Auto merge of #102192 - matthiaskrgr:rollup-0ctjzco, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - #102094 (Add missing documentation for `bool::from_str`)
 - #102115 (Add examples to `bool::then` and `bool::then_some`)
 - #102134 (Detect panic strategy using `rustc --print cfg`)
 - #102137 (Don't convert valtree to constvalue during normalization)
 - #102148 (add regression test for miri issue 2433)
 - #102158 (rustdoc: clean up CSS/DOM for deprecation warnings)
 - #102177 (Fix a typo in `std`'s root docs)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

compiler/rustc_trait_selection/src/traits/query/normalize.rs

@@ -351,25 +351,7 @@ impl<'cx, 'tcx> FallibleTypeFolder<'tcx> for QueryNormalizer<'cx, 'tcx> {
         &mut self,
         constant: mir::ConstantKind<'tcx>,
     ) -> Result<mir::ConstantKind<'tcx>, Self::Error> {
-        Ok(match constant {
-            mir::ConstantKind::Ty(c) => {
-                let const_folded = c.try_super_fold_with(self)?;
-                match const_folded.kind() {
-                    ty::ConstKind::Value(valtree) => {
-                        let tcx = self.infcx.tcx;
-                        let ty = const_folded.ty();
-                        let const_val = tcx.valtree_to_const_val((ty, valtree));
-                        debug!(?ty, ?valtree, ?const_val);
-
-                        mir::ConstantKind::Val(const_val, ty)
-                    }
-                    _ => mir::ConstantKind::Ty(const_folded),
-                }
-            }
-            mir::ConstantKind::Val(_, _) | mir::ConstantKind::Unevaluated(..) => {
-                constant.try_super_fold_with(self)?
-            }
-        })
+        constant.try_super_fold_with(self)
     }
 
     #[inline]

library/core/src/bool.rs

@@ -18,6 +18,18 @@ impl bool {
     /// assert_eq!(false.then_some(0), None);
     /// assert_eq!(true.then_some(0), Some(0));
     /// ```
+    ///
+    /// ```
+    /// let mut a = 0;
+    /// let mut function_with_side_effects = || { a += 1; };
+    ///
+    /// true.then_some(function_with_side_effects());
+    /// false.then_some(function_with_side_effects());
+    ///
+    /// // `a` is incremented twice because the value passed to `then_some` is
+    /// // evaluated eagerly.
+    /// assert_eq!(a, 2);
+    /// ```
     #[stable(feature = "bool_to_option", since = "1.62.0")]
     #[rustc_const_unstable(feature = "const_bool_to_option", issue = "91917")]
     #[inline]
@@ -37,6 +49,17 @@ impl bool {
     /// assert_eq!(false.then(|| 0), None);
     /// assert_eq!(true.then(|| 0), Some(0));
     /// ```
+    ///
+    /// ```
+    /// let mut a = 0;
+    ///
+    /// true.then(|| { a += 1; });
+    /// false.then(|| { a += 1; });
+    ///
+    /// // `a` is incremented once because the closure is evaluated lazily by
+    /// // `then`.
+    /// assert_eq!(a, 1);
+    /// ```
     #[stable(feature = "lazy_bool_to_option", since = "1.50.0")]
     #[rustc_const_unstable(feature = "const_bool_to_option", issue = "91917")]
     #[inline]