Trait ethers::core::k256::elliptic_curve::ops::Sub1.0.0[−][src]

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

Subtractable 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 });

Associated Types

The resulting type after applying the - operator.

Required methods

Performs the - operation.

Example
assert_eq!(12 - 1, 11);

Implementations on Foreign Types

Returns the difference of self and rhs as a new HashSet<T, S>.

Examples
use std::collections::HashSet;

let a: HashSet<_> = vec![1, 2, 3].into_iter().collect();
let b: HashSet<_> = vec![3, 4, 5].into_iter().collect();

let set = &a - &b;

let mut i = 0;
let expected = [1, 2];
for x in &set {
    assert!(expected.contains(x));
    i += 1;
}
assert_eq!(i, expected.len());

Returns the difference of self and rhs as a new BTreeSet<T>.

Examples
use std::collections::BTreeSet;

let a: BTreeSet<_> = vec![1, 2, 3].into_iter().collect();
let b: BTreeSet<_> = vec![3, 4, 5].into_iter().collect();

let result = &a - &b;
let result_vec: Vec<_> = result.into_iter().collect();
assert_eq!(result_vec, [1, 2]);

Returns the set difference, cloned into a new set.

Values are collected in the same order that they appear in self.

Returns the difference of self and rhs as a new HashSet<T, S>.

Examples
use hashbrown::HashSet;

let a: HashSet<_> = vec![1, 2, 3].into_iter().collect();
let b: HashSet<_> = vec![3, 4, 5].into_iter().collect();

let set = &a - &b;

let mut i = 0;
let expected = [1, 2];
for x in &set {
    assert!(expected.contains(x));
    i += 1;
}
assert_eq!(i, expected.len());

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Subtracts one BitVec from another assuming 2’s-complement encoding.

Subtraction is a more complex operation than addition. The bit-level work is largely the same, but semantic distinctions must be made. Unlike addition, which is commutative and tolerant of switching the order of the addends, subtraction cannot swap the minuend (LHS) and subtrahend (RHS).

Because of the properties of 2’s-complement arithmetic, M - S is equivalent to M + (!S + 1). Subtraction therefore bitflips the subtrahend and adds one. This may, in a degenerate case, cause the subtrahend to increase in length.

Once the subtrahend is stable, the minuend zero-extends its left side in order to match the length of the subtrahend if needed (this is provided by the >> operator).

When the minuend is stable, the minuend and subtrahend are added together by the <BitVec as Add> implementation. The output will be encoded in 2’s-complement, so a leading one means that the output is considered negative.

Interpreting the contents of a BitVec as an integer is beyond the scope of this crate.

Numeric arithmetic is provided on BitVec as a convenience. Serious numeric computation on variable-length integers should use the num_bigint crate instead, which is written specifically for that use case. BitVecs are not intended for arithmetic, and bitvec makes no guarantees about sustained correctness in arithmetic at this time.

Subtracts one BitVec from another.

Examples

Minuend larger than subtrahend, positive difference.

use bitvec::prelude::*;

let a = bitvec![1, 0];
let b = bitvec![   1];
let c = a - b;
assert_eq!(bitvec![0, 1], c);

Minuend smaller than subtrahend, negative difference.

use bitvec::prelude::*;

let a = bitvec![   1];
let b = bitvec![1, 0];
let c = a - b;
assert_eq!(bitvec![1, 1], c);

Subtraction from self is correctly handled.

use bitvec::prelude::*;

let a = bitvec![0, 1, 1, 0];
let b = a.clone();
let c = a - b;
assert!(c.not_any(), "{:?}", c);

A subtraction of Duration from NaiveTime wraps around and never overflows or underflows. In particular the addition ignores integral number of days. It is the same as the addition with a negated Duration.

As a part of Chrono’s leap second handling, the addition assumes that there is no leap second ever, except when the NaiveTime itself represents a leap second in which case the assumption becomes that there is exactly a single leap second ever.

