| use crate::fmt; |
| use crate::hash::Hash; |
| use crate::slice::index::{ |
| slice_end_index_len_fail, slice_end_index_overflow_fail, slice_index_order_fail, |
| slice_start_index_overflow_fail, |
| }; |
| |
| /// An unbounded range (`..`). |
| /// |
| /// `RangeFull` is primarily used as a [slicing index], its shorthand is `..`. |
| /// It cannot serve as an [`Iterator`] because it doesn't have a starting point. |
| /// |
| /// # Examples |
| /// |
| /// The `..` syntax is a `RangeFull`: |
| /// |
| /// ``` |
| /// assert_eq!((..), std::ops::RangeFull); |
| /// ``` |
| /// |
| /// It does not have an [`IntoIterator`] implementation, so you can't use it in |
| /// a `for` loop directly. This won't compile: |
| /// |
| /// ```compile_fail,E0277 |
| /// for i in .. { |
| /// // ... |
| /// } |
| /// ``` |
| /// |
| /// Used as a [slicing index], `RangeFull` produces the full array as a slice. |
| /// |
| /// ``` |
| /// let arr = [0, 1, 2, 3, 4]; |
| /// assert_eq!(arr[ .. ], [0, 1, 2, 3, 4]); // This is the `RangeFull` |
| /// assert_eq!(arr[ .. 3], [0, 1, 2 ]); |
| /// assert_eq!(arr[ ..=3], [0, 1, 2, 3 ]); |
| /// assert_eq!(arr[1.. ], [ 1, 2, 3, 4]); |
| /// assert_eq!(arr[1.. 3], [ 1, 2 ]); |
| /// assert_eq!(arr[1..=3], [ 1, 2, 3 ]); |
| /// ``` |
| /// |
| /// [slicing index]: crate::slice::SliceIndex |
| #[lang = "RangeFull"] |
| #[doc(alias = "..")] |
| #[derive(Copy, Clone, Default, PartialEq, Eq, Hash)] |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub struct RangeFull; |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl fmt::Debug for RangeFull { |
| fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { |
| write!(fmt, "..") |
| } |
| } |
| |
| /// A (half-open) range bounded inclusively below and exclusively above |
| /// (`start..end`). |
| /// |
| /// The range `start..end` contains all values with `start <= x < end`. |
| /// It is empty if `start >= end`. |
| /// |
| /// # Examples |
| /// |
| /// The `start..end` syntax is a `Range`: |
| /// |
| /// ``` |
| /// assert_eq!((3..5), std::ops::Range { start: 3, end: 5 }); |
| /// assert_eq!(3 + 4 + 5, (3..6).sum()); |
| /// ``` |
| /// |
| /// ``` |
| /// let arr = [0, 1, 2, 3, 4]; |
| /// assert_eq!(arr[ .. ], [0, 1, 2, 3, 4]); |
| /// assert_eq!(arr[ .. 3], [0, 1, 2 ]); |
| /// assert_eq!(arr[ ..=3], [0, 1, 2, 3 ]); |
| /// assert_eq!(arr[1.. ], [ 1, 2, 3, 4]); |
| /// assert_eq!(arr[1.. 3], [ 1, 2 ]); // This is a `Range` |
| /// assert_eq!(arr[1..=3], [ 1, 2, 3 ]); |
| /// ``` |
| #[lang = "Range"] |
| #[doc(alias = "..")] |
| #[derive(Clone, Default, PartialEq, Eq, Hash)] // not Copy -- see #27186 |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub struct Range<Idx> { |
| /// The lower bound of the range (inclusive). |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub start: Idx, |
| /// The upper bound of the range (exclusive). |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub end: Idx, |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<Idx: fmt::Debug> fmt::Debug for Range<Idx> { |
| fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { |
| self.start.fmt(fmt)?; |
| write!(fmt, "..")?; |
| self.end.fmt(fmt)?; |
| Ok(()) |
| } |
| } |
| |
| impl<Idx: PartialOrd<Idx>> Range<Idx> { |
| /// Returns `true` if `item` is contained in the range. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// assert!(!(3..5).contains(&2)); |
| /// assert!( (3..5).contains(&3)); |
| /// assert!( (3..5).contains(&4)); |
| /// assert!(!(3..5).contains(&5)); |
| /// |
| /// assert!(!(3..3).contains(&3)); |
| /// assert!(!(3..2).contains(&3)); |
| /// |
| /// assert!( (0.0..1.0).contains(&0.5)); |
| /// assert!(!(0.0..1.0).contains(&f32::NAN)); |
| /// assert!(!(0.0..f32::NAN).contains(&0.5)); |
| /// assert!(!(f32::NAN..1.0).contains(&0.5)); |
