From 6ea2d1afcb89d3414312521a63a591d34ae5f8dd Mon Sep 17 00:00:00 2001
From: Wesley Norris <repnop@outlook.com>
Date: Thu, 23 Jan 2020 17:58:27 -0500
Subject: [PATCH 1/2] Add From<&[T]> and From<&mut [T]> for TinyVec

This adds the From trait impls for `&[T]` and `&mut [T]` to `TinyVec`,
though unfortunately until we get lazy normalization, it currently
requires that the `A: Array<item = T>` bound also be `Default`, so
it does not work for array sizes > 32.
---
 src/tinyvec.rs | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/src/tinyvec.rs b/src/tinyvec.rs
index ab4e5e4..c28e3ad 100644
--- a/src/tinyvec.rs
+++ b/src/tinyvec.rs
@@ -665,6 +665,37 @@ impl<A: Array> From<ArrayVec<A>> for TinyVec<A> {
   }
 }
 
+impl<T, A> From<&'_ [T]> for TinyVec<A>
+where
+  T: Clone + Default,
+  A: Array<Item = T> + Default,
+{
+  #[inline]
+  #[must_use]
+  fn from(slice: &[T]) -> Self {
+    if slice.len() > A::CAPACITY {
+      TinyVec::Heap(slice.into())
+    } else {
+      let mut arr = ArrayVec::new();
+      arr.extend_from_slice(slice);
+
+      TinyVec::Inline(arr)
+    }
+  }
+}
+
+impl<T, A> From<&'_ mut [T]> for TinyVec<A>
+where
+  T: Clone + Default,
+  A: Array<Item = T> + Default,
+{
+  #[inline]
+  #[must_use]
+  fn from(slice: &mut [T]) -> Self {
+    Self::from(&*slice)
+  }
+}
+
 impl<A: Array + Default> FromIterator<A::Item> for TinyVec<A> {
   #[inline]
   #[must_use]

From 48905d9c43c1d71185199c5e6368eab1c668a827 Mon Sep 17 00:00:00 2001
From: Wesley Norris <repnop@outlook.com>
Date: Fri, 24 Jan 2020 08:24:44 -0500
Subject: [PATCH 2/2] Add TinyVec::from(slice) test

---
 tests/tinyvec.rs | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/tests/tinyvec.rs b/tests/tinyvec.rs
index 705ab59..617193a 100644
--- a/tests/tinyvec.rs
+++ b/tests/tinyvec.rs
@@ -65,3 +65,22 @@ fn TinyVec_resize() {
   tv.resize(20, 5);
   assert_eq!(&tv[..], &[5; 20]);
 }
+
+#[test]
+fn TinyVec_from_slice_impl() {
+  let bigger_slice: [u8; 11] = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
+  let tinyvec: TinyVec<[u8; 10]> = TinyVec::Heap((&bigger_slice[..]).into());
+  assert_eq!(TinyVec::from(&bigger_slice[..]), tinyvec);
+
+  let smaller_slice: [u8; 5] = [0, 1, 2, 3, 4];
+  let tinyvec: TinyVec<[u8; 10]> = TinyVec::Inline(ArrayVec::from_array_len(
+    [0, 1, 2, 3, 4, 0, 0, 0, 0, 0],
+    5,
+  ));
+  assert_eq!(TinyVec::from(&smaller_slice[..]), tinyvec);
+
+  let same_size: [u8; 4] = [0, 1, 2, 3];
+  let tinyvec: TinyVec<[u8; 4]> =
+    TinyVec::Inline(ArrayVec::from_array_len(same_size, 4));
+  assert_eq!(TinyVec::from(&same_size[..]), tinyvec);
+}