Merge pull request #314 from rust-lang/try-from-slice

impl TryFrom<&[T]> for Simd

Author: calebzulawski

crates/core_simd/src/vector.rs

@@ -650,6 +650,30 @@ where
     }
 }
 
+impl<T, const LANES: usize> TryFrom<&[T]> for Simd<T, LANES>
+where
+    LaneCount<LANES>: SupportedLaneCount,
+    T: SimdElement,
+{
+    type Error = core::array::TryFromSliceError;
+
+    fn try_from(slice: &[T]) -> Result<Self, Self::Error> {
+        Ok(Self::from_array(slice.try_into()?))
+    }
+}
+
+impl<T, const LANES: usize> TryFrom<&mut [T]> for Simd<T, LANES>
+where
+    LaneCount<LANES>: SupportedLaneCount,
+    T: SimdElement,
+{
+    type Error = core::array::TryFromSliceError;
+
+    fn try_from(slice: &mut [T]) -> Result<Self, Self::Error> {
+        Ok(Self::from_array(slice.try_into()?))
+    }
+}
+
 mod sealed {
     pub trait Sealed {}
 }

crates/core_simd/tests/try_from_slice.rs

@@ -0,0 +1,25 @@
+#![feature(portable_simd)]
+
+#[cfg(target_arch = "wasm32")]
+use wasm_bindgen_test::*;
+
+#[cfg(target_arch = "wasm32")]
+wasm_bindgen_test_configure!(run_in_browser);
+
+use core_simd::i32x4;
+
+#[test]
+#[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+fn try_from_slice() {
+    // Equal length
+    assert_eq!(
+        i32x4::try_from([1, 2, 3, 4].as_slice()).unwrap(),
+        i32x4::from_array([1, 2, 3, 4])
+    );
+
+    // Slice length > vector length
+    assert!(i32x4::try_from([1, 2, 3, 4, 5].as_slice()).is_err());
+
+    // Slice length < vector length
+    assert!(i32x4::try_from([1, 2, 3].as_slice()).is_err());
+}