| /// ``` |
| #[stable(feature = "range_contains", since = "1.35.0")] |
| pub fn contains<U>(&self, item: &U) -> bool |
| where |
| Idx: PartialOrd<U>, |
| U: ?Sized + PartialOrd<Idx>, |
| { |
| <Self as RangeBounds<Idx>>::contains(self, item) |
| } |
| |
| /// Returns `true` if the range contains no items. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// assert!(!(3..5).is_empty()); |
| /// assert!( (3..3).is_empty()); |
| /// assert!( (3..2).is_empty()); |
| /// ``` |
| /// |
| /// The range is empty if either side is incomparable: |
| /// |
| /// ``` |
| /// assert!(!(3.0..5.0).is_empty()); |
| /// assert!( (3.0..f32::NAN).is_empty()); |
| /// assert!( (f32::NAN..5.0).is_empty()); |
| /// ``` |
| #[stable(feature = "range_is_empty", since = "1.47.0")] |
| pub fn is_empty(&self) -> bool { |
| !(self.start < self.end) |
| } |
| } |
| |
| /// A range only bounded inclusively below (`start..`). |
| /// |
| /// The `RangeFrom` `start..` contains all values with `x >= start`. |
| /// |
| /// *Note*: Overflow in the [`Iterator`] implementation (when the contained |
| /// data type reaches its numerical limit) is allowed to panic, wrap, or |
| /// saturate. This behavior is defined by the implementation of the [`Step`] |
| /// trait. For primitive integers, this follows the normal rules, and respects |
| /// the overflow checks profile (panic in debug, wrap in release). Note also |
| /// that overflow happens earlier than you might assume: the overflow happens |
| /// in the call to `next` that yields the maximum value, as the range must be |
| /// set to a state to yield the next value. |
| /// |
| /// [`Step`]: crate::iter::Step |
| /// |
| /// # Examples |
| /// |
| /// The `start..` syntax is a `RangeFrom`: |
| /// |
| /// ``` |
| /// assert_eq!((2..), std::ops::RangeFrom { start: 2 }); |
| /// assert_eq!(2 + 3 + 4, (2..).take(3).sum()); |
| /// ``` |
| /// |
| /// ``` |
| /// let arr = [0, 1, 2, 3, 4]; |
| /// assert_eq!(arr[ .. ], [0, 1, 2, 3, 4]); |
| /// assert_eq!(arr[ .. 3], [0, 1, 2 ]); |
| /// assert_eq!(arr[ ..=3], [0, 1, 2, 3 ]); |
| /// assert_eq!(arr[1.. ], [ 1, 2, 3, 4]); // This is a `RangeFrom` |
| /// assert_eq!(arr[1.. 3], [ 1, 2 ]); |
| /// assert_eq!(arr[1..=3], [ 1, 2, 3 ]); |
| /// ``` |
| #[lang = "RangeFrom"] |
| #[doc(alias = "..")] |
| #[derive(Clone, PartialEq, Eq, Hash)] // not Copy -- see #27186 |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub struct RangeFrom<Idx> { |
| /// The lower bound of the range (inclusive). |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub start: Idx, |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<Idx: fmt::Debug> fmt::Debug for RangeFrom<Idx> { |
| fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { |
| self.start.fmt(fmt)?; |
| write!(fmt, "..")?; |
| Ok(()) |
| } |
| } |
| |
| impl<Idx: PartialOrd<Idx>> RangeFrom<Idx> { |
| /// Returns `true` if `item` is contained in the range. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// assert!(!(3..).contains(&2)); |
| /// assert!( (3..).contains(&3)); |
| /// assert!( (3..).contains(&1_000_000_000)); |
| /// |
| /// assert!( (0.0..).contains(&0.5)); |
| /// assert!(!(0.0..).contains(&f32::NAN)); |
| /// assert!(!(f32::NAN..).contains(&0.5)); |
| /// ``` |
| #[stable(feature = "range_contains", since = "1.35.0")] |
| pub fn contains<U>(&self, item: &U) -> bool |
| where |
| Idx: PartialOrd<U>, |
| U: ?Sized + PartialOrd<Idx>, |
| { |
| <Self as RangeBounds<Idx>>::contains(self, item) |
| } |
| } |
| |
| /// A range only bounded exclusively above (`..end`). |
| /// |
| /// The `RangeTo` `..end` contains all values with `x < end`. |
| /// It cannot serve as an [`Iterator`] because it doesn't have a starting point. |
| /// |
| /// # Examples |
| /// |
| /// The `..end` syntax is a `RangeTo`: |
