Trait Sub

1.0.0 (const: unstable) · Source

pub trait Sub<Rhs = Self> {
    type Output;

    // Required method
    fn sub(self, rhs: Rhs) -> Self::Output;
}

Expand description

The subtraction operator -.

Note that Rhs is Self by default, but this is not mandatory. For example, std::time::SystemTime implements Sub<Duration>, which permits operations of the form SystemTime = SystemTime - Duration.

§Examples

§`Sub`tractable points

use std::ops::Sub;

#[derive(Debug, Copy, Clone, PartialEq)]
struct Point {
    x: i32,
    y: i32,
}

impl Sub for Point {
    type Output = Self;

    fn sub(self, other: Self) -> Self::Output {
        Self {
            x: self.x - other.x,
            y: self.y - other.y,
        }
    }
}

assert_eq!(Point { x: 3, y: 3 } - Point { x: 2, y: 3 },
           Point { x: 1, y: 0 });

§Implementing `Sub` with generics

Here is an example of the same Point struct implementing the Sub trait using generics.

use std::ops::Sub;

#[derive(Debug, PartialEq)]
struct Point<T> {
    x: T,
    y: T,
}

// Notice that the implementation uses the associated type `Output`.
impl<T: Sub<Output = T>> Sub for Point<T> {
    type Output = Self;

    fn sub(self, other: Self) -> Self::Output {
        Point {
            x: self.x - other.x,
            y: self.y - other.y,
        }
    }
}

assert_eq!(Point { x: 2, y: 3 } - Point { x: 1, y: 0 },
           Point { x: 1, y: 3 });

To configure the largest unit or enable rounding, use DateTime::since.

If you need a SignedDuration representing the span between two civil datetimes, then use DateTime::duration_since.

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type Output = Span

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impl Sub for Time

Computes the span of time between two times.

This will return a negative span when the time being subtracted is greater.

Since this uses the default configuration for calculating a span between two times (no rounding and largest units is hours), this will never panic or fail in any way.

To configure the largest unit or enable rounding, use Time::since.

Source §

type Output = Span

Computes the span of time between two zoned datetimes.

This will return a negative span when the zoned datetime being subtracted is greater.

Since this uses the default configuration for calculating a span between two zoned datetimes (no rounding and largest units is hours), this will never panic or fail in any way. It is guaranteed that the largest non-zero unit in the Span returned will be hours.

To configure the largest unit or enable rounding, use Zoned::since.

Using this implementation will result in consuming the Zoned value. Since it is not Copy, this will prevent further use. If this is undesirable, consider using the trait implementation for &Zoned, Zoned::since, Zoned::until or cloning the Zoned value.

UTerm - UTerm = UTerm

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type Output = UTerm

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impl Sub for Z0

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This uses checked arithmetic and panics on overflow. To handle overflow without panics, use Zoned::checked_sub.

Using this implementation will result in consuming the Zoned value. Since it is not Copy, this will prevent further use. If this is undesirable, consider using the trait implementation for &Zoned, Zoned::checked_sub or cloning the Zoned value.

UTerm - B0 = Term

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type Output = UTerm

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impl Sub<B1> for UInt<UTerm, B1>

UInt<UTerm, B1> - B1 = UTerm

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type Output = UTerm

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impl<'a> Sub for &'a Zoned

Computes the span of time between two borrowed zoned datetimes.

This will return a negative span when the zoned datetime being subtracted is greater.

Since this uses the default configuration for calculating a span between two zoned datetimes (no rounding and largest units is hours), this will never panic or fail in any way. It is guaranteed that the largest non-zero unit in the Span returned will be hours.

To configure the largest unit or enable rounding, use Zoned::since.

Using this implementation will result in consuming the Zoned value. Since it is not Copy, this will prevent further use. If this is undesirable, consider using the trait implementation for &Zoned, Zoned::checked_sub or cloning the Zoned value.

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Sub

Trait Sub Copy item path

§Examples

§Subtractable points

§Implementing Sub with generics

Required Associated Types§

type Output

Required Methods§

fn sub(self, rhs: Rhs) -> Self::Output

§Example

Implementors§

impl Sub for f16

type Output = f16

impl Sub for f32

type Output = f32

impl Sub for f64

type Output = f64

impl Sub for f128

type Output = f128

impl Sub for i8

type Output = i8

impl Sub for i16

type Output = i16

impl Sub for i32

type Output = i32

impl Sub for i64

type Output = i64

impl Sub for i128

type Output = i128

impl Sub for isize

type Output = isize

impl Sub for u8

type Output = u8

impl Sub for u16

type Output = u16

impl Sub for u32

type Output = u32

impl Sub for u64

type Output = u64

impl Sub for u128

type Output = u128

impl Sub for usize

type Output = usize

impl Sub for Assume

type Output = Assume

impl Sub for Saturating<i8>

type Output = Saturating<i8>

impl Sub for Saturating<i16>

type Output = Saturating<i16>

impl Sub for Saturating<i32>

type Output = Saturating<i32>

impl Sub for Saturating<i64>

type Output = Saturating<i64>

impl Sub for Saturating<i128>

type Output = Saturating<i128>

impl Sub for Saturating<isize>

type Output = Saturating<isize>

impl Sub for Saturating<u8>

type Output = Saturating<u8>

impl Sub for Saturating<u16>

type Output = Saturating<u16>

impl Sub for Saturating<u32>

type Output = Saturating<u32>

impl Sub for Saturating<u64>

type Output = Saturating<u64>

impl Sub for Saturating<u128>

type Output = Saturating<u128>

impl Sub for Saturating<usize>

type Output = Saturating<usize>

impl Sub for Wrapping<i8>

type Output = Wrapping<i8>

impl Sub for Wrapping<i16>

type Output = Wrapping<i16>

impl Sub for Wrapping<i32>

type Output = Wrapping<i32>

impl Sub for Wrapping<i64>

type Output = Wrapping<i64>

impl Sub for Wrapping<i128>

type Output = Wrapping<i128>

impl Sub for Wrapping<isize>

Trait Sub

§`Sub`tractable points

§Implementing `Sub` with generics