Example

use chrono::{Duration, NaiveTime};

let from_hmsm = NaiveTime::from_hms_milli;

assert_eq!(from_hmsm(3, 5, 7, 0) - Duration::zero(),                  from_hmsm(3, 5, 7, 0));
assert_eq!(from_hmsm(3, 5, 7, 0) - Duration::seconds(1),              from_hmsm(3, 5, 6, 0));
assert_eq!(from_hmsm(3, 5, 7, 0) - Duration::seconds(60 + 5),         from_hmsm(3, 4, 2, 0));
assert_eq!(from_hmsm(3, 5, 7, 0) - Duration::seconds(2*60*60 + 6*60), from_hmsm(0, 59, 7, 0));
assert_eq!(from_hmsm(3, 5, 7, 0) - Duration::milliseconds(80),        from_hmsm(3, 5, 6, 920));
assert_eq!(from_hmsm(3, 5, 7, 950) - Duration::milliseconds(280),     from_hmsm(3, 5, 7, 670));

The subtraction wraps around.

assert_eq!(from_hmsm(3, 5, 7, 0) - Duration::seconds(8*60*60), from_hmsm(19, 5, 7, 0));
assert_eq!(from_hmsm(3, 5, 7, 0) - Duration::days(800),        from_hmsm(3, 5, 7, 0));

Leap seconds are handled, but the subtraction assumes that it is the only leap second happened.

let leap = from_hmsm(3, 5, 59, 1_300);
assert_eq!(leap - Duration::zero(),            from_hmsm(3, 5, 59, 1_300));
assert_eq!(leap - Duration::milliseconds(200), from_hmsm(3, 5, 59, 1_100));
assert_eq!(leap - Duration::milliseconds(500), from_hmsm(3, 5, 59, 800));
assert_eq!(leap - Duration::seconds(60),       from_hmsm(3, 5, 0, 300));
assert_eq!(leap - Duration::days(1),           from_hmsm(3, 6, 0, 300));

Subtracts another NaiveTime from the current time. Returns a Duration within +/- 1 day. This does not overflow or underflow at all.

As a part of Chrono’s leap second handling, the subtraction assumes that there is no leap second ever, except when any of the NaiveTimes themselves represents a leap second in which case the assumption becomes that there are exactly one (or two) leap second(s) ever.

The implementation is a wrapper around NaiveTime::signed_duration_since.

Example

use chrono::{Duration, NaiveTime};

let from_hmsm = NaiveTime::from_hms_milli;

assert_eq!(from_hmsm(3, 5, 7, 900) - from_hmsm(3, 5, 7, 900), Duration::zero());
assert_eq!(from_hmsm(3, 5, 7, 900) - from_hmsm(3, 5, 7, 875), Duration::milliseconds(25));
assert_eq!(from_hmsm(3, 5, 7, 900) - from_hmsm(3, 5, 6, 925), Duration::milliseconds(975));
assert_eq!(from_hmsm(3, 5, 7, 900) - from_hmsm(3, 5, 0, 900), Duration::seconds(7));
assert_eq!(from_hmsm(3, 5, 7, 900) - from_hmsm(3, 0, 7, 900), Duration::seconds(5 * 60));
assert_eq!(from_hmsm(3, 5, 7, 900) - from_hmsm(0, 5, 7, 900), Duration::seconds(3 * 3600));
assert_eq!(from_hmsm(3, 5, 7, 900) - from_hmsm(4, 5, 7, 900), Duration::seconds(-3600));
assert_eq!(from_hmsm(3, 5, 7, 900) - from_hmsm(2, 4, 6, 800),
           Duration::seconds(3600 + 60 + 1) + Duration::milliseconds(100));

Leap seconds are handled, but the subtraction assumes that there were no other leap seconds happened.