| /// |
| /// ``` |
| /// assert_eq!((..5), std::ops::RangeTo { end: 5 }); |
| /// ``` |
| /// |
| /// It does not have an [`IntoIterator`] implementation, so you can't use it in |
| /// a `for` loop directly. This won't compile: |
| /// |
| /// ```compile_fail,E0277 |
| /// // error[E0277]: the trait bound `std::ops::RangeTo<{integer}>: |
| /// // std::iter::Iterator` is not satisfied |
| /// for i in ..5 { |
| /// // ... |
| /// } |
| /// ``` |
| /// |
| /// When used as a [slicing index], `RangeTo` produces a slice of all array |
| /// elements before the index indicated by `end`. |
| /// |
| /// ``` |
| /// let arr = [0, 1, 2, 3, 4]; |
| /// assert_eq!(arr[ .. ], [0, 1, 2, 3, 4]); |
| /// assert_eq!(arr[ .. 3], [0, 1, 2 ]); // This is a `RangeTo` |
| /// assert_eq!(arr[ ..=3], [0, 1, 2, 3 ]); |
| /// assert_eq!(arr[1.. ], [ 1, 2, 3, 4]); |
| /// assert_eq!(arr[1.. 3], [ 1, 2 ]); |
| /// assert_eq!(arr[1..=3], [ 1, 2, 3 ]); |
| /// ``` |
| /// |
| /// [slicing index]: crate::slice::SliceIndex |
| #[lang = "RangeTo"] |
| #[doc(alias = "..")] |
| #[derive(Copy, Clone, PartialEq, Eq, Hash)] |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub struct RangeTo<Idx> { |
| /// The upper bound of the range (exclusive). |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub end: Idx, |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<Idx: fmt::Debug> fmt::Debug for RangeTo<Idx> { |
| fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { |
| write!(fmt, "..")?; |
| self.end.fmt(fmt)?; |
| Ok(()) |
| } |
| } |
| |
| impl<Idx: PartialOrd<Idx>> RangeTo<Idx> { |
| /// Returns `true` if `item` is contained in the range. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// assert!( (..5).contains(&-1_000_000_000)); |
| /// assert!( (..5).contains(&4)); |
| /// assert!(!(..5).contains(&5)); |
| /// |
| /// assert!( (..1.0).contains(&0.5)); |
| /// assert!(!(..1.0).contains(&f32::NAN)); |
| /// assert!(!(..f32::NAN).contains(&0.5)); |
| /// ``` |
| #[stable(feature = "range_contains", since = "1.35.0")] |
| pub fn contains<U>(&self, item: &U) -> bool |
| where |
| Idx: PartialOrd<U>, |
| U: ?Sized + PartialOrd<Idx>, |
| { |
| <Self as RangeBounds<Idx>>::contains(self, item) |
| } |
| } |
| |
| /// A range bounded inclusively below and above (`start..=end`). |
| /// |
| /// The `RangeInclusive` `start..=end` contains all values with `x >= start` |
| /// and `x <= end`. It is empty unless `start <= end`. |
| /// |
| /// This iterator is [fused], but the specific values of `start` and `end` after |
| /// iteration has finished are **unspecified** other than that [`.is_empty()`] |
| /// will return `true` once no more values will be produced. |
| /// |
| /// [fused]: crate::iter::FusedIterator |
| /// [`.is_empty()`]: RangeInclusive::is_empty |
| /// |
| /// # Examples |
| /// |
| /// The `start..=end` syntax is a `RangeInclusive`: |
| /// |
| /// ``` |
| /// assert_eq!((3..=5), std::ops::RangeInclusive::new(3, 5)); |
| /// assert_eq!(3 + 4 + 5, (3..=5).sum()); |
| /// ``` |
| /// |
| /// ``` |
| /// let arr = [0, 1, 2, 3, 4]; |
| /// assert_eq!(arr[ .. ], [0, 1, 2, 3, 4]); |
| /// assert_eq!(arr[ .. 3], [0, 1, 2 ]); |
| /// assert_eq!(arr[ ..=3], [0, 1, 2, 3 ]); |
| /// assert_eq!(arr[1.. ], [ 1, 2, 3, 4]); |
| /// assert_eq!(arr[1.. 3], [ 1, 2 ]); |
| /// assert_eq!(arr[1..=3], [ 1, 2, 3 ]); // This is a `RangeInclusive` |
| /// ``` |
| #[lang = "RangeInclusive"] |
| #[doc(alias = "..=")] |
| #[derive(Clone, PartialEq, Eq, Hash)] // not Copy -- see #27186 |
| #[stable(feature = "inclusive_range", since = "1.26.0")] |
| pub struct RangeInclusive<Idx> { |
| // Note that the fields here are not public to allow changing the |
| // representation in the future; in particular, while we could plausibly |
