Remove duplication in from_shape_ptr and split_at

Author: jturner314

src/impl_raw_views.rs

@@ -1,4 +1,4 @@
-use dimension;
+use dimension::{self, stride_offset};
 use imp_prelude::*;
 use {is_aligned, StrideShape};
 
@@ -87,6 +87,33 @@ where
     pub unsafe fn deref_into_view<'a>(self) -> ArrayView<'a, A, D> {
         ArrayView::new_(self.ptr, self.dim, self.strides)
     }
+
+    /// Split the array view along `axis` and return one array pointer strictly
+    /// before the split and one array pointer after the split.
+    ///
+    /// **Panics** if `axis` or `index` is out of bounds.
+    pub fn split_at(self, axis: Axis, index: Ix) -> (Self, Self) {
+        assert!(index <= self.len_of(axis));
+        let left_ptr = self.ptr;
+        let right_ptr = if index == self.len_of(axis) {
+            self.ptr
+        } else {
+            let offset = stride_offset(index, self.strides.axis(axis));
+            // The `.offset()` is safe due to the guarantees of `DataRaw`.
+            unsafe { self.ptr.offset(offset) }
+        };
+
+        let mut dim_left = self.dim.clone();
+        dim_left.set_axis(axis, index);
+        let left = unsafe { Self::new_(left_ptr, dim_left, self.strides.clone()) };
+
+        let mut dim_right = self.dim;
+        let right_len = dim_right.axis(axis) - index;
+        dim_right.set_axis(axis, right_len);
+        let right = unsafe { Self::new_(right_ptr, dim_right, self.strides) };
+
+        (left, right)
+    }
 }
 
 impl<A, D> RawArrayViewMut<A, D>
@@ -155,6 +182,12 @@ where
         RawArrayViewMut::new_(ptr, dim, strides)
     }
 
+    /// Converts to a non-mutable `RawArrayView`.
+    #[inline]
+    pub(crate) fn into_raw_view(self) -> RawArrayView<A, D> {
+        unsafe { RawArrayView::new_(self.ptr, self.dim, self.strides) }
+    }
+
     /// Return a read-only view of the array
     ///
     /// **Warning** from a safety standpoint, this is equivalent to
@@ -194,4 +227,18 @@ where
     pub unsafe fn deref_into_view_mut<'a>(self) -> ArrayViewMut<'a, A, D> {
         ArrayViewMut::new_(self.ptr, self.dim, self.strides)
     }
+
+    /// Split the array view along `axis` and return one array pointer strictly
+    /// before the split and one array pointer after the split.
+    ///
+    /// **Panics** if `axis` or `index` is out of bounds.
+    pub fn split_at(self, axis: Axis, index: Ix) -> (Self, Self) {
+        let (left, right) = self.into_raw_view().split_at(axis, index);
+        unsafe {
+            (
+                Self::new_(left.ptr, left.dim, left.strides),
+                Self::new_(right.ptr, right.dim, right.strides),
+            )
+        }
+    }
 }

src/impl_views.rs

@@ -9,7 +9,7 @@
 use std::slice;
 
 use imp_prelude::*;
-use dimension::{self, stride_offset};
+use dimension;
 use error::ShapeError;
 use arraytraits::array_out_of_bounds;
 use {is_aligned, NdIndex, StrideShape};
@@ -111,15 +111,7 @@ impl<'a, A, D> ArrayView<'a, A, D>
     pub unsafe fn from_shape_ptr<Sh>(shape: Sh, ptr: *const A) -> Self
         where Sh: Into<StrideShape<D>>
     {
-        let shape = shape.into();
-        let dim = shape.dim;
-        let strides = shape.strides;
-        if cfg!(debug_assertions) {
-            assert!(!ptr.is_null(), "The pointer must be non-null.");
-            assert!(is_aligned(ptr), "The pointer must be aligned.");
-            dimension::max_abs_offset_check_overflow::<A, _>(&dim, &strides).unwrap();
-        }
-        ArrayView::new_(ptr, dim, strides)
+        RawArrayView::from_shape_ptr(shape, ptr).deref_into_view()
     }
 
