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Move rounding discussion to integer Div/Rem impls
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wthrowe committed Jul 13, 2015
1 parent 218eb12 commit 7824956
Showing 1 changed file with 22 additions and 8 deletions.
30 changes: 22 additions & 8 deletions src/libcore/ops.rs
Expand Up @@ -315,9 +315,6 @@ mul_impl! { usize u8 u16 u32 u64 isize i8 i16 i32 i64 f32 f64 }

/// The `Div` trait is used to specify the functionality of `/`.
///
/// For primitive integral types, this operation rounds towards zero,
/// truncating any fractional part of the exact result.
///
/// # Examples
///
/// A trivial implementation of `Div`. When `Foo / Foo` happens, it ends up
Expand Down Expand Up @@ -354,7 +351,25 @@ pub trait Div<RHS=Self> {
fn div(self, rhs: RHS) -> Self::Output;
}

macro_rules! div_impl {
macro_rules! div_impl_integer {
($($t:ty)*) => ($(
/// This operation rounds towards zero, truncating any
/// fractional part of the exact result.
#[stable(feature = "rust1", since = "1.0.0")]
impl Div for $t {
type Output = $t;

#[inline]
fn div(self, other: $t) -> $t { self / other }
}

forward_ref_binop! { impl Div, div for $t, $t }
)*)
}

div_impl_integer! { usize u8 u16 u32 u64 isize i8 i16 i32 i64 }

macro_rules! div_impl_float {
($($t:ty)*) => ($(
#[stable(feature = "rust1", since = "1.0.0")]
impl Div for $t {
Expand All @@ -368,13 +383,10 @@ macro_rules! div_impl {
)*)
}

div_impl! { usize u8 u16 u32 u64 isize i8 i16 i32 i64 f32 f64 }
div_impl_float! { f32 f64 }

/// The `Rem` trait is used to specify the functionality of `%`.
///
/// For primitive integral types, this operation satisfies `n % d == n
/// - (n / d) * d`. The result has the same sign as the left operand.
///
/// # Examples
///
/// A trivial implementation of `Rem`. When `Foo % Foo` happens, it ends up
Expand Down Expand Up @@ -413,6 +425,8 @@ pub trait Rem<RHS=Self> {

macro_rules! rem_impl {
($($t:ty)*) => ($(
/// This operation satisfies `n % d == n - (n / d) * d`. The
/// result has the same sign as the left operand.
#[stable(feature = "rust1", since = "1.0.0")]
impl Rem for $t {
type Output = $t;
Expand Down

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