assert_eq!(from_hmsm(3, 0, 59, 1_000) - from_hmsm(3, 0, 59, 0), Duration::seconds(1));
assert_eq!(from_hmsm(3, 0, 59, 1_500) - from_hmsm(3, 0, 59, 0),
           Duration::milliseconds(1500));
assert_eq!(from_hmsm(3, 0, 59, 1_000) - from_hmsm(3, 0, 0, 0), Duration::seconds(60));
assert_eq!(from_hmsm(3, 0, 0, 0) - from_hmsm(2, 59, 59, 1_000), Duration::seconds(1));
assert_eq!(from_hmsm(3, 0, 59, 1_000) - from_hmsm(2, 59, 59, 1_000),
           Duration::seconds(61));

A subtraction of Duration from NaiveDateTime yields another NaiveDateTime. It is the same as the addition with a negated Duration.

As a part of Chrono’s leap second handling, the addition assumes that there is no leap second ever, except when the NaiveDateTime itself represents a leap second in which case the assumption becomes that there is exactly a single leap second ever.

Panics on underflow or overflow. Use NaiveDateTime::checked_sub_signed to detect that.

Example

use chrono::{Duration, NaiveDate};

let from_ymd = NaiveDate::from_ymd;

let d = from_ymd(2016, 7, 8);
let hms = |h, m, s| d.and_hms(h, m, s);
assert_eq!(hms(3, 5, 7) - Duration::zero(),             hms(3, 5, 7));
assert_eq!(hms(3, 5, 7) - Duration::seconds(1),         hms(3, 5, 6));
assert_eq!(hms(3, 5, 7) - Duration::seconds(-1),        hms(3, 5, 8));
assert_eq!(hms(3, 5, 7) - Duration::seconds(3600 + 60), hms(2, 4, 7));
assert_eq!(hms(3, 5, 7) - Duration::seconds(86_400),
           from_ymd(2016, 7, 7).and_hms(3, 5, 7));
assert_eq!(hms(3, 5, 7) - Duration::days(365),
           from_ymd(2015, 7, 9).and_hms(3, 5, 7));

let hmsm = |h, m, s, milli| d.and_hms_milli(h, m, s, milli);
assert_eq!(hmsm(3, 5, 7, 450) - Duration::milliseconds(670), hmsm(3, 5, 6, 780));

Leap seconds are handled, but the subtraction assumes that it is the only leap second happened.

let leap = hmsm(3, 5, 59, 1_300);
assert_eq!(leap - Duration::zero(),            hmsm(3, 5, 59, 1_300));
assert_eq!(leap - Duration::milliseconds(200), hmsm(3, 5, 59, 1_100));
assert_eq!(leap - Duration::milliseconds(500), hmsm(3, 5, 59, 800));
assert_eq!(leap - Duration::seconds(60),       hmsm(3, 5, 0, 300));
assert_eq!(leap - Duration::days(1),
           from_ymd(2016, 7, 7).and_hms_milli(3, 6, 0, 300));

Subtracts another NaiveDate from the current date. Returns a Duration of integral numbers.

This does not overflow or underflow at all, as all possible output fits in the range of Duration.

The implementation is a wrapper around NaiveDate::signed_duration_since.

Example

use chrono::{Duration, NaiveDate};

let from_ymd = NaiveDate::from_ymd;

assert_eq!(from_ymd(2014, 1, 1) - from_ymd(2014, 1, 1), Duration::zero());
assert_eq!(from_ymd(2014, 1, 1) - from_ymd(2013, 12, 31), Duration::days(1));
assert_eq!(from_ymd(2014, 1, 1) - from_ymd(2014, 1, 2), Duration::days(-1));
assert_eq!(from_ymd(2014, 1, 1) - from_ymd(2013, 9, 23), Duration::days(100));
assert_eq!(from_ymd(2014, 1, 1) - from_ymd(2013, 1, 1), Duration::days(365));
assert_eq!(from_ymd(2014, 1, 1) - from_ymd(2010, 1, 1), Duration::days(365*4 + 1));
assert_eq!(from_ymd(2014, 1, 1) - from_ymd(1614, 1, 1), Duration::days(365*400 + 97));

Subtracts another NaiveDateTime from the current date and time. This does not overflow or underflow at all.