| // expose start/end, modifying them without changing (future/current) |
| // private fields may lead to incorrect behavior, so we don't want to |
| // support that mode. |
| pub(crate) start: Idx, |
| pub(crate) end: Idx, |
| |
| // This field is: |
| // - `false` upon construction |
| // - `false` when iteration has yielded an element and the iterator is not exhausted |
| // - `true` when iteration has been used to exhaust the iterator |
| // |
| // This is required to support PartialEq and Hash without a PartialOrd bound or specialization. |
| pub(crate) exhausted: bool, |
| } |
| |
| impl<Idx> RangeInclusive<Idx> { |
| /// Creates a new inclusive range. Equivalent to writing `start..=end`. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// use std::ops::RangeInclusive; |
| /// |
| /// assert_eq!(3..=5, RangeInclusive::new(3, 5)); |
| /// ``` |
| #[lang = "range_inclusive_new"] |
| #[stable(feature = "inclusive_range_methods", since = "1.27.0")] |
| #[inline] |
| #[rustc_promotable] |
| #[rustc_const_stable(feature = "const_range_new", since = "1.32.0")] |
| pub const fn new(start: Idx, end: Idx) -> Self { |
| Self { start, end, exhausted: false } |
| } |
| |
| /// Returns the lower bound of the range (inclusive). |
| /// |
| /// When using an inclusive range for iteration, the values of `start()` and |
| /// [`end()`] are unspecified after the iteration ended. To determine |
| /// whether the inclusive range is empty, use the [`is_empty()`] method |
| /// instead of comparing `start() > end()`. |
| /// |
| /// Note: the value returned by this method is unspecified after the range |
| /// has been iterated to exhaustion. |
| /// |
| /// [`end()`]: RangeInclusive::end |
| /// [`is_empty()`]: RangeInclusive::is_empty |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// assert_eq!((3..=5).start(), &3); |
| /// ``` |
| #[stable(feature = "inclusive_range_methods", since = "1.27.0")] |
| #[rustc_const_stable(feature = "const_inclusive_range_methods", since = "1.32.0")] |
| #[inline] |
| pub const fn start(&self) -> &Idx { |
| &self.start |
| } |
| |
| /// Returns the upper bound of the range (inclusive). |
| /// |
| /// When using an inclusive range for iteration, the values of [`start()`] |
| /// and `end()` are unspecified after the iteration ended. To determine |
| /// whether the inclusive range is empty, use the [`is_empty()`] method |
| /// instead of comparing `start() > end()`. |
| /// |
| /// Note: the value returned by this method is unspecified after the range |
| /// has been iterated to exhaustion. |
| /// |
| /// [`start()`]: RangeInclusive::start |
| /// [`is_empty()`]: RangeInclusive::is_empty |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// assert_eq!((3..=5).end(), &5); |
| /// ``` |
| #[stable(feature = "inclusive_range_methods", since = "1.27.0")] |
| #[rustc_const_stable(feature = "const_inclusive_range_methods", since = "1.32.0")] |
| #[inline] |
| pub const fn end(&self) -> &Idx { |
| &self.end |
| } |
| |
| /// Destructures the `RangeInclusive` into (lower bound, upper (inclusive) bound). |
| /// |
| /// Note: the value returned by this method is unspecified after the range |
| /// has been iterated to exhaustion. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// assert_eq!((3..=5).into_inner(), (3, 5)); |
| /// ``` |
| #[stable(feature = "inclusive_range_methods", since = "1.27.0")] |
| #[inline] |
| pub fn into_inner(self) -> (Idx, Idx) { |
| (self.start, self.end) |
| } |
| } |
| |
| #[stable(feature = "inclusive_range", since = "1.26.0")] |
| impl<Idx: fmt::Debug> fmt::Debug for RangeInclusive<Idx> { |
| fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { |
| self.start.fmt(fmt)?; |
| write!(fmt, "..=")?; |
| self.end.fmt(fmt)?; |
| if self.exhausted { |
| write!(fmt, " (exhausted)")?; |
