Auto merge of #69570 - Dylan-DPC:rollup-d6boczt, r=Dylan-DPC

Rollup of 6 pull requests

Successful merges:

 - #69477 (docs: add mention of async blocks in move keyword docs)
 - #69504 (Use assert_ne in hash tests)
 - #69546 (use to_vec() instead of .iter().cloned().collect() to convert slices to vecs.)
 - #69551 (use is_empty() instead of len() == x  to determine if structs are empty.)
 - #69563 (Fix no_std detection for target triples)
 - #69567 (use .to_string() instead of format!() macro to create strings)

Failed merges:

r? @ghost

Author: bors

src/bootstrap/config.rs

@@ -180,7 +180,7 @@ pub struct Target {
 impl Target {
     pub fn from_triple(triple: &str) -> Self {
         let mut target: Self = Default::default();
-        if triple.contains("-none-") || triple.contains("nvptx") {
+        if triple.contains("-none") || triple.contains("nvptx") {
             target.no_std = true;
         }
         target

src/libcore/slice/mod.rs

@@ -3823,7 +3823,7 @@ where
         // The last index of self.v is already checked and found to match
         // by the last iteration, so we start searching a new match
         // one index to the left.
-        let remainder = if self.v.len() == 0 { &[] } else { &self.v[..(self.v.len() - 1)] };
+        let remainder = if self.v.is_empty() { &[] } else { &self.v[..(self.v.len() - 1)] };
         let idx = remainder.iter().rposition(|x| (self.pred)(x)).map(|idx| idx + 1).unwrap_or(0);
         if idx == 0 {
             self.finished = true;
@@ -4033,7 +4033,7 @@ where
             return None;
         }
 
-        let idx_opt = if self.v.len() == 0 {
+        let idx_opt = if self.v.is_empty() {
             None
         } else {
             // work around borrowck limitations

src/libcore/tests/hash/sip.rs

@@ -238,7 +238,7 @@ fn test_siphash_2_4() {
 #[cfg(target_pointer_width = "32")]
 fn test_hash_usize() {
     let val = 0xdeadbeef_deadbeef_u64;
-    assert!(hash(&(val as u64)) != hash(&(val as usize)));
+    assert_ne!(hash(&(val as u64)), hash(&(val as usize)));
     assert_eq!(hash(&(val as u32)), hash(&(val as usize)));
 }
 
@@ -247,7 +247,7 @@ fn test_hash_usize() {
 fn test_hash_usize() {
     let val = 0xdeadbeef_deadbeef_u64;
     assert_eq!(hash(&(val as u64)), hash(&(val as usize)));
-    assert!(hash(&(val as u32)) != hash(&(val as usize)));
+    assert_ne!(hash(&(val as u32)), hash(&(val as usize)));
 }
 
 #[test]
@@ -262,14 +262,14 @@ fn test_hash_idempotent() {
 fn test_hash_no_bytes_dropped_64() {
     let val = 0xdeadbeef_deadbeef_u64;
 
-    assert!(hash(&val) != hash(&zero_byte(val, 0)));
-    assert!(hash(&val) != hash(&zero_byte(val, 1)));
-    assert!(hash(&val) != hash(&zero_byte(val, 2)));
-    assert!(hash(&val) != hash(&zero_byte(val, 3)));
-    assert!(hash(&val) != hash(&zero_byte(val, 4)));
-    assert!(hash(&val) != hash(&zero_byte(val, 5)));
-    assert!(hash(&val) != hash(&zero_byte(val, 6)));
-    assert!(hash(&val) != hash(&zero_byte(val, 7)));
+    assert_ne!(hash(&val), hash(&zero_byte(val, 0)));
+    assert_ne!(hash(&val), hash(&zero_byte(val, 1)));
+    assert_ne!(hash(&val), hash(&zero_byte(val, 2)));
+    assert_ne!(hash(&val), hash(&zero_byte(val, 3)));
+    assert_ne!(hash(&val), hash(&zero_byte(val, 4)));
+    assert_ne!(hash(&val), hash(&zero_byte(val, 5)));
+    assert_ne!(hash(&val), hash(&zero_byte(val, 6)));
+    assert_ne!(hash(&val), hash(&zero_byte(val, 7)));
 
     fn zero_byte(val: u64, byte: usize) -> u64 {
         assert!(byte < 8);
@@ -281,10 +281,10 @@ fn test_hash_no_bytes_dropped_64() {
 fn test_hash_no_bytes_dropped_32() {
     let val = 0xdeadbeef_u32;
 
-    assert!(hash(&val) != hash(&zero_byte(val, 0)));
-    assert!(hash(&val) != hash(&zero_byte(val, 1)));
-    assert!(hash(&val) != hash(&zero_byte(val, 2)));
-    assert!(hash(&val) != hash(&zero_byte(val, 3)));
+    assert_ne!(hash(&val), hash(&zero_byte(val, 0)));
+    assert_ne!(hash(&val), hash(&zero_byte(val, 1)));
+    assert_ne!(hash(&val), hash(&zero_byte(val, 2)));
+    assert_ne!(hash(&val), hash(&zero_byte(val, 3)));
 
     fn zero_byte(val: u32, byte: usize) -> u32 {
         assert!(byte < 4);
@@ -299,14 +299,17 @@ fn test_hash_no_concat_alias() {
     let u = ("a", "abb");
 
     assert!(s != t && t != u);
-    assert!(hash(&s) != hash(&t) && hash(&s) != hash(&u));
+    assert_ne!(s, t);
+    assert_ne!(t, u);
+    assert_ne!(hash(&s), hash(&t));
+    assert_ne!(hash(&s), hash(&u));
 
     let u = [1, 0, 0, 0];
     let v = (&u[..1], &u[1..3], &u[3..]);
     let w = (&u[..], &u[4..4], &u[4..4]);
 
-    assert!(v != w);
-    assert!(hash(&v) != hash(&w));
+    assert_ne!(v, w);
+    assert_ne!(hash(&v), hash(&w));
 }
 
 #[test]

src/librustc/arena.rs

@@ -250,7 +250,7 @@ impl<'tcx> Arena<'tcx> {
 
     #[inline]
     pub fn alloc_slice<T: Copy>(&self, value: &[T]) -> &mut [T] {
-        if value.len() == 0 {
+        if value.is_empty() {
             return &mut [];
         }
         self.dropless.alloc_slice(value)

src/librustc/dep_graph/graph.rs

@@ -809,7 +809,7 @@ impl DepGraph {
             dep_node
         );
 
-        if unlikely!(diagnostics.len() > 0) {
+        if unlikely!(!diagnostics.is_empty()) {
             self.emit_diagnostics(tcx, data, dep_node_index, prev_dep_node_index, diagnostics);
         }
 

src/librustc/ich/hcx.rs

@@ -19,7 +19,7 @@ use smallvec::SmallVec;
 use std::cmp::Ord;
 
 fn compute_ignored_attr_names() -> FxHashSet<Symbol> {
-    debug_assert!(ich::IGNORED_ATTRIBUTES.len() > 0);
+    debug_assert!(!ich::IGNORED_ATTRIBUTES.is_empty());
     ich::IGNORED_ATTRIBUTES.iter().map(|&s| s).collect()
 }
 

src/librustc/ich/impls_syntax.rs

@@ -14,7 +14,7 @@ impl<'ctx> rustc_target::HashStableContext for StableHashingContext<'ctx> {}
 
 impl<'a> HashStable<StableHashingContext<'a>> for [ast::Attribute] {
     fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
-        if self.len() == 0 {
+        if self.is_empty() {
             self.len().hash_stable(hcx, hasher);
             return;
         }

src/librustc/mir/interpret/error.rs

@@ -171,7 +171,7 @@ impl<'tcx> ConstEvalErr<'tcx> {
             // Skip the last, which is just the environment of the constant.  The stacktrace
             // is sometimes empty because we create "fake" eval contexts in CTFE to do work
             // on constant values.
-            if self.stacktrace.len() > 0 {
+            if !self.stacktrace.is_empty() {
                 for frame_info in &self.stacktrace[..self.stacktrace.len() - 1] {
                     err.span_label(frame_info.call_site, frame_info.to_string());
                 }

src/librustc/mir/mod.rs

@@ -2219,7 +2219,7 @@ impl<'tcx> Debug for Rvalue<'tcx> {
                 });
                 let region = if print_region {
                     let mut region = region.to_string();
-                    if region.len() > 0 {
+                    if !region.is_empty() {
                         region.push(' ');
                     }
                     region

src/librustc/query/mod.rs

@@ -18,7 +18,7 @@ use std::borrow::Cow;
 
 fn describe_as_module(def_id: DefId, tcx: TyCtxt<'_>) -> String {
     if def_id.is_top_level_module() {
-        format!("top-level module")
+        "top-level module".to_string()
     } else {
         format!("module `{}`", tcx.def_path_str(def_id))
     }