From ef24de24a82fe681581cc130f342363c47c0969a Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 7 Jun 2024 07:48:48 +0200 Subject: Merging upstream version 1.75.0+dfsg1. Signed-off-by: Daniel Baumann --- vendor/itertools-0.10.5/src/size_hint.rs | 119 +++++++++++++++++++++++++++++++ 1 file changed, 119 insertions(+) create mode 100644 vendor/itertools-0.10.5/src/size_hint.rs (limited to 'vendor/itertools-0.10.5/src/size_hint.rs') diff --git a/vendor/itertools-0.10.5/src/size_hint.rs b/vendor/itertools-0.10.5/src/size_hint.rs new file mode 100644 index 000000000..71ea1412b --- /dev/null +++ b/vendor/itertools-0.10.5/src/size_hint.rs @@ -0,0 +1,119 @@ +//! Arithmetic on `Iterator.size_hint()` values. +//! + +use std::usize; +use std::cmp; +use std::u32; + +/// `SizeHint` is the return type of `Iterator::size_hint()`. +pub type SizeHint = (usize, Option); + +/// Add `SizeHint` correctly. +#[inline] +pub fn add(a: SizeHint, b: SizeHint) -> SizeHint { + let min = a.0.saturating_add(b.0); + let max = match (a.1, b.1) { + (Some(x), Some(y)) => x.checked_add(y), + _ => None, + }; + + (min, max) +} + +/// Add `x` correctly to a `SizeHint`. +#[inline] +pub fn add_scalar(sh: SizeHint, x: usize) -> SizeHint { + let (mut low, mut hi) = sh; + low = low.saturating_add(x); + hi = hi.and_then(|elt| elt.checked_add(x)); + (low, hi) +} + +/// Subtract `x` correctly from a `SizeHint`. +#[inline] +#[allow(dead_code)] +pub fn sub_scalar(sh: SizeHint, x: usize) -> SizeHint { + let (mut low, mut hi) = sh; + low = low.saturating_sub(x); + hi = hi.map(|elt| elt.saturating_sub(x)); + (low, hi) +} + + +/// Multiply `SizeHint` correctly +/// +/// ```ignore +/// use std::usize; +/// use itertools::size_hint; +/// +/// assert_eq!(size_hint::mul((3, Some(4)), (3, Some(4))), +/// (9, Some(16))); +/// +/// assert_eq!(size_hint::mul((3, Some(4)), (usize::MAX, None)), +/// (usize::MAX, None)); +/// +/// assert_eq!(size_hint::mul((3, None), (0, Some(0))), +/// (0, Some(0))); +/// ``` +#[inline] +pub fn mul(a: SizeHint, b: SizeHint) -> SizeHint { + let low = a.0.saturating_mul(b.0); + let hi = match (a.1, b.1) { + (Some(x), Some(y)) => x.checked_mul(y), + (Some(0), None) | (None, Some(0)) => Some(0), + _ => None, + }; + (low, hi) +} + +/// Multiply `x` correctly with a `SizeHint`. +#[inline] +pub fn mul_scalar(sh: SizeHint, x: usize) -> SizeHint { + let (mut low, mut hi) = sh; + low = low.saturating_mul(x); + hi = hi.and_then(|elt| elt.checked_mul(x)); + (low, hi) +} + +/// Raise `base` correctly by a `SizeHint` exponent. +#[inline] +pub fn pow_scalar_base(base: usize, exp: SizeHint) -> SizeHint { + let exp_low = cmp::min(exp.0, u32::MAX as usize) as u32; + let low = base.saturating_pow(exp_low); + + let hi = exp.1.and_then(|exp| { + let exp_hi = cmp::min(exp, u32::MAX as usize) as u32; + base.checked_pow(exp_hi) + }); + + (low, hi) +} + +/// Return the maximum +#[inline] +pub fn max(a: SizeHint, b: SizeHint) -> SizeHint { + let (a_lower, a_upper) = a; + let (b_lower, b_upper) = b; + + let lower = cmp::max(a_lower, b_lower); + + let upper = match (a_upper, b_upper) { + (Some(x), Some(y)) => Some(cmp::max(x, y)), + _ => None, + }; + + (lower, upper) +} + +/// Return the minimum +#[inline] +pub fn min(a: SizeHint, b: SizeHint) -> SizeHint { + let (a_lower, a_upper) = a; + let (b_lower, b_upper) = b; + let lower = cmp::min(a_lower, b_lower); + let upper = match (a_upper, b_upper) { + (Some(u1), Some(u2)) => Some(cmp::min(u1, u2)), + _ => a_upper.or(b_upper), + }; + (lower, upper) +} -- cgit v1.2.3