| } |
| Ok(()) |
| } |
| } |
| |
| impl<Idx: PartialOrd<Idx>> RangeInclusive<Idx> { |
| /// Returns `true` if `item` is contained in the range. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// assert!(!(3..=5).contains(&2)); |
| /// assert!( (3..=5).contains(&3)); |
| /// assert!( (3..=5).contains(&4)); |
| /// assert!( (3..=5).contains(&5)); |
| /// assert!(!(3..=5).contains(&6)); |
| /// |
| /// assert!( (3..=3).contains(&3)); |
| /// assert!(!(3..=2).contains(&3)); |
| /// |
| /// assert!( (0.0..=1.0).contains(&1.0)); |
| /// assert!(!(0.0..=1.0).contains(&f32::NAN)); |
| /// assert!(!(0.0..=f32::NAN).contains(&0.0)); |
| /// assert!(!(f32::NAN..=1.0).contains(&1.0)); |
| /// ``` |
| #[stable(feature = "range_contains", since = "1.35.0")] |
| pub fn contains<U>(&self, item: &U) -> bool |
| where |
| Idx: PartialOrd<U>, |
| U: ?Sized + PartialOrd<Idx>, |
| { |
| <Self as RangeBounds<Idx>>::contains(self, item) |
| } |
| |
| /// Returns `true` if the range contains no items. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// assert!(!(3..=5).is_empty()); |
| /// assert!(!(3..=3).is_empty()); |
| /// assert!( (3..=2).is_empty()); |
| /// ``` |
| /// |
| /// The range is empty if either side is incomparable: |
| /// |
| /// ``` |
| /// assert!(!(3.0..=5.0).is_empty()); |
| /// assert!( (3.0..=f32::NAN).is_empty()); |
| /// assert!( (f32::NAN..=5.0).is_empty()); |
| /// ``` |
| /// |
| /// This method returns `true` after iteration has finished: |
| /// |
| /// ``` |
| /// let mut r = 3..=5; |
| /// for _ in r.by_ref() {} |
| /// // Precise field values are unspecified here |
| /// assert!(r.is_empty()); |
| /// ``` |
| #[stable(feature = "range_is_empty", since = "1.47.0")] |
| #[inline] |
| pub fn is_empty(&self) -> bool { |
| self.exhausted || !(self.start <= self.end) |
| } |
| } |
| |
| /// A range only bounded inclusively above (`..=end`). |
| /// |
| /// The `RangeToInclusive` `..=end` contains all values with `x <= end`. |
| /// It cannot serve as an [`Iterator`] because it doesn't have a starting point. |
| /// |
| /// # Examples |
| /// |
| /// The `..=end` syntax is a `RangeToInclusive`: |
| /// |
| /// ``` |
| /// assert_eq!((..=5), std::ops::RangeToInclusive{ end: 5 }); |
| /// ``` |
| /// |
| /// It does not have an [`IntoIterator`] implementation, so you can't use it in a |
| /// `for` loop directly. This won't compile: |
| /// |
| /// ```compile_fail,E0277 |
| /// // error[E0277]: the trait bound `std::ops::RangeToInclusive<{integer}>: |
| /// // std::iter::Iterator` is not satisfied |
| /// for i in ..=5 { |
| /// // ... |
| /// } |
| /// ``` |
| /// |
| /// When used as a [slicing index], `RangeToInclusive` produces a slice of all |
| /// array elements up to and including the index indicated by `end`. |
| /// |
| /// ``` |
| /// let arr = [0, 1, 2, 3, 4]; |
| /// assert_eq!(arr[ .. ], [0, 1, 2, 3, 4]); |
| /// assert_eq!(arr[ .. 3], [0, 1, 2 ]); |
| /// assert_eq!(arr[ ..=3], [0, 1, 2, 3 ]); // This is a `RangeToInclusive` |
| /// assert_eq!(arr[1.. ], [ 1, 2, 3, 4]); |
| /// assert_eq!(arr[1.. 3], [ 1, 2 ]); |
| /// assert_eq!(arr[1..=3], [ 1, 2, 3 ]); |
| /// ``` |
| /// |
| /// [slicing index]: crate::slice::SliceIndex |
| #[lang = "RangeToInclusive"] |
| #[doc(alias = "..=")] |
| #[derive(Copy, Clone, PartialEq, Eq, Hash)] |
| #[stable(feature = "inclusive_range", since = "1.26.0")] |
| pub struct RangeToInclusive<Idx> { |
| /// The upper bound of the range (inclusive) |
| #[stable(feature = "inclusive_range", since = "1.26.0")] |
| pub end: Idx, |
| } |
| |
| #[stable(feature = "inclusive_range", since = "1.26.0")] |
| impl<Idx: fmt::Debug> fmt::Debug for RangeToInclusive<Idx> { |
| fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { |
| write!(fmt, "..=")?; |
