hybrid-array: add slice_as_chunks(_mut) methods, minor refactoring (#974)

Author: newpavlov

hybrid-array/src/impls.rs

@@ -0,0 +1,146 @@
+use super::{Array, ArrayOps, ArraySize, IntoArray};
+
+macro_rules! impl_array_size {
+    ($($len:expr => $ty:ident),+) => {
+        $(
+            impl<T> ArrayOps<T, $len> for Array<T, typenum::$ty> {
+                const SIZE: usize = $len;
+                type Size = typenum::$ty;
+
+                #[inline]
+                fn as_core_array(&self) -> &[T; $len] {
+                    &self.0
+                }
+
+                #[inline]
+                fn as_mut_core_array(&mut self) -> &mut [T; $len] {
+                    &mut self.0
+                }
+
+                #[inline]
+                fn from_core_array(arr: [T; $len]) -> Self {
+                    Self(arr)
+                }
+
+                #[inline]
+                fn ref_from_core_array(array_ref: &[T; $len]) -> &Self {
+                    // SAFETY: `Self` is a `repr(transparent)` newtype for `[T; $len]`
+                    unsafe { &*(array_ref.as_ptr() as *const Self) }
+                }
+
+                #[inline]
+                fn ref_from_mut_core_array(array_ref: &mut [T; $len]) -> &mut Self {
+                    // SAFETY: `Self` is a `repr(transparent)` newtype for `[T; $len]`
+                    unsafe { &mut *(array_ref.as_mut_ptr() as *mut Self) }
+                }
+
+                #[inline]
+                fn map_to_core_array<F, U>(self, f: F) -> [U; $len]
+                where
+                    F: FnMut(T) -> U
+                {
+                    self.0.map(f)
+                }
+            }
+
+            unsafe impl ArraySize for typenum::$ty {
+                type ArrayType<T> = [T; $len];
+            }
+
+            impl<T> From<Array<T, typenum::$ty>> for [T; $len] {
+                fn from(arr: Array<T, typenum::$ty>) -> [T; $len] {
+                    arr.0
+                }
+            }
+
+            impl<T> IntoArray<T> for [T; $len] {
+                type Size = typenum::$ty;
+
+                fn into_hybrid_array(self) -> Array<T, Self::Size> {
+                    Array::from_core_array(self)
+                }
+            }
+        )+
+     };
+}
+
+impl_array_size! {
+    0 => U0,
+    1 => U1,
+    2 => U2,
+    3 => U3,
+    4 => U4,
+    5 => U5,
+    6 => U6,
+    7 => U7,
+    8 => U8,
+    9 => U9,
+    10 => U10,
+    11 => U11,
+    12 => U12,
+    13 => U13,
+    14 => U14,
+    15 => U15,
+    16 => U16,
+    17 => U17,
+    18 => U18,
+    19 => U19,
+    20 => U20,
+    21 => U21,
+    22 => U22,
+    23 => U23,
+    24 => U24,
+    25 => U25,
+    26 => U26,
+    27 => U27,
+    28 => U28,
+    29 => U29,
+    30 => U30,
+    31 => U31,
+    32 => U32,
+    33 => U33,
+    34 => U34,
+    35 => U35,
+    36 => U36,
+    37 => U37,
+    38 => U38,
+    39 => U39,
+    40 => U40,
+    41 => U41,
+    42 => U42,
+    43 => U43,
+    44 => U44,
+    45 => U45,
+    46 => U46,
+    47 => U47,
+    48 => U48,
+    49 => U49,
+    50 => U50,
+    51 => U51,
+    52 => U52,
+    53 => U53,
+    54 => U54,
+    55 => U55,
+    56 => U56,
+    57 => U57,
+    58 => U58,
+    59 => U59,
+    60 => U60,
+    61 => U61,
+    62 => U62,
+    63 => U63,
+    64 => U64,
+    96 => U96,
+    128 => U128,
+    192 => U192,
+    256 => U256,
+    384 => U384,
+    448 => U448,
+    512 => U512,
+    768 => U768,
+    896 => U896,
+    1024 => U1024,
+    2048 => U2048,
+    4096 => U4096,
+    8192 => U8192
+}