/// * `1` if the number is positive
187		/// * `-1` if the number is negative
188		#[inline(always)]
189	0	pub fn signum<T: Signed>(value: T) -> T {
190	0	value.signum()
191	0	}
192
193		/// A trait for values which cannot be negative
194		pub trait Unsigned: Num {}
195
196		macro_rules! empty_trait_impl {
197		($name:ident for $($t:ty)*) => ($(
198		impl $name for $t {}
199		)*)
200		}
201
202		empty_trait_impl!(Unsigned for usize u8 u16 u32 u64 u128);
203
204		impl<T: Unsigned> Unsigned for Wrapping<T> where Wrapping<T>: Num {}
205
206		#[test]
207		fn unsigned_wrapping_is_unsigned() {
208		fn require_unsigned<T: Unsigned>(_: &T) {}
209		require_unsigned(&Wrapping(42_u32));
210		}
211
212		#[test]
213		fn signed_wrapping_is_signed() {
214		fn require_signed<T: Signed>(_: &T) {}
215		require_signed(&Wrapping(-42));
216		}