| self.end.fmt(fmt)?; |
| Ok(()) |
| } |
| } |
| |
| impl<Idx: PartialOrd<Idx>> RangeToInclusive<Idx> { |
| /// Returns `true` if `item` is contained in the range. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// assert!( (..=5).contains(&-1_000_000_000)); |
| /// assert!( (..=5).contains(&5)); |
| /// assert!(!(..=5).contains(&6)); |
| /// |
| /// assert!( (..=1.0).contains(&1.0)); |
| /// assert!(!(..=1.0).contains(&f32::NAN)); |
| /// assert!(!(..=f32::NAN).contains(&0.5)); |
| /// ``` |
| #[stable(feature = "range_contains", since = "1.35.0")] |
| pub fn contains<U>(&self, item: &U) -> bool |
| where |
| Idx: PartialOrd<U>, |
| U: ?Sized + PartialOrd<Idx>, |
| { |
| <Self as RangeBounds<Idx>>::contains(self, item) |
| } |
| } |
| |
| // RangeToInclusive<Idx> cannot impl From<RangeTo<Idx>> |
| // because underflow would be possible with (..0).into() |
| |
| /// An endpoint of a range of keys. |
| /// |
| /// # Examples |
| /// |
| /// `Bound`s are range endpoints: |
| /// |
| /// ``` |
| /// use std::ops::Bound::*; |
| /// use std::ops::RangeBounds; |
| /// |
| /// assert_eq!((..100).start_bound(), Unbounded); |
| /// assert_eq!((1..12).start_bound(), Included(&1)); |
| /// assert_eq!((1..12).end_bound(), Excluded(&12)); |
| /// ``` |
| /// |
| /// Using a tuple of `Bound`s as an argument to [`BTreeMap::range`]. |
| /// Note that in most cases, it's better to use range syntax (`1..5`) instead. |
| /// |
| /// ``` |
| /// use std::collections::BTreeMap; |
| /// use std::ops::Bound::{Excluded, Included, Unbounded}; |
| /// |
| /// let mut map = BTreeMap::new(); |
| /// map.insert(3, "a"); |
| /// map.insert(5, "b"); |
| /// map.insert(8, "c"); |
| /// |
| /// for (key, value) in map.range((Excluded(3), Included(8))) { |
| /// println!("{}: {}", key, value); |
| /// } |
| /// |
| /// assert_eq!(Some((&3, &"a")), map.range((Unbounded, Included(5))).next()); |
| /// ``` |
| /// |
| /// [`BTreeMap::range`]: ../../std/collections/btree_map/struct.BTreeMap.html#method.range |
| #[stable(feature = "collections_bound", since = "1.17.0")] |
| #[derive(Clone, Copy, Debug, Hash, PartialEq, Eq)] |
| pub enum Bound<T> { |
| /// An inclusive bound. |
| #[stable(feature = "collections_bound", since = "1.17.0")] |
| Included(#[stable(feature = "collections_bound", since = "1.17.0")] T), |
| /// An exclusive bound. |
| #[stable(feature = "collections_bound", since = "1.17.0")] |
| Excluded(#[stable(feature = "collections_bound", since = "1.17.0")] T), |
| /// An infinite endpoint. Indicates that there is no bound in this direction. |
| #[stable(feature = "collections_bound", since = "1.17.0")] |
| Unbounded, |
| } |
| |
| impl<T: Clone> Bound<&T> { |
| /// Map a `Bound<&T>` to a `Bound<T>` by cloning the contents of the bound. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// #![feature(bound_cloned)] |
| /// use std::ops::Bound::*; |
| /// use std::ops::RangeBounds; |
| /// |
| /// assert_eq!((1..12).start_bound(), Included(&1)); |
| /// assert_eq!((1..12).start_bound().cloned(), Included(1)); |
| /// ``` |
| #[unstable(feature = "bound_cloned", issue = "61356")] |
| pub fn cloned(self) -> Bound<T> { |
| match self { |
| Bound::Unbounded => Bound::Unbounded, |
| Bound::Included(x) => Bound::Included(x.clone()), |
| Bound::Excluded(x) => Bound::Excluded(x.clone()), |
| } |
| } |
| } |
| |
| /// `RangeBounds` is implemented by Rust's built-in range types, produced |
| /// by range syntax like `..`, `a..`, `..b`, `..=c`, `d..e`, or `f..=g`. |
| #[stable(feature = "collections_range", since = "1.28.0")] |
| pub trait RangeBounds<T: ?Sized> { |
| /// Start index bound. |
| /// |
| /// Returns the start value as a `Bound`. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// # fn main() { |
| /// use std::ops::Bound::*; |
