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improve doc tests for (min/max/minmax).* functions
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- add tests for `a == b` where missing
- try to make all the tests more similar
- try to use more illustrative test values
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@WaffleLapkin
WaffleLapkin committed Jan 31, 2025
1 parent 99768c8 commit b20307b
Showing 1 changed file with 128 additions and 18 deletions.
146 changes: 128 additions & 18 deletions library/core/src/cmp.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -973,6 +973,24 @@ pub trait Ord: Eq + PartialOrd<Self> {
/// assert_eq!(1.max(2), 2);
/// assert_eq!(2.max(2), 2);
/// ```
/// ```
/// use std::cmp::Ordering;
///
/// #[derive(Eq)]
/// struct Equal(&'static str);
///
/// impl PartialEq for Equal {
/// fn eq(&self, other: &Self) -> bool { true }
/// }
/// impl PartialOrd for Equal {
/// fn partial_cmp(&self, other: &Self) -> Option<Ordering> { Some(Ordering::Equal) }
/// }
/// impl Ord for Equal {
/// fn cmp(&self, other: &Self) -> Ordering { Ordering::Equal }
/// }
///
/// assert_eq!(Equal("self").max(Equal("other")).0, "other");
/// ```
#[stable(feature = "ord_max_min", since = "1.21.0")]
#[inline]
#[must_use]
Expand All @@ -994,6 +1012,24 @@ pub trait Ord: Eq + PartialOrd<Self> {
/// assert_eq!(1.min(2), 1);
/// assert_eq!(2.min(2), 2);
/// ```
/// ```
/// use std::cmp::Ordering;
///
/// #[derive(Eq)]
/// struct Equal(&'static str);
///
/// impl PartialEq for Equal {
/// fn eq(&self, other: &Self) -> bool { true }
/// }
/// impl PartialOrd for Equal {
/// fn partial_cmp(&self, other: &Self) -> Option<Ordering> { Some(Ordering::Equal) }
/// }
/// impl Ord for Equal {
/// fn cmp(&self, other: &Self) -> Ordering { Ordering::Equal }
/// }
///
/// assert_eq!(Equal("self").min(Equal("other")).0, "self");
/// ```
#[stable(feature = "ord_max_min", since = "1.21.0")]
#[inline]
#[must_use]
Expand Down Expand Up @@ -1414,6 +1450,24 @@ pub macro PartialOrd($item:item) {
/// assert_eq!(cmp::min(1, 2), 1);
/// assert_eq!(cmp::min(2, 2), 2);
/// ```
/// ```
/// use std::cmp::{self, Ordering};
///
/// #[derive(Eq)]
/// struct Equal(&'static str);
///
/// impl PartialEq for Equal {
/// fn eq(&self, other: &Self) -> bool { true }
/// }
/// impl PartialOrd for Equal {
/// fn partial_cmp(&self, other: &Self) -> Option<Ordering> { Some(Ordering::Equal) }
/// }
/// impl Ord for Equal {
/// fn cmp(&self, other: &Self) -> Ordering { Ordering::Equal }
/// }
///
/// assert_eq!(cmp::min(Equal("v1"), Equal("v2")).0, "v1");
/// ```
#[inline]
#[must_use]
#[stable(feature = "rust1", since = "1.0.0")]
Expand All @@ -1431,11 +1485,16 @@ pub fn min<T: Ord>(v1: T, v2: T) -> T {
/// ```
/// use std::cmp;
///
/// let result = cmp::min_by(-2, 1, |x: &i32, y: &i32| x.abs().cmp(&y.abs()));
/// assert_eq!(result, 1);
/// let abs_cmp = |x: &i32, y: &i32| x.abs().cmp(&y.abs());
///
/// let result = cmp::min_by(-2, 3, |x: &i32, y: &i32| x.abs().cmp(&y.abs()));
/// assert_eq!(result, -2);
/// let result = cmp::min_by(2, -1, abs_cmp);
/// assert_eq!(result, -1);
///
/// let result = cmp::min_by(2, -3, abs_cmp);
/// assert_eq!(result, 2);
///
/// let result = cmp::min_by(1, -1, abs_cmp);
/// assert_eq!(result, 1);
/// ```
#[inline]
#[must_use]
Expand All @@ -1456,11 +1515,14 @@ pub fn min_by<T, F: FnOnce(&T, &T) -> Ordering>(v1: T, v2: T, compare: F) -> T {
/// ```
/// use std::cmp;
///
/// let result = cmp::min_by_key(-2, 1, |x: &i32| x.abs());
/// assert_eq!(result, 1);
/// let result = cmp::min_by_key(2, -1, |x: &i32| x.abs());
/// assert_eq!(result, -1);
///
/// let result = cmp::min_by_key(-2, 2, |x: &i32| x.abs());
/// assert_eq!(result, -2);
/// let result = cmp::min_by_key(2, -3, |x: &i32| x.abs());
/// assert_eq!(result, 2);
///
/// let result = cmp::min_by_key(1, -1, |x: &i32| x.abs());
