1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206

#![allow(deprecated, clippy::missing_const_for_fn)]

use core::ops::{Div, DivAssign, Mul, MulAssign, Neg, Not};
#[cfg(feature = "serde")]
use standback::convert::TryInto;
use Sign::{Negative, Positive, Zero};

/// Contains the sign of a value: positive, negative, or zero.
///
/// For ease of use, `Sign` implements [`Mul`] and [`Div`] on all signed numeric
/// types. `Sign`s can also be multiplied and divided by another `Sign`, which
/// follows the same rules as real numbers.
#[repr(i8)]
#[cfg_attr(feature = "serde", derive(serde::Serialize))]
#[cfg_attr(feature = "serde", serde(into = "crate::serde::Sign"))]
#[deprecated(
    since = "0.2.7",
    note = "The only use for this (obtaining the sign of a `Duration`) can be replaced with \
            `Duration::is_{positive|negative|zero}`"
)]
#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
pub enum Sign {
    /// A positive value.
    Positive = 1,

    /// A negative value.
    Negative = -1,

    /// A value that is exactly zero.
    Zero = 0,
}

#[cfg(feature = "serde")]
impl<'a> serde::Deserialize<'a> for Sign {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: serde::Deserializer<'a>,
    {
        crate::serde::Sign::deserialize(deserializer)?
            .try_into()
            .map_err(serde::de::Error::custom)
    }
}
impl Default for Sign {
    /// `Sign` defaults to `Zero`.
    ///
    /// ```rust
    /// # #![allow(deprecated)]
    /// # use time::Sign;
    /// assert_eq!(Sign::default(), Sign::Zero);
    /// ```
    fn default() -> Self {
        Zero
    }
}

macro_rules! sign_mul {
    ($($type:ty),+ $(,)?) => {
        $(
            impl Mul<$type> for Sign {
                type Output = $type;

                #[allow(trivial_numeric_casts)]
                fn mul(self, rhs: $type) -> Self::Output {
                    (self as i8) as $type * rhs
                }
            }

            impl Mul<Sign> for $type {
                type Output = Self;

                fn mul(self, rhs: Sign) -> Self::Output {
                    rhs * self
                }
            }

            impl MulAssign<Sign> for $type {
                #[allow(trivial_numeric_casts)]
                fn mul_assign(&mut self, rhs: Sign) {
                    *self *= rhs as i8 as $type;
                }
            }

            impl Div<Sign> for $type {
                type Output = Self;

                fn div(self, rhs: Sign) -> Self::Output {
                    self * rhs
                }
            }

            impl DivAssign<Sign> for $type {
                fn div_assign(&mut self, rhs: Sign) {
                    *self *= rhs
                }
            }
        )*
    };
}
sign_mul![i8, i16, i32, i64, i128, f32, f64];

impl Mul<Sign> for Sign {
    type Output = Self;

    fn mul(self, rhs: Self) -> Self::Output {
        match (self, rhs) {
            (Zero, _) | (_, Zero) => Zero,
            (Positive, Positive) | (Negative, Negative) => Positive,
            (Positive, Negative) | (Negative, Positive) => Negative,
        }
    }
}

impl MulAssign<Sign> for Sign {
    fn mul_assign(&mut self, rhs: Self) {
        *self = *self * rhs;
    }
}

impl Div<Sign> for Sign {
    type Output = Self;

    fn div(self, rhs: Self) -> Self::Output {
        self * rhs
    }
}

impl DivAssign<Sign> for Sign {
    fn div_assign(&mut self, rhs: Self) {
        *self *= rhs
    }
}

impl Neg for Sign {
    type Output = Self;

    fn neg(self) -> Self::Output {
        self.negate()
    }
}

impl Not for Sign {
    type Output = Self;

    fn not(self) -> Self::Output {
        self.negate()
    }
}

impl Sign {
    /// Return the opposite of the current sign.
    ///
    /// ```rust
    /// # #![allow(deprecated)]
    /// # use time::Sign;
    /// assert_eq!(Sign::Positive.negate(), Sign::Negative);
    /// assert_eq!(Sign::Negative.negate(), Sign::Positive);
    /// assert_eq!(Sign::Zero.negate(), Sign::Zero);
    /// ```
    pub fn negate(self) -> Self {
        match self {
            Positive => Negative,
            Negative => Positive,
            Zero => Zero,
        }
    }

    /// Is the sign positive?
    ///
    /// ```rust
    /// # #![allow(deprecated)]
    /// # use time::Sign;
    /// assert!(Sign::Positive.is_positive());
    /// assert!(!Sign::Negative.is_positive());
    /// assert!(!Sign::Zero.is_positive());
    /// ```
    pub const fn is_positive(self) -> bool {
        self as u8 == Positive as u8
    }

    /// Is the sign negative?
    ///
    /// ```rust
    /// # #![allow(deprecated)]
    /// # use time::Sign;
    /// assert!(!Sign::Positive.is_negative());
    /// assert!(Sign::Negative.is_negative());
    /// assert!(!Sign::Zero.is_negative());
    /// ```
    pub const fn is_negative(self) -> bool {
        self as u8 == Negative as u8
    }

    /// Is the value exactly zero?
    ///
    /// ```rust
    /// # #![allow(deprecated)]
    /// # use time::Sign;
    /// assert!(!Sign::Positive.is_zero());
    /// assert!(!Sign::Negative.is_zero());
    /// assert!(Sign::Zero.is_zero());
    /// ```
    pub const fn is_zero(self) -> bool {
        self as u8 == Zero as u8
    }
}