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Rename truncate methods on integers to narrow #156974

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78 changes: 39 additions & 39 deletions library/core/src/num/int_macros.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -3985,83 +3985,83 @@ macro_rules! int_impl {
}
}

/// Truncate an integer to an integer of the same size or smaller, preserving the least
/// Narrow an integer to an integer of the same size or smaller, preserving the least
/// significant bits.
///
/// # Examples
///
/// ```
/// #![feature(integer_widen_truncate)]
#[doc = concat!("assert_eq!(120i8, 120", stringify!($SelfT), ".truncate());")]
#[doc = concat!("assert_eq!(-120i8, (-120", stringify!($SelfT), ").truncate());")]
/// assert_eq!(120i8, 376i32.truncate());
/// #![feature(integer_widen_narrow)]
#[doc = concat!("assert_eq!(120i8, 120", stringify!($SelfT), ".narrow());")]
#[doc = concat!("assert_eq!(-120i8, (-120", stringify!($SelfT), ").narrow());")]
/// assert_eq!(120i8, 376i32.narrow());
/// ```
#[must_use = "this returns the truncated value and does not modify the original"]
#[unstable(feature = "integer_widen_truncate", issue = "154330")]
#[rustc_const_unstable(feature = "integer_widen_truncate", issue = "154330")]
#[must_use = "this returns the narrowed value and does not modify the original"]
#[unstable(feature = "integer_widen_narrow", issue = "154330")]
#[rustc_const_unstable(feature = "integer_widen_narrow", issue = "154330")]
#[inline]
pub const fn truncate<Target>(self) -> Target
where Self: [const] traits::TruncateTarget<Target>
pub const fn narrow<Target>(self) -> Target
where Self: [const] traits::NarrowTarget<Target>
{
traits::TruncateTarget::internal_truncate(self)
traits::NarrowTarget::internal_narrow(self)
}

/// Truncate an integer to an integer of the same size or smaller, saturating at numeric bounds
/// instead of truncating.
/// Narrow an integer to an integer of the same size or smaller, saturating at numeric
/// bounds.
///
/// # Examples
///
/// ```
/// #![feature(integer_widen_truncate)]
#[doc = concat!("assert_eq!(120i8, 120", stringify!($SelfT), ".saturating_truncate());")]
#[doc = concat!("assert_eq!(-120i8, (-120", stringify!($SelfT), ").saturating_truncate());")]
/// assert_eq!(127i8, 376i32.saturating_truncate());
/// assert_eq!(-128i8, (-1000i32).saturating_truncate());
/// #![feature(integer_widen_narrow)]
#[doc = concat!("assert_eq!(120i8, 120", stringify!($SelfT), ".saturating_narrow());")]
#[doc = concat!("assert_eq!(-120i8, (-120", stringify!($SelfT), ").saturating_narrow());")]
/// assert_eq!(127i8, 376i32.saturating_narrow());
/// assert_eq!(-128i8, (-1000i32).saturating_narrow());
/// ```
#[must_use = "this returns the truncated value and does not modify the original"]
#[unstable(feature = "integer_widen_truncate", issue = "154330")]
#[rustc_const_unstable(feature = "integer_widen_truncate", issue = "154330")]
#[must_use = "this returns the narrowed value and does not modify the original"]
#[unstable(feature = "integer_widen_narrow", issue = "154330")]
#[rustc_const_unstable(feature = "integer_widen_narrow", issue = "154330")]
#[inline]
pub const fn saturating_truncate<Target>(self) -> Target
where Self: [const] traits::TruncateTarget<Target>
pub const fn saturating_narrow<Target>(self) -> Target
where Self: [const] traits::NarrowTarget<Target>
{
traits::TruncateTarget::internal_saturating_truncate(self)
traits::NarrowTarget::internal_saturating_narrow(self)
}