| /// use std::ops::RangeBounds; |
| /// |
| /// assert_eq!((..10).start_bound(), Unbounded); |
| /// assert_eq!((3..10).start_bound(), Included(&3)); |
| /// # } |
| /// ``` |
| #[stable(feature = "collections_range", since = "1.28.0")] |
| fn start_bound(&self) -> Bound<&T>; |
| |
| /// End index bound. |
| /// |
| /// Returns the end value as a `Bound`. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// # fn main() { |
| /// use std::ops::Bound::*; |
| /// use std::ops::RangeBounds; |
| /// |
| /// assert_eq!((3..).end_bound(), Unbounded); |
| /// assert_eq!((3..10).end_bound(), Excluded(&10)); |
| /// # } |
| /// ``` |
| #[stable(feature = "collections_range", since = "1.28.0")] |
| fn end_bound(&self) -> Bound<&T>; |
| |
| /// Performs bounds-checking of this range. |
| /// |
| /// The returned [`Range`] is safe to pass to [`slice::get_unchecked`] and |
| /// [`slice::get_unchecked_mut`] for slices of the given length. |
| /// |
| /// [`slice::get_unchecked`]: ../../std/primitive.slice.html#method.get_unchecked |
| /// [`slice::get_unchecked_mut`]: ../../std/primitive.slice.html#method.get_unchecked_mut |
| /// |
| /// # Panics |
| /// |
| /// Panics if the range would be out of bounds. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// #![feature(range_bounds_assert_len)] |
| /// |
| /// use std::ops::RangeBounds; |
| /// |
| /// let v = [10, 40, 30]; |
| /// assert_eq!(1..2, (1..2).assert_len(v.len())); |
| /// assert_eq!(0..2, (..2).assert_len(v.len())); |
| /// assert_eq!(1..3, (1..).assert_len(v.len())); |
| /// ``` |
| /// |
| /// Panics when [`Index::index`] would panic: |
| /// |
| /// ```should_panic |
| /// #![feature(range_bounds_assert_len)] |
| /// |
| /// use std::ops::RangeBounds; |
| /// |
| /// (2..1).assert_len(3); |
| /// ``` |
| /// |
| /// ```should_panic |
| /// #![feature(range_bounds_assert_len)] |
| /// |
| /// use std::ops::RangeBounds; |
| /// |
| /// (1..4).assert_len(3); |
| /// ``` |
| /// |
| /// ```should_panic |
| /// #![feature(range_bounds_assert_len)] |
| /// |
| /// use std::ops::RangeBounds; |
| /// |
| /// (1..=usize::MAX).assert_len(3); |
| /// ``` |
| /// |
| /// [`Index::index`]: crate::ops::Index::index |
| #[track_caller] |
| #[unstable(feature = "range_bounds_assert_len", issue = "76393")] |
| fn assert_len(self, len: usize) -> Range<usize> |
| where |
| Self: RangeBounds<usize>, |
| { |
| let start: Bound<&usize> = self.start_bound(); |
| let start = match start { |
| Bound::Included(&start) => start, |
| Bound::Excluded(start) => { |
| start.checked_add(1).unwrap_or_else(|| slice_start_index_overflow_fail()) |
| } |
| Bound::Unbounded => 0, |
| }; |
| |
| let end: Bound<&usize> = self.end_bound(); |
| let end = match end { |
| Bound::Included(end) => { |
| end.checked_add(1).unwrap_or_else(|| slice_end_index_overflow_fail()) |
| } |
| Bound::Excluded(&end) => end, |
| Bound::Unbounded => len, |
| }; |
| |
| if start > end { |
| slice_index_order_fail(start, end); |
| } |
| if end > len { |
| slice_end_index_len_fail(end, len); |
| } |
| |
| Range { start, end } |
| } |
| |
| /// Returns `true` if `item` is contained in the range. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// assert!( (3..5).contains(&4)); |
| /// assert!(!(3..5).contains(&2)); |
| /// |
| /// assert!( (0.0..1.0).contains(&0.5)); |
| /// assert!(!(0.0..1.0).contains(&f32::NAN)); |
| /// assert!(!(0.0..f32::NAN).contains(&0.5)); |
| /// assert!(!(f32::NAN..1.0).contains(&0.5)); |
| #[stable(feature = "range_contains", since = "1.35.0")] |
| fn contains<U>(&self, item: &U) -> bool |
| where |
| T: PartialOrd<U>, |
| U: ?Sized + PartialOrd<T>, |
| { |
| (match self.start_bound() { |
| Included(ref start) => *start <= item, |
| Excluded(ref start) => *start < item, |
| Unbounded => true, |
