Rollup merge of rust-lang#126249 - workingjubilee:simplify-try-map-signature, r=scottmcm

workingjubilee · web-flow · commit 439c2ae36dc0 · 2024-06-12T03:57:21.000-07:00
Simplify `[T; N]::try_map` signature

People keep making fun of this signature for being so gnarly.
Associated type bounds admit a much simpler scribbling.

r? ````@scottmcm````
diff --git a/core/src/array/mod.rs b/core/src/array/mod.rs
@@ -533,11 +533,9 @@ impl<T, const N: usize> [T; N] {
     /// assert_eq!(c, Some(a));
     /// ```
     #[unstable(feature = "array_try_map", issue = "79711")]
-    pub fn try_map<F, R>(self, f: F) -> ChangeOutputType<R, [R::Output; N]>
+    pub fn try_map<R>(self, f: impl FnMut(T) -> R) -> ChangeOutputType<R, [R::Output; N]>
     where
-        F: FnMut(T) -> R,
-        R: Try,
-        R::Residual: Residual<[R::Output; N]>,
+        R: Try<Residual: Residual<[R::Output; N]>>,
     {
         drain_array_with(self, |iter| try_from_trusted_iterator(iter.map(f)))
     }
diff --git a/core/src/ops/try_trait.rs b/core/src/ops/try_trait.rs
@@ -363,7 +363,9 @@ pub trait Residual<O> {
 }
 
 #[unstable(feature = "pub_crate_should_not_need_unstable_attr", issue = "none")]
-pub(crate) type ChangeOutputType<T, V> = <<T as Try>::Residual as Residual<V>>::TryType;
+#[allow(type_alias_bounds)]
+pub(crate) type ChangeOutputType<T: Try<Residual: Residual<V>>, V> =
+    <T::Residual as Residual<V>>::TryType;
 
 /// An adapter for implementing non-try methods via the `Try` implementation.
 ///

Original file line number	Diff line number	Diff line change
`@@ -533,11 +533,9 @@ impl<T, const N: usize> [T; N] {`
`533`	`533`	`/// assert_eq!(c, Some(a));`
`534`	`534`	/// ```
`535`	`535`	`#[unstable(feature = "array_try_map", issue = "79711")]`
`536`		`- pub fn try_map<F, R>(self, f: F) -> ChangeOutputType<R, [R::Output; N]>`
	`536`	`+ pub fn try_map<R>(self, f: impl FnMut(T) -> R) -> ChangeOutputType<R, [R::Output; N]>`
`537`	`537`	`where`
`538`		`- F: FnMut(T) -> R,`
`539`		`- R: Try,`
`540`		`- R::Residual: Residual<[R::Output; N]>,`
	`538`	`+ R: Try<Residual: Residual<[R::Output; N]>>,`
`541`	`539`	`{`
`542`	`540`	`drain_array_with(self, \|iter\| try_from_trusted_iterator(iter.map(f)))`
`543`	`541`	`}`
Original file line number	Diff line number	Diff line change
`@@ -363,7 +363,9 @@ pub trait Residual<O> {`
`363`	`363`	`}`
`364`	`364`
`365`	`365`	`#[unstable(feature = "pub_crate_should_not_need_unstable_attr", issue = "none")]`
`366`		`-pub(crate) type ChangeOutputType<T, V> = <<T as Try>::Residual as Residual<V>>::TryType;`
	`366`	`+#[allow(type_alias_bounds)]`
	`367`	`+pub(crate) type ChangeOutputType<T: Try<Residual: Residual<V>>, V> =`
	`368`	`+ <T::Residual as Residual<V>>::TryType;`
`367`	`369`
`368`	`370`	/// An adapter for implementing non-try methods via the `Try` implementation.
`369`	`371`	`///`