/// Truncate an integer to an integer of the same size or smaller, returning `None` if the value
/// Narrow an integer to an integer of the same size or smaller, returning `None` if the value
/// is outside the bounds of the smaller type.
///
/// # Examples
///
/// ```
/// #![feature(integer_widen_truncate)]
#[doc = concat!("assert_eq!(Some(120i8), 120", stringify!($SelfT), ".checked_truncate());")]
#[doc = concat!("assert_eq!(Some(-120i8), (-120", stringify!($SelfT), ").checked_truncate());")]
/// assert_eq!(None, 376i32.checked_truncate::<i8>());
/// assert_eq!(None, (-1000i32).checked_truncate::<i8>());
/// #![feature(integer_widen_narrow)]
#[doc = concat!("assert_eq!(Some(120i8), 120", stringify!($SelfT), ".checked_narrow());")]
#[doc = concat!("assert_eq!(Some(-120i8), (-120", stringify!($SelfT), ").checked_narrow());")]
/// assert_eq!(None, 376i32.checked_narrow::<i8>());
/// assert_eq!(None, (-1000i32).checked_narrow::<i8>());
/// ```
#[must_use = "this returns the truncated value and does not modify the original"]
#[unstable(feature = "integer_widen_truncate", issue = "154330")]
#[rustc_const_unstable(feature = "integer_widen_truncate", issue = "154330")]
#[must_use = "this returns the narrowed value and does not modify the original"]
#[unstable(feature = "integer_widen_narrow", issue = "154330")]
#[rustc_const_unstable(feature = "integer_widen_narrow", issue = "154330")]
#[inline]
pub const fn checked_truncate<Target>(self) -> Option<Target>
where Self: [const] traits::TruncateTarget<Target>
pub const fn checked_narrow<Target>(self) -> Option<Target>
where Self: [const] traits::NarrowTarget<Target>
{
traits::TruncateTarget::internal_checked_truncate(self)
traits::NarrowTarget::internal_checked_narrow(self)
}

/// Widen to an integer of the same size or larger, preserving its value.
///
/// # Examples
///
/// ```
/// #![feature(integer_widen_truncate)]
/// #![feature(integer_widen_narrow)]
#[doc = concat!("assert_eq!(120i128, 120i8.widen());")]
#[doc = concat!("assert_eq!(-120i128, (-120i8).widen());")]
/// ```
#[must_use = "this returns the widened value and does not modify the original"]
#[unstable(feature = "integer_widen_truncate", issue = "154330")]
#[rustc_const_unstable(feature = "integer_widen_truncate", issue = "154330")]
#[unstable(feature = "integer_widen_narrow", issue = "154330")]
#[rustc_const_unstable(feature = "integer_widen_narrow", issue = "154330")]
#[inline]
pub const fn widen<Target>(self) -> Target
where Self: [const] traits::WidenTarget<Target>
Expand Down
32 changes: 16 additions & 16 deletions library/core/src/num/traits.rs
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Original file line number Diff line number Diff line change
@@ -1,34 +1,34 @@
/// Definitions of traits for numeric types
// Implementation based on `num_conv` by jhpratt, under (MIT OR Apache-2.0).

/// Trait for types that this type can be truncated to
/// Trait for types that this type can be narrowed to
#[unstable(feature = "num_internals", reason = "internal implementation detail", issue = "none")]
#[rustc_const_unstable(feature = "integer_widen_truncate", issue = "154330")]
pub const trait TruncateTarget<Target>: crate::sealed::Sealed {
#[rustc_const_unstable(feature = "integer_widen_narrow", issue = "154330")]
pub const trait NarrowTarget<Target>: crate::sealed::Sealed {
#[doc(hidden)]
fn internal_truncate(self) -> Target;
fn internal_narrow(self) -> Target;

#[doc(hidden)]
fn internal_saturating_truncate(self) -> Target;
fn internal_saturating_narrow(self) -> Target;

#[doc(hidden)]
fn internal_checked_truncate(self) -> Option<Target>;
fn internal_checked_narrow(self) -> Option<Target>;
}

