Trait std::ops::Add 1.0.0[−][src]
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 });Run
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 });Run
Associated Types
Loading content...Required methods
Loading content...Implementors
impl Add<Duration> for SystemTime1.8.0[src]
impl Add<Duration> for SystemTime1.8.0[src]type Output = SystemTime
fn add(self, dur: Duration) -> SystemTime[src]
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.
impl<'_> Add<&'_ str> for String[src]
impl<'_> Add<&'_ str> for String[src]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.Run
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.Run
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;Run