New upstream version 1.69.0+dfsg1

[rustc.git] / library / core / src / ops / try_trait.rs

diff --git a/library/core/src/ops/try_trait.rs b/library/core/src/ops/try_trait.rs
index 84a69046807c4b3fb314afd6b96ed46e0dcf7bc4..86aa1e4fd20ba48ce698ca58edcfe40daebb187b 100644 (file)
--- a/library/core/src/ops/try_trait.rs
+++ b/library/core/src/ops/try_trait.rs
@@ -379,13 +379,27 @@ pub(crate) type ChangeOutputType<T, V> = <<T as Try>::Residual as Residual<V>>::
 pub(crate) struct NeverShortCircuit<T>(pub T);
 
 impl<T> NeverShortCircuit<T> {
-    /// Implementation for building `ConstFnMutClosure` for wrapping the output of a ~const FnMut in a `NeverShortCircuit`.
+    /// Wraps a unary function to produce one that wraps the output into a `NeverShortCircuit`.
+    ///
+    /// This is useful for implementing infallible functions in terms of the `try_` ones,
+    /// without accidentally capturing extra generic parameters in a closure.
+    #[inline]
+    pub fn wrap_mut_1<A>(mut f: impl FnMut(A) -> T) -> impl FnMut(A) -> NeverShortCircuit<T> {
+        move |a| NeverShortCircuit(f(a))
+    }
+
     #[inline]
-    pub const fn wrap_mut_2_imp<A, B, F: ~const FnMut(A, B) -> T>(
-        f: &mut F,
-        (a, b): (A, B),
-    ) -> NeverShortCircuit<T> {
-        NeverShortCircuit(f(a, b))
+    pub fn wrap_mut_2<A, B>(
+        mut f: impl ~const FnMut(A, B) -> T,
+    ) -> impl ~const FnMut(A, B) -> Self {
+        cfg_if! {
+            if #[cfg(bootstrap)] {
+                #[allow(unused_parens)]
+                (const move |a, b| NeverShortCircuit(f(a, b)))
+            } else {
+                const move |a, b| NeverShortCircuit(f(a, b))
+            }
+        }
     }
 }