/// Trait for types that this type can be widened to
#[unstable(feature = "num_internals", reason = "internal implementation detail", issue = "none")]
#[rustc_const_unstable(feature = "integer_widen_truncate", issue = "154330")]
#[rustc_const_unstable(feature = "integer_widen_narrow", issue = "154330")]
pub const trait WidenTarget<Target>: crate::sealed::Sealed {
#[doc(hidden)]
fn internal_widen(self) -> Target;
}

macro_rules! impl_truncate {
macro_rules! impl_narrow {
($($from:ty => $($to:ty),+;)*) => {$($(
const _: () = assert!(
size_of::<$from>() >= size_of::<$to>(),
concat!(
"cannot truncate ",
"cannot narrow ",
stringify!($from),
" to ",
stringify!($to),
Expand All @@ -40,15 +40,15 @@ macro_rules! impl_truncate {
);

#[unstable(feature = "num_internals", reason = "internal implementation detail", issue = "none")]
#[rustc_const_unstable(feature = "integer_widen_truncate", issue = "154330")]
impl const TruncateTarget<$to> for $from {
#[rustc_const_unstable(feature = "integer_widen_narrow", issue = "154330")]
impl const NarrowTarget<$to> for $from {
#[inline]
fn internal_truncate(self) -> $to {
fn internal_narrow(self) -> $to {
self as _
}

#[inline]
fn internal_saturating_truncate(self) -> $to {
fn internal_saturating_narrow(self) -> $to {
if self > <$to>::MAX as Self {
<$to>::MAX
} else if self < <$to>::MIN as Self {
Expand All @@ -59,7 +59,7 @@ macro_rules! impl_truncate {
}

#[inline]
fn internal_checked_truncate(self) -> Option<$to> {
fn internal_checked_narrow(self) -> Option<$to> {
if self > <$to>::MAX as Self || self < <$to>::MIN as Self {
None
} else {
Expand Down Expand Up @@ -87,7 +87,7 @@ macro_rules! impl_widen {
);

#[unstable(feature = "num_internals", reason = "internal implementation detail", issue = "none")]
#[rustc_const_unstable(feature = "integer_widen_truncate", issue = "154330")]
#[rustc_const_unstable(feature = "integer_widen_narrow", issue = "154330")]
impl const WidenTarget<$to> for $from {
fn internal_widen(self) -> $to {
self as _
Expand All @@ -96,7 +96,7 @@ macro_rules! impl_widen {
)+)*};
}

impl_truncate! {
impl_narrow! {
u8 => u8;
u16 => u16, u8;
u32 => u32, u16, u8;
Expand Down
70 changes: 35 additions & 35 deletions library/core/src/num/uint_macros.rs
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Expand Up @@ -4152,77 +4152,77 @@ macro_rules! uint_impl {
#[rustc_diagnostic_item = concat!(stringify!($SelfT), "_legacy_fn_max_value")]
pub const fn max_value() -> Self { Self::MAX }

/// Truncate an integer to an integer of the same size or smaller, preserving the least
/// Narrow an integer to an integer of the same size or smaller, preserving the least
/// significant bits.
///
/// # Examples
///
/// ```
/// #![feature(integer_widen_truncate)]
#[doc = concat!("assert_eq!(120u8, 120", stringify!($SelfT), ".truncate());")]
/// assert_eq!(120u8, 376u32.truncate());
/// #![feature(integer_widen_narrow)]
#[doc = concat!("assert_eq!(120u8, 120", stringify!($SelfT), ".narrow());")]
/// assert_eq!(120u8, 376u32.narrow());
/// ```
#[must_use = "this returns the truncated value and does not modify the original"]
#[unstable(feature = "integer_widen_truncate", issue = "154330")]
#[rustc_const_unstable(feature = "integer_widen_truncate", issue = "154330")]
#[must_use = "this returns the narrowed value and does not modify the original"]
#[unstable(feature = "integer_widen_narrow", issue = "154330")]
#[rustc_const_unstable(feature = "integer_widen_narrow", issue = "154330")]
#[inline]
pub const fn truncate<Target>(self) -> Target
where Self: [const] traits::TruncateTarget<Target>
pub const fn narrow<Target>(self) -> Target
where Self: [const] traits::NarrowTarget<Target>
{
traits::TruncateTarget::internal_truncate(self)
traits::NarrowTarget::internal_narrow(self)
}