     /// Convert the view into an `ArrayView<'b, A, D>` where `'b` is a lifetime
@@ -141,35 +133,11 @@ impl<'a, A, D> ArrayView<'a, A, D>
     /// an array with shape 3 × 5 × 5.
     ///
     /// <img src="https://rust-ndarray.github.io/ndarray/images/split_at.svg" width="300px" height="271px">
-    pub fn split_at(self, axis: Axis, index: Ix)
-        -> (Self, Self)
-    {
-        // NOTE: Keep this in sync with the ArrayViewMut version
-        assert!(index <= self.len_of(axis));
-        let left_ptr = self.ptr;
-        let right_ptr = if index == self.len_of(axis) {
-            self.ptr
-        } else {
-            let offset = stride_offset(index, self.strides.axis(axis));
-            unsafe {
-                self.ptr.offset(offset)
-            }
-        };
-
-        let mut dim_left = self.dim.clone();
-        dim_left.set_axis(axis, index);
-        let left = unsafe {
-            Self::new_(left_ptr, dim_left, self.strides.clone())
-        };
-
-        let mut dim_right = self.dim;
-        let right_len  = dim_right.axis(axis) - index;
-        dim_right.set_axis(axis, right_len);
-        let right = unsafe {
-            Self::new_(right_ptr, dim_right, self.strides)
-        };
-
-        (left, right)
+    pub fn split_at(self, axis: Axis, index: Ix) -> (Self, Self) {
+        unsafe {
+            let (left, right) = self.into_raw_view().split_at(axis, index);
+            (left.deref_into_view(), right.deref_into_view())
+        }
     }
 
     /// Return the array’s data as a slice, if it is contiguous and in standard order.
@@ -183,6 +151,11 @@ impl<'a, A, D> ArrayView<'a, A, D>
             None
         }
     }
+
+    /// Converts to a raw array view.
+    pub(crate) fn into_raw_view(self) -> RawArrayView<A, D> {
+        unsafe { RawArrayView::new_(self.ptr, self.dim, self.strides) }
+    }
 }
 
 
@@ -408,15 +381,7 @@ impl<'a, A, D> ArrayViewMut<'a, A, D>
     pub unsafe fn from_shape_ptr<Sh>(shape: Sh, ptr: *mut A) -> Self
         where Sh: Into<StrideShape<D>>
     {
-        let shape = shape.into();
-        let dim = shape.dim;
-        let strides = shape.strides;
-        if cfg!(debug_assertions) {
-            assert!(!ptr.is_null(), "The pointer must be non-null.");
-            assert!(is_aligned(ptr), "The pointer must be aligned.");
-            dimension::max_abs_offset_check_overflow::<A, _>(&dim, &strides).unwrap();
-        }
-        ArrayViewMut::new_(ptr, dim, strides)
+        RawArrayViewMut::from_shape_ptr(shape, ptr).deref_into_view_mut()
     }
 
     /// Convert the view into an `ArrayViewMut<'b, A, D>` where `'b` is a lifetime
@@ -433,35 +398,11 @@ impl<'a, A, D> ArrayViewMut<'a, A, D>
     /// before the split and one mutable view after the split.
     ///
     /// **Panics** if `axis` or `index` is out of bounds.
-    pub fn split_at(self, axis: Axis, index: Ix)
-        -> (Self, Self)
-    {
-        // NOTE: Keep this in sync with the ArrayView version
-        assert!(index <= self.len_of(axis));
-        let left_ptr = self.ptr;
-        let right_ptr = if index == self.len_of(axis) {
-            self.ptr
-        } else {
-            let offset = stride_offset(index, self.strides.axis(axis));
-            unsafe {
-                self.ptr.offset(offset)
-            }
-        };
-
-        let mut dim_left = self.dim.clone();
-        dim_left.set_axis(axis, index);
-        let left = unsafe {
-            Self::new_(left_ptr, dim_left, self.strides.clone())
-        };
-
-        let mut dim_right = self.dim;
-        let right_len  = dim_right.axis(axis) - index;
-        dim_right.set_axis(axis, right_len);
-        let right = unsafe {
-            Self::new_(right_ptr, dim_right, self.strides)
-        };
-
-        (left, right)
+    pub fn split_at(self, axis: Axis, index: Ix) -> (Self, Self) {
+        unsafe {
+            let (left, right) = self.into_raw_view_mut().split_at(axis, index);
+            (left.deref_into_view_mut(), right.deref_into_view_mut())
+        }
     }
 
     /// Return the array’s data as a slice, if it is contiguous and in standard order.
@@ -605,6 +546,11 @@ impl<'a, A, D> ArrayViewMut<'a, A, D>
         }
     }
 
+    /// Converts to a mutable raw array view.
+    pub(crate) fn into_raw_view_mut(self) -> RawArrayViewMut<A, D> {
+        unsafe { RawArrayViewMut::new_(self.ptr, self.dim, self.strides) }
+    }
+
     #[inline]
     pub(crate) fn into_base_iter(self) -> Baseiter<A, D> {
         unsafe {