diff --git a/src/libcore/ops.rs b/src/libcore/ops.rs index 9347ac2a8c82f..aefafa1b739cb 100644 --- a/src/libcore/ops.rs +++ b/src/libcore/ops.rs @@ -295,6 +295,37 @@ sub_impl! { usize u8 u16 u32 u64 isize i8 i16 i32 i64 f32 f64 } /// Foo * Foo; /// } /// ``` +/// +/// Note that `RHS = Self` by default, but this is not mandatory. Here is an +/// implementation which enables multiplication of vectors by scalars, as is +/// done in linear algebra. +/// +/// ``` +/// use std::ops::Mul; +/// +/// struct Scalar {value: usize}; +/// +/// #[derive(Debug)] +/// struct Vector {value: Vec}; +/// +/// impl Mul for Scalar { +/// type Output = Vector; +/// +/// fn mul(self, rhs: Vector) -> Vector { +/// Vector {value: rhs.value.iter().map(|v| self.value * v).collect()} +/// } +/// } +/// +/// impl PartialEq for Vector { +/// fn eq(&self, other: &Self) -> bool { +/// self.value == other.value +/// } +/// } +/// +/// let scalar = Scalar{value: 3}; +/// let vector = Vector{value: vec![2, 4, 6]}; +/// assert_eq!(scalar * vector, Vector{value: vec![6, 12, 18]}); +/// ``` #[lang = "mul"] #[stable(feature = "rust1", since = "1.0.0")] pub trait Mul { @@ -349,6 +380,37 @@ mul_impl! { usize u8 u16 u32 u64 isize i8 i16 i32 i64 f32 f64 } /// Foo / Foo; /// } /// ``` +/// +/// Note that `RHS = Self` by default, but this is not mandatory. Here is an +/// implementation which enables division of vectors by scalars, as is done in +/// linear algebra. +/// +/// ``` +/// use std::ops::Div; +/// +/// struct Scalar {value: f32}; +/// +/// #[derive(Debug)] +/// struct Vector {value: Vec}; +/// +/// impl Div for Vector { +/// type Output = Vector; +/// +/// fn div(self, rhs: Scalar) -> Vector { +/// Vector {value: self.value.iter().map(|v| v / rhs.value).collect()} +/// } +/// } +/// +/// impl PartialEq for Vector { +/// fn eq(&self, other: &Self) -> bool { +/// self.value == other.value +/// } +/// } +/// +/// let scalar = Scalar{value: 2f32}; +/// let vector = Vector{value: vec![2f32, 4f32, 6f32]}; +/// assert_eq!(vector / scalar, Vector{value: vec![1f32, 2f32, 3f32]}); +/// ``` #[lang = "div"] #[stable(feature = "rust1", since = "1.0.0")] pub trait Div {