Implement From<[T; N]> for BinaryHeap<T>

Port rust-lang/rust PR's implementing `From<[T; N]>` for
`BinaryHeap<T>`:

- #84111: "Stabilize `impl From<[(K, V); N]> for HashMap` (and friends)"
- #88611: "Deprecate array::IntoIter::new."

NOTE: This requires Rust 1.56.0 or greater.

Author: clint-white

build.rs

@@ -7,7 +7,7 @@ fn main() {
     // Required for stabilization of `unsafe_op_in_unsafe_fn` lint.
     ac.emit_rustc_version(1, 52);
 
-    // Required for stabilization of `Vec::shrink_to()`.
+    // Required for stabilization of `Vec::shrink_to()` and `IntoIterator` for arrays.
     ac.emit_rustc_version(1, 56);
 
     autocfg::rerun_path("build.rs");

src/binary_heap.rs

@@ -1666,6 +1666,25 @@ impl<T: Ord> From<Vec<T>> for BinaryHeap<T> {
     }
 }
 
+/// # Compatibility
+///
+/// This trait is only implemented for Rust 1.56.0 or greater.
+#[cfg(rustc_1_56)]
+impl<T: Ord, const N: usize> From<[T; N]> for BinaryHeap<T> {
+    /// ```
+    /// use binary_heap_plus::BinaryHeap;
+    ///
+    /// let mut h1 = BinaryHeap::from([1, 4, 2, 3]);
+    /// let mut h2: BinaryHeap<_> = [1, 4, 2, 3].into();
+    /// while let Some((a, b)) = h1.pop().zip(h2.pop()) {
+    ///     assert_eq!(a, b);
+    /// }
+    /// ```
+    fn from(arr: [T; N]) -> Self {
+        Self::from_iter(arr)
+    }
+}
+
 /// # Compatibility
 ///
 /// This trait is only implemented for Rust 1.41.0 or greater.  For earlier versions, `Into<Vec<T>>`