Rollup merge of #61048 - wizAmit:feature/nth_back_chunks, r=scottmcm

[rust.git] / src / libcore / tests / slice.rs

diff --git a/src/libcore/tests/slice.rs b/src/libcore/tests/slice.rs
index 007283b5f69c874201ce6bf3bd10626c4f3663e2..9710f019f4e4df0ba630cfd6c4a0c0e6bd246345 100644 (file)
--- a/src/libcore/tests/slice.rs
+++ b/src/libcore/tests/slice.rs
@@ -134,6 +134,30 @@ fn test_chunks_nth() {
     assert_eq!(c2.next(), None);
 }
 
+#[test]
+fn test_chunks_nth_back() {
+    let v: &[i32] = &[0, 1, 2, 3, 4, 5];
+    let mut c = v.chunks(2);
+    assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
+    assert_eq!(c.next().unwrap(), &[0, 1]);
+    assert_eq!(c.next(), None);
+
+    let v2: &[i32] = &[0, 1, 2, 3, 4];
+    let mut c2 = v2.chunks(3);
+    assert_eq!(c2.nth_back(1).unwrap(), &[0, 1, 2]);
+    assert_eq!(c2.next(), None);
+    assert_eq!(c2.next_back(), None);
+
+    let v3: &[i32] = &[0, 1, 2, 3, 4];
+    let mut c3 = v3.chunks(10);
+    assert_eq!(c3.nth_back(0).unwrap(), &[0, 1, 2, 3, 4]);
+    assert_eq!(c3.next(), None);
+
+    let v4: &[i32] = &[0, 1, 2];
+    let mut c4 = v4.chunks(10);
+    assert_eq!(c4.nth_back(1_000_000_000usize), None);
+}
+
 #[test]
 fn test_chunks_last() {
     let v: &[i32] = &[0, 1, 2, 3, 4, 5];
@@ -356,6 +380,19 @@ fn test_rchunks_nth() {
     assert_eq!(c2.next(), None);
 }
 
+#[test]
+fn test_rchunks_nth_back() {
+    let v: &[i32] = &[0, 1, 2, 3, 4, 5];
+    let mut c = v.rchunks(2);
+    assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
+    assert_eq!(c.next_back().unwrap(), &[4, 5]);
+
+    let v2: &[i32] = &[0, 1, 2, 3, 4];
+    let mut c2 = v2.rchunks(3);
+    assert_eq!(c2.nth_back(1).unwrap(), &[2, 3, 4]);
+    assert_eq!(c2.next_back(), None);
+}
+
 #[test]
 fn test_rchunks_last() {
     let v: &[i32] = &[0, 1, 2, 3, 4, 5];
@@ -407,6 +444,19 @@ fn test_rchunks_mut_nth() {
     assert_eq!(c2.next(), None);
 }
 
+#[test]
+fn test_rchunks_mut_nth_back() {
+    let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
+    let mut c = v.rchunks_mut(2);
+    assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
+    assert_eq!(c.next_back().unwrap(), &[4, 5]);
+
+    let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
+    let mut c2 = v2.rchunks_mut(3);
+    assert_eq!(c2.nth_back(1).unwrap(), &[2, 3, 4]);
+    assert_eq!(c2.next_back(), None);
+}
+
 #[test]
 fn test_rchunks_mut_last() {
     let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
@@ -460,6 +510,19 @@ fn test_rchunks_exact_nth() {
     assert_eq!(c2.next(), None);
 }
 
+#[test]
+fn test_rchunks_exact_nth_back() {
+    let v: &[i32] = &[0, 1, 2, 3, 4, 5];
+    let mut c = v.rchunks_exact(2);
+    assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
+    assert_eq!(c.next_back().unwrap(), &[4, 5]);
+
+    let v2: &[i32] = &[0, 1, 2, 3, 4, 5, 6];
+    let mut c2 = v2.rchunks_exact(3);
+    assert_eq!(c2.nth_back(1).unwrap(), &[4, 5, 6]);
+    assert_eq!(c2.next(), None);
+}
+
 #[test]
 fn test_rchunks_exact_last() {
     let v: &[i32] = &[0, 1, 2, 3, 4, 5];
@@ -518,6 +581,19 @@ fn test_rchunks_exact_mut_nth() {
     assert_eq!(c2.next(), None);
 }
 
+#[test]
+fn test_rchunks_exact_mut_nth_back() {
+    let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
+    let mut c = v.rchunks_exact_mut(2);
+    assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
+    assert_eq!(c.next_back().unwrap(), &[4, 5]);
+
+    let v2: &mut [i32] = &mut [0, 1, 2, 3, 4, 5, 6];
+    let mut c2 = v2.rchunks_exact_mut(3);
+    assert_eq!(c2.nth_back(1).unwrap(), &[4, 5, 6]);
+    assert_eq!(c2.next(), None);
+}
+
 #[test]
 fn test_rchunks_exact_mut_last() {
     let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
@@ -1024,22 +1100,31 @@ fn test_rotate_right() {
 
 #[test]
 #[cfg(not(target_arch = "wasm32"))]
-#[cfg(not(miri))] // Miri does not support entropy
 fn sort_unstable() {
     use core::cmp::Ordering::{Equal, Greater, Less};
     use core::slice::heapsort;
     use rand::{FromEntropy, Rng, rngs::SmallRng, seq::SliceRandom};
 
+    #[cfg(not(miri))] // Miri is too slow
+    let large_range = 500..510;
+    #[cfg(not(miri))] // Miri is too slow
+    let rounds = 100;
+
+    #[cfg(miri)]
+    let large_range = 0..0; // empty range
+    #[cfg(miri)]
+    let rounds = 1;
+
     let mut v = [0; 600];
     let mut tmp = [0; 600];
     let mut rng = SmallRng::from_entropy();
 
-    for len in (2..25).chain(500..510) {
+    for len in (2..25).chain(large_range) {
         let v = &mut v[0..len];
         let tmp = &mut tmp[0..len];
 
         for &modulus in &[5, 10, 100, 1000] {
-            for _ in 0..100 {
+            for _ in 0..rounds {
                 for i in 0..len {
                     v[i] = rng.gen::<i32>() % modulus;
                 }
@@ -1095,7 +1180,7 @@ fn sort_unstable() {
 
 #[test]
 #[cfg(not(target_arch = "wasm32"))]
-#[cfg(not(miri))] // Miri does not support entropy
+#[cfg(not(miri))] // Miri is too slow
 fn partition_at_index() {
     use core::cmp::Ordering::{Equal, Greater, Less};
     use rand::rngs::SmallRng;