As a part of Chrono’s leap second handling, the subtraction assumes that there is no leap second ever, except when any of the NaiveDateTimes themselves represents a leap second in which case the assumption becomes that there are exactly one (or two) leap second(s) ever.

The implementation is a wrapper around NaiveDateTime::signed_duration_since.

Example

use chrono::{Duration, NaiveDate};

let from_ymd = NaiveDate::from_ymd;

let d = from_ymd(2016, 7, 8);
assert_eq!(d.and_hms(3, 5, 7) - d.and_hms(2, 4, 6), Duration::seconds(3600 + 60 + 1));

// July 8 is 190th day in the year 2016
let d0 = from_ymd(2016, 1, 1);
assert_eq!(d.and_hms_milli(0, 7, 6, 500) - d0.and_hms(0, 0, 0),
           Duration::seconds(189 * 86_400 + 7 * 60 + 6) + Duration::milliseconds(500));

Leap seconds are handled, but the subtraction assumes that there were no other leap seconds happened.

let leap = from_ymd(2015, 6, 30).and_hms_milli(23, 59, 59, 1_500);
assert_eq!(leap - from_ymd(2015, 6, 30).and_hms(23, 0, 0),
           Duration::seconds(3600) + Duration::milliseconds(500));
assert_eq!(from_ymd(2015, 7, 1).and_hms(1, 0, 0) - leap,
           Duration::seconds(3600) - Duration::milliseconds(500));

A subtraction of Duration from NaiveDate discards the fractional days, rounding to the closest integral number of days towards Duration::zero(). It is the same as the addition with a negated Duration.

Panics on underflow or overflow. Use NaiveDate::checked_sub_signed to detect that.

Example

use chrono::{Duration, NaiveDate};

let from_ymd = NaiveDate::from_ymd;

assert_eq!(from_ymd(2014, 1, 1) - Duration::zero(),             from_ymd(2014, 1, 1));
assert_eq!(from_ymd(2014, 1, 1) - Duration::seconds(86399),     from_ymd(2014, 1, 1));
assert_eq!(from_ymd(2014, 1, 1) - Duration::seconds(-86399),    from_ymd(2014, 1, 1));
assert_eq!(from_ymd(2014, 1, 1) - Duration::days(1),            from_ymd(2013, 12, 31));
assert_eq!(from_ymd(2014, 1, 1) - Duration::days(-1),           from_ymd(2014, 1, 2));
assert_eq!(from_ymd(2014, 1, 1) - Duration::days(364),          from_ymd(2013, 1, 2));
assert_eq!(from_ymd(2014, 1, 1) - Duration::days(365*4 + 1),    from_ymd(2010, 1, 1));
assert_eq!(from_ymd(2014, 1, 1) - Duration::days(365*400 + 97), from_ymd(1614, 1, 1));

The resulting Tm is in UTC.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Returns the set difference of the two sets of flags.

Implementors

UTerm - B0 = Term

UInt<UTerm, B1> - B1 = UTerm

UTerm - UTerm = UTerm

Z0 - Z0 = Z0

UInt<U, B0> - B1 = UInt<U - B1, B1>

Z0 - N = P

Z0 - P = N

NInt - Z0 = NInt

PInt - Z0 = PInt

UInt - B0 = UInt

UInt<U, B1> - B1 = UInt<U, B0>

Subtracting unsigned integers. We just do our PrivateSub and then Trim the output.

N(Ul) - N(Ur): We resolve this with our PrivateAdd

P(Ul) - N(Ur) = P(Ul + Ur)

N(Ul) - P(Ur) = N(Ul + Ur)

P(Ul) - P(Ur): We resolve this with our PrivateAdd