/// assert_eq!(result, 1);
/// ```
#[inline]
#[must_use]
Expand All @@ -1483,6 +1545,24 @@ pub fn min_by_key<T, F: FnMut(&T) -> K, K: Ord>(v1: T, v2: T, mut f: F) -> T {
/// assert_eq!(cmp::max(1, 2), 2);
/// assert_eq!(cmp::max(2, 2), 2);
/// ```
/// ```
/// use std::cmp::{self, Ordering};
///
/// #[derive(Eq)]
/// struct Equal(&'static str);
///
/// impl PartialEq for Equal {
/// fn eq(&self, other: &Self) -> bool { true }
/// }
/// impl PartialOrd for Equal {
/// fn partial_cmp(&self, other: &Self) -> Option<Ordering> { Some(Ordering::Equal) }
/// }
/// impl Ord for Equal {
/// fn cmp(&self, other: &Self) -> Ordering { Ordering::Equal }
/// }
///
/// assert_eq!(cmp::max(Equal("v1"), Equal("v2")).0, "v2");
/// ```
#[inline]
#[must_use]
#[stable(feature = "rust1", since = "1.0.0")]
Expand All @@ -1500,11 +1580,16 @@ pub fn max<T: Ord>(v1: T, v2: T) -> T {
/// ```
/// use std::cmp;
///
/// let result = cmp::max_by(-2, 1, |x: &i32, y: &i32| x.abs().cmp(&y.abs()));
/// let abs_cmp = |x: &i32, y: &i32| x.abs().cmp(&y.abs());
///
/// let result = cmp::max_by(3, -2, abs_cmp) ;
/// assert_eq!(result, 3);
///
/// let result = cmp::max_by(1, -2, abs_cmp);
/// assert_eq!(result, -2);
///
/// let result = cmp::max_by(-2, 2, |x: &i32, y: &i32| x.abs().cmp(&y.abs())) ;
/// assert_eq!(result, 2);
/// let result = cmp::max_by(1, -1, abs_cmp);
/// assert_eq!(result, -1);
/// ```
#[inline]
#[must_use]
Expand All @@ -1525,11 +1610,14 @@ pub fn max_by<T, F: FnOnce(&T, &T) -> Ordering>(v1: T, v2: T, compare: F) -> T {
/// ```
/// use std::cmp;
///
/// let result = cmp::max_by_key(-2, 1, |x: &i32| x.abs());
/// let result = cmp::max_by_key(3, -2, |x: &i32| x.abs());
/// assert_eq!(result, 3);
///
/// let result = cmp::max_by_key(1, -2, |x: &i32| x.abs());
/// assert_eq!(result, -2);
///
/// let result = cmp::max_by_key(-2, 2, |x: &i32| x.abs());
/// assert_eq!(result, 2);
/// let result = cmp::max_by_key(1, -1, |x: &i32| x.abs());
/// assert_eq!(result, -1);
/// ```
#[inline]
#[must_use]
Expand All @@ -1549,13 +1637,32 @@ pub fn max_by_key<T, F: FnMut(&T) -> K, K: Ord>(v1: T, v2: T, mut f: F) -> T {
/// use std::cmp;
///
/// assert_eq!(cmp::minmax(1, 2), [1, 2]);
/// assert_eq!(cmp::minmax(2, 2), [2, 2]);
/// assert_eq!(cmp::minmax(2, 1), [1, 2]);
///
/// // You can destructure the result using array patterns
/// let [min, max] = cmp::minmax(42, 17);
/// assert_eq!(min, 17);
/// assert_eq!(max, 42);
/// ```
/// ```
/// #![feature(cmp_minmax)]
/// use std::cmp::{self, Ordering};
///
/// #[derive(Eq)]
/// struct Equal(&'static str);
///
/// impl PartialEq for Equal {
/// fn eq(&self, other: &Self) -> bool { true }
/// }
/// impl PartialOrd for Equal {
/// fn partial_cmp(&self, other: &Self) -> Option<Ordering> { Some(Ordering::Equal) }
/// }
/// impl Ord for Equal {
/// fn cmp(&self, other: &Self) -> Ordering { Ordering::Equal }
/// }
///
/// assert_eq!(cmp::minmax(Equal("v1"), Equal("v2")).map(|v| v.0), ["v1", "v2"]);
/// ```
#[inline]
#[must_use]
#[unstable(feature = "cmp_minmax", issue = "115939")]
Expand All @@ -1576,11 +1683,14 @@ where
/// #![feature(cmp_minmax)]
/// use std::cmp;
///
/// assert_eq!(cmp::minmax_by(-2, 1, |x: &i32, y: &i32| x.abs().cmp(&y.abs())), [1, -2]);
/// assert_eq!(cmp::minmax_by(-2, 2, |x: &i32, y: &i32| x.abs().cmp(&y.abs())), [-2, 2]);
/// let abs_cmp = |x: &i32, y: &i32| x.abs().cmp(&y.abs());
///
/// assert_eq!(cmp::minmax_by(-2, 1, abs_cmp), [1, -2]);
/// assert_eq!(cmp::minmax_by(-1, 2, abs_cmp), [-1, 2]);
/// assert_eq!(cmp::minmax_by(-2, 2, abs_cmp), [-2, 2]);
///
/// // You can destructure the result using array patterns
/// let [min, max] = cmp::minmax_by(-42, 17, |x: &i32, y: &i32| x.abs().cmp(&y.abs()));
/// let [min, max] = cmp::minmax_by(-42, 17, abs_cmp);
/// assert_eq!(min, 17);
/// assert_eq!(max, -42);
/// ```
Expand Down

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