/// Truncate an integer to an integer of the same size or smaller, saturating at numeric bounds
/// instead of truncating.
/// Narrow an integer to an integer of the same size or smaller, saturating at numeric
/// bounds.
///
/// # Examples
///
/// ```
/// #![feature(integer_widen_truncate)]
#[doc = concat!("assert_eq!(120u8, 120", stringify!($SelfT), ".saturating_truncate());")]
/// assert_eq!(255u8, 376u32.saturating_truncate());
/// #![feature(integer_widen_narrow)]
#[doc = concat!("assert_eq!(120u8, 120", stringify!($SelfT), ".saturating_narrow());")]
/// assert_eq!(255u8, 376u32.saturating_narrow());
/// ```
#[must_use = "this returns the truncated value and does not modify the original"]
#[unstable(feature = "integer_widen_truncate", issue = "154330")]
#[rustc_const_unstable(feature = "integer_widen_truncate", issue = "154330")]
#[must_use = "this returns the narrowed value and does not modify the original"]
#[unstable(feature = "integer_widen_narrow", issue = "154330")]
#[rustc_const_unstable(feature = "integer_widen_narrow", issue = "154330")]
#[inline]
pub const fn saturating_truncate<Target>(self) -> Target
where Self: [const] traits::TruncateTarget<Target>
pub const fn saturating_narrow<Target>(self) -> Target
where Self: [const] traits::NarrowTarget<Target>
{
traits::TruncateTarget::internal_saturating_truncate(self)
traits::NarrowTarget::internal_saturating_narrow(self)
}

/// Truncate an integer to an integer of the same size or smaller, returning `None` if the value
/// is outside the bounds of the smaller type.
/// Narrow an integer to an integer of the same size or smaller, returning `None` if the
/// value is outside the bounds of the smaller type.
///
/// # Examples
///
/// ```
/// #![feature(integer_widen_truncate)]
#[doc = concat!("assert_eq!(Some(120u8), 120", stringify!($SelfT), ".checked_truncate());")]
/// assert_eq!(None, 376u32.checked_truncate::<u8>());
/// #![feature(integer_widen_narrow)]
#[doc = concat!("assert_eq!(Some(120u8), 120", stringify!($SelfT), ".checked_narrow());")]
/// assert_eq!(None, 376u32.checked_narrow::<u8>());
/// ```
#[must_use = "this returns the truncated value and does not modify the original"]
#[unstable(feature = "integer_widen_truncate", issue = "154330")]
#[rustc_const_unstable(feature = "integer_widen_truncate", issue = "154330")]
#[must_use = "this returns the narrowed value and does not modify the original"]
#[unstable(feature = "integer_widen_narrow", issue = "154330")]
#[rustc_const_unstable(feature = "integer_widen_narrow", issue = "154330")]
#[inline]
pub const fn checked_truncate<Target>(self) -> Option<Target>
where Self: [const] traits::TruncateTarget<Target>
pub const fn checked_narrow<Target>(self) -> Option<Target>
where Self: [const] traits::NarrowTarget<Target>
{
traits::TruncateTarget::internal_checked_truncate(self)
traits::NarrowTarget::internal_checked_narrow(self)
}

/// Widen to an integer of the same size or larger, preserving its value.
///
/// # Examples
///
/// ```
/// #![feature(integer_widen_truncate)]
/// #![feature(integer_widen_narrow)]
#[doc = concat!("assert_eq!(120u128, 120u8.widen());")]
/// ```
#[must_use = "this returns the widened value and does not modify the original"]
#[unstable(feature = "integer_widen_truncate", issue = "154330")]
#[rustc_const_unstable(feature = "integer_widen_truncate", issue = "154330")]
#[unstable(feature = "integer_widen_narrow", issue = "154330")]
#[rustc_const_unstable(feature = "integer_widen_narrow", issue = "154330")]
#[inline]
pub const fn widen<Target>(self) -> Target
where Self: [const] traits::WidenTarget<Target>
Expand Down
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