backout VarArray non-copy changes

Author: JamesMc86

hdf5-types/src/array.rs

@@ -6,13 +6,29 @@ use std::ptr;
 use std::slice;
 
 #[repr(C)]
-pub struct VarLenArray<T> {
+pub struct VarLenArray<T: Copy> {
     len: usize,
     ptr: *const T,
     tag: PhantomData<T>,
 }
 
-impl<T> VarLenArray<T> {
+impl<T: Copy> VarLenArray<T> {
+    pub unsafe fn from_parts(p: *const T, len: usize) -> Self {
+        let (len, ptr) = if !p.is_null() && len != 0 {
+            let dst = crate::malloc(len * mem::size_of::<T>());
+            ptr::copy_nonoverlapping(p, dst.cast(), len);
+            (len, dst)
+        } else {
+            (0, ptr::null_mut())
+        };
+        Self { len, ptr: ptr as *const _, tag: PhantomData }
+    }
+
+    #[inline]
+    pub fn from_slice(arr: &[T]) -> Self {
+        unsafe { Self::from_parts(arr.as_ptr(), arr.len()) }
+    }
+
     #[inline]
     pub fn as_ptr(&self) -> *const T {
         self.ptr
@@ -30,31 +46,11 @@ impl<T> VarLenArray<T> {
 
     #[inline]
     pub fn as_slice(&self) -> &[T] {
-        unsafe { slice::from_raw_parts(self.as_ptr(), self.len()) }
-    }
-}
-
-impl<T: Copy> VarLenArray<T> {
-    /// Creates a new `VarLenArray` from a slice by copying the source data.
-    #[inline]
-    pub fn from_slice(arr: &[T]) -> Self {
-        unsafe { Self::from_parts(arr.as_ptr(), arr.len()) }
-    }
-
-    /// Create a new `VarLenArray` from a ptr/len combo by copying the source data.
-    pub unsafe fn from_parts(p: *const T, len: usize) -> Self {
-        let (len, ptr) = if !p.is_null() && len != 0 {
-            let dst = crate::malloc(len * mem::size_of::<T>());
-            ptr::copy_nonoverlapping(p, dst.cast(), len);
-            (len, dst)
-        } else {
-            (0, ptr::null_mut())
-        };
-        Self { len, ptr: ptr as *const _, tag: PhantomData }
+        self
     }
 }
 
-impl<T> Drop for VarLenArray<T> {
+impl<T: Copy> Drop for VarLenArray<T> {
     fn drop(&mut self) {
         if !self.ptr.is_null() {
             unsafe {
@@ -75,15 +71,15 @@ impl<T: Copy> Clone for VarLenArray<T> {
     }
 }
 
-impl<T> Deref for VarