Rollup merge of rust-lang#50574 - s3bk:range_inclusive_into_inner, r=SimonSapin

add fn `into_inner(self) -> (Idx, Idx)` to RangeInclusive (rust-lang#49022)

adds `into_inner(self) -> (Idx, Idx)` to RangeInclusive
rust-lang#49022 (comment)

Author: alexcrichton

src/libcore/ops/range.rs

@@ -411,6 +411,21 @@ impl<Idx> RangeInclusive<Idx> {
     pub fn end(&self) -> &Idx {
         &self.end
     }
+
+    /// Destructures the RangeInclusive into (lower bound, upper (inclusive) bound).
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(inclusive_range_methods)]
+    ///
+    /// assert_eq!((3..=5).into_inner(), (3, 5));
+    /// ```
+    #[unstable(feature = "inclusive_range_methods", issue = "49022")]
+    #[inline]
+    pub fn into_inner(self) -> (Idx, Idx) {
+        (self.start, self.end)
+    }
 }
 
 #[stable(feature = "inclusive_range", since = "1.26.0")]