| }) && (match self.end_bound() { |
| Included(ref end) => item <= *end, |
| Excluded(ref end) => item < *end, |
| Unbounded => true, |
| }) |
| } |
| } |
| |
| use self::Bound::{Excluded, Included, Unbounded}; |
| |
| #[stable(feature = "collections_range", since = "1.28.0")] |
| impl<T: ?Sized> RangeBounds<T> for RangeFull { |
| fn start_bound(&self) -> Bound<&T> { |
| Unbounded |
| } |
| fn end_bound(&self) -> Bound<&T> { |
| Unbounded |
| } |
| } |
| |
| #[stable(feature = "collections_range", since = "1.28.0")] |
| impl<T> RangeBounds<T> for RangeFrom<T> { |
| fn start_bound(&self) -> Bound<&T> { |
| Included(&self.start) |
| } |
| fn end_bound(&self) -> Bound<&T> { |
| Unbounded |
| } |
| } |
| |
| #[stable(feature = "collections_range", since = "1.28.0")] |
| impl<T> RangeBounds<T> for RangeTo<T> { |
| fn start_bound(&self) -> Bound<&T> { |
| Unbounded |
| } |
| fn end_bound(&self) -> Bound<&T> { |
| Excluded(&self.end) |
| } |
| } |
| |
| #[stable(feature = "collections_range", since = "1.28.0")] |
| impl<T> RangeBounds<T> for Range<T> { |
| fn start_bound(&self) -> Bound<&T> { |
| Included(&self.start) |
| } |
| fn end_bound(&self) -> Bound<&T> { |
| Excluded(&self.end) |
| } |
| } |
| |
| #[stable(feature = "collections_range", since = "1.28.0")] |
| impl<T> RangeBounds<T> for RangeInclusive<T> { |
| fn start_bound(&self) -> Bound<&T> { |
| Included(&self.start) |
| } |
| fn end_bound(&self) -> Bound<&T> { |
| Included(&self.end) |
| } |
| } |
| |
| #[stable(feature = "collections_range", since = "1.28.0")] |
| impl<T> RangeBounds<T> for RangeToInclusive<T> { |
| fn start_bound(&self) -> Bound<&T> { |
| Unbounded |
| } |
| fn end_bound(&self) -> Bound<&T> { |
| Included(&self.end) |
| } |
| } |
| |
| #[stable(feature = "collections_range", since = "1.28.0")] |
| impl<T> RangeBounds<T> for (Bound<T>, Bound<T>) { |
| fn start_bound(&self) -> Bound<&T> { |
| match *self { |
| (Included(ref start), _) => Included(start), |
| (Excluded(ref start), _) => Excluded(start), |
| (Unbounded, _) => Unbounded, |
| } |
| } |
| |
| fn end_bound(&self) -> Bound<&T> { |
| match *self { |
| (_, Included(ref end)) => Included(end), |
| (_, Excluded(ref end)) => Excluded(end), |
| (_, Unbounded) => Unbounded, |
| } |
| } |
| } |
| |
| #[stable(feature = "collections_range", since = "1.28.0")] |
| impl<'a, T: ?Sized + 'a> RangeBounds<T> for (Bound<&'a T>, Bound<&'a T>) { |
| fn start_bound(&self) -> Bound<&T> { |
| self.0 |
| } |
| |
| fn end_bound(&self) -> Bound<&T> { |
| self.1 |
| } |
| } |
| |
| #[stable(feature = "collections_range", since = "1.28.0")] |
| impl<T> RangeBounds<T> for RangeFrom<&T> { |
| fn start_bound(&self) -> Bound<&T> { |
| Included(self.start) |
| } |
| fn end_bound(&self) -> Bound<&T> { |
| Unbounded |
| } |
| } |
| |
| #[stable(feature = "collections_range", since = "1.28.0")] |
| impl<T> RangeBounds<T> for RangeTo<&T> { |
| fn start_bound(&self) -> Bound<&T> { |
| Unbounded |
| } |
| fn end_bound(&self) -> Bound<&T> { |
| Excluded(self.end) |
| } |
| } |
| |
| #[stable(feature = "collections_range", since = "1.28.0")] |
| impl<T> RangeBounds<T> for Range<&T> { |
| fn start_bound(&self) -> Bound<&T> { |
| Included(self.start) |
| } |
| fn end_bound(&self) -> Bound<&T> { |
| Excluded(self.end) |
| } |
| } |
| |
| #[stable(feature = "collections_range", since = "1.28.0")] |
| impl<T> RangeBounds<T> for RangeInclusive<&T> { |
| fn start_bound(&self) -> Bound<&T> { |
| Included(self.start) |
| } |
| fn end_bound(&self) -> Bound<&T> { |
| Included(self.end) |
| } |
| } |
| |
| #[stable(feature = "collections_range", since = "1.28.0")] |
| impl<T> RangeBounds<T> for RangeToInclusive<&T> { |
| fn start_bound(&self) -> Bound<&T> { |
| Unbounded |
| } |
| fn end_bound(&self) -> Bound<&T> { |
| Included(self.end) |
| } |
| } |