Rollup merge of #103176 - nnethercote:fix-TyKind-is_simple_path, r=spastorino

Fix `TyKind::is_simple_path`

Fixes #103157.

r? `@spastorino`

compiler/rustc_ast/src/ast.rs

@@ -2060,8 +2060,11 @@ pub fn is_unit(&self) -> bool {
     }
 
     pub fn is_simple_path(&self) -> Option<Symbol> {
-        if let TyKind::Path(None, Path { segments, .. }) = &self && segments.len() == 1 {
-            Some(segments[0].ident.name)
+        if let TyKind::Path(None, Path { segments, .. }) = &self
+            && let [segment] = &segments[..]
+            && segment.args.is_none()
+        {
+            Some(segment.ident.name)
         } else {
             None
         }

src/test/ui/deriving/deriving-all-codegen.rs

@@ -85,7 +85,7 @@ enum Mixed {
     P,
     Q,
     R(u32),
-    S { d1: u32, d2: u32 },
+    S { d1: Option<u32>, d2: Option<i32> },
 }
 
 // An enum with no fieldless variants. Note that `Default` cannot be derived

src/test/ui/deriving/deriving-all-codegen.stdout

@@ -809,8 +809,8 @@ enum Mixed {
     Q,
     R(u32),
     S {
-        d1: u32,
-        d2: u32,
+        d1: Option<u32>,
+        d2: Option<i32>,
     },
 }
 #[automatically_derived]
@@ -818,6 +818,8 @@ impl ::core::clone::Clone for Mixed {
     #[inline]
     fn clone(&self) -> Mixed {
         let _: ::core::clone::AssertParamIsClone<u32>;
+        let _: ::core::clone::AssertParamIsClone<Option<u32>>;
+        let _: ::core::clone::AssertParamIsClone<Option<i32>>;
         *self
     }
 }
@@ -886,6 +888,8 @@ impl ::core::cmp::Eq for Mixed {
     #[no_coverage]
     fn assert_receiver_is_total_eq(&self) -> () {
         let _: ::core::cmp::AssertParamIsEq<u32>;
+        let _: ::core::cmp::AssertParamIsEq<Option<u32>>;
+        let _: ::core::cmp::AssertParamIsEq<Option<i32>>;
     }
 }
 #[automatically_derived]

src/test/ui/deriving/issue-103157.rs

@@ -0,0 +1,12 @@
+// check-fail
+
+#[derive(PartialEq, Eq)]
+pub enum Value {
+    Boolean(Option<bool>),
+    Float(Option<f64>), //~ ERROR the trait bound `f64: Eq` is not satisfied
+}
+
+fn main() {
+    let a = Value::Float(Some(f64::NAN));
+    assert!(a == a);
+}

src/test/ui/deriving/issue-103157.stderr

@@ -0,0 +1,30 @@
+error[E0277]: the trait bound `f64: Eq` is not satisfied
+  --> $DIR/issue-103157.rs:6:11
+   |
+LL | #[derive(PartialEq, Eq)]
+   |                     -- in this derive macro expansion
+...
+LL |     Float(Option<f64>),
+   |           ^^^^^^^^^^^ the trait `Eq` is not implemented for `f64`
+   |
+   = help: the following other types implement trait `Eq`:
+             i128
+             i16
+             i32
+             i64
+             i8
+             isize
+             u128
+             u16
+           and 4 others
+   = note: required for `Option<f64>` to implement `Eq`
+note: required by a bound in `AssertParamIsEq`
+  --> $SRC_DIR/core/src/cmp.rs:LL:COL
+   |
+LL | pub struct AssertParamIsEq<T: Eq + ?Sized> {
+   |                               ^^ required by this bound in `AssertParamIsEq`
+   = note: this error originates in the derive macro `Eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.