Trait ethers::core::k256::elliptic_curve::ops::Add1.0.0[−][src]

pub trait Add<Rhs = Self> {
    type Output;
    fn add(self, rhs: Rhs) -> Self::Output;
}
Expand description

The addition operator +.

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

Examples

Addable points

use std::ops::Add;

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

impl Add for Point {
    type Output = Self;

    fn add(self, other: Self) -> Self {
        Self {
            x: self.x + other.x,
            y: self.y + other.y,
        }
    }
}

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

Implementing Add with generics

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

use std::ops::Add;

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

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

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

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

Associated Types

The resulting type after applying the + operator.

Required methods

Performs the + operation.

Example
assert_eq!(12 + 1, 13);

Implementations on Foreign Types

Panics

This function may panic if the resulting point in time cannot be represented by the underlying data structure. See Instant::checked_add for a version without panic.

Panics

This function may panic if the resulting point in time cannot be represented by the underlying data structure. See SystemTime::checked_add for a version without panic.

Implements the + operator for concatenating two strings.

This consumes the String on the left-hand side and re-uses its buffer (growing it if necessary). This is done to avoid allocating a new String and copying the entire contents on every operation, which would lead to O(n^2) running time when building an n-byte string by repeated concatenation.

The string on the right-hand side is only borrowed; its contents are copied into the returned String.

Examples

Concatenating two Strings takes the first by value and borrows the second:

let a = String::from("hello");
let b = String::from(" world");
let c = a + &b;
// `a` is moved and can no longer be used here.

If you want to keep using the first String, you can clone it and append to the clone instead:

let a = String::from("hello");
let b = String::from(" world");
let c = a.clone() + &b;
// `a` is still valid here.

Concatenating &str slices can be done by converting the first to a String:

let a = "hello";
let b = " world";
let c = a.to_string() + b;

Adds two BitVecs together, zero-extending the shorter.

BitVec addition works just like adding numbers longhand on paper. The first bits in the BitVec are the highest, so addition works from right to left, and the shorter BitVec is assumed to be extended to the left with zero.

The output BitVec may be one bit longer than the longer input, if addition overflowed.

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.

Adds two BitVecs.

Examples
use bitvec::prelude::*;

let a = bitvec![0, 1, 0, 1];
let b = bitvec![0, 0, 1, 1];
let s = a + b;
assert_eq!(bitvec![1, 0, 0, 0], s);

This example demonstrates the addition of differently-sized BitVecs, and will overflow.

use bitvec::prelude::*;

let a = bitvec![1; 4];
let b = bitvec![1; 1];
let s = b + a;
assert_eq!(bitvec![1, 0, 0, 0, 0], s);

An addition of Duration to NaiveDate discards the fractional days, rounding to the closest integral number of days towards Duration::zero().

Panics on underflow or overflow. Use NaiveDate::checked_add_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(2014, 1, 2));
assert_eq!(from_ymd(2014, 1, 1) + Duration::days(-1),           from_ymd(2013, 12, 31));
assert_eq!(from_ymd(2014, 1, 1) + Duration::days(364),          from_ymd(2014, 12, 31));
assert_eq!(from_ymd(2014, 1, 1) + Duration::days(365*4 + 1),    from_ymd(2018, 1, 1));
assert_eq!(from_ymd(2014, 1, 1) + Duration::days(365*400 + 97), from_ymd(2414, 1, 1));

An addition of Duration to NaiveDateTime yields another NaiveDateTime.

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_add_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, 8));
assert_eq!(hms(3, 5, 7) + Duration::seconds(-1),        hms(3, 5, 6));
assert_eq!(hms(3, 5, 7) + Duration::seconds(3600 + 60), hms(4, 6, 7));
assert_eq!(hms(3, 5, 7) + Duration::seconds(86_400),
           from_ymd(2016, 7, 9).and_hms(3, 5, 7));
assert_eq!(hms(3, 5, 7) + Duration::days(365),
           from_ymd(2017, 7, 8).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, 980) + Duration::milliseconds(450), hmsm(3, 5, 8, 430));

Leap seconds are handled, but the addition 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(-500), hmsm(3, 5, 59, 800));
assert_eq!(leap + Duration::milliseconds(500),  hmsm(3, 5, 59, 1_800));
assert_eq!(leap + Duration::milliseconds(800),  hmsm(3, 6, 0, 100));
assert_eq!(leap + Duration::seconds(10),        hmsm(3, 6, 9, 300));
assert_eq!(leap + Duration::seconds(-10),       hmsm(3, 5, 50, 300));
assert_eq!(leap + Duration::days(1),
           from_ymd(2016, 7, 9).and_hms_milli(3, 5, 59, 300));

An addition of Duration to NaiveTime wraps around and never overflows or underflows. In particular the addition ignores integral number of days.

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, 8, 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 + 4),         from_hmsm(3, 6, 11, 0));
assert_eq!(from_hmsm(3, 5, 7, 0) + Duration::seconds(7*60*60 - 6*60), from_hmsm(9, 59, 7, 0));
assert_eq!(from_hmsm(3, 5, 7, 0) + Duration::milliseconds(80),        from_hmsm(3, 5, 7, 80));
assert_eq!(from_hmsm(3, 5, 7, 950) + Duration::milliseconds(280),     from_hmsm(3, 5, 8, 230));
assert_eq!(from_hmsm(3, 5, 7, 950) + Duration::milliseconds(-980),    from_hmsm(3, 5, 6, 970));

The addition wraps around.

assert_eq!(from_hmsm(3, 5, 7, 0) + Duration::seconds(22*60*60), from_hmsm(1, 5, 7, 0));
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 addition 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(-500), from_hmsm(3, 5, 59, 800));
assert_eq!(leap + Duration::milliseconds(500),  from_hmsm(3, 5, 59, 1_800));
assert_eq!(leap + Duration::milliseconds(800),  from_hmsm(3, 6, 0, 100));
assert_eq!(leap + Duration::seconds(10),        from_hmsm(3, 6, 9, 300));
assert_eq!(leap + Duration::seconds(-10),       from_hmsm(3, 5, 50, 300));
assert_eq!(leap + Duration::days(1),            from_hmsm(3, 5, 59, 300));

The resulting Tm is in UTC.

Implementors

UTerm + B0 = UTerm

UTerm + B1 = UInt<UTerm, B1>

Z0 + I = I

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

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

NInt + Z0 = NInt

PInt + Z0 = PInt

UTerm + U = U

U + B0 = U

UInt<U, B> + UTerm = UInt<U, B>

N(Ul) + N(Ur) = N(Ul + Ur)

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

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

P(Ul) + P(Ur) = P(Ul + Ur)

UInt<Ul, B0> + UInt<Ur, B0> = UInt<Ul + Ur, B0>

UInt<Ul, B1> + UInt<Ur, B0> = UInt<Ul + Ur, B1>

UInt<Ul, B0> + UInt<Ur, B1> = UInt<Ul + Ur, B1>

UInt<Ul, B1> + UInt<Ur, B1> = UInt<(Ul + Ur) + B1, B0>