Use const_unwrap for char::from_u32_unchecked

Author: ChrisDenton

library/core/src/char/convert.rs

@@ -23,7 +23,7 @@ pub(super) const fn from_u32(i: u32) -> Option<char> {
 #[must_use]
 pub(super) const unsafe fn from_u32_unchecked(i: u32) -> char {
     // SAFETY: the caller must guarantee that `i` is a valid char value.
-    if cfg!(debug_assertions) { char::from_u32(i).unwrap() } else { unsafe { transmute(i) } }
+    if cfg!(debug_assertions) { char::from_u32(i).const_unwrap() } else { unsafe { transmute(i) } }
 }
 
 #[stable(feature = "char_convert", since = "1.13.0")]

library/core/src/option.rs

@@ -1811,6 +1811,18 @@ impl<T> Option<T> {
         }
     }
 }
+impl<T: Copy> Option<T> {
+    /// Unwrap `Copy` types in a const context. Other than the `Copy` bounds,
+    /// this is the same as [`unwrap`][Option::unwrap].
+    #[inline]
+    #[track_caller]
+    pub(crate) const fn const_unwrap(self) -> T {
+        match self {
+            Some(val) => val,
+            None => panic("called `Option::unwrap()` on a `None` value"),
+        }
+    }
+}
 
 impl<T, U> Option<(T, U)> {
     /// Unzips an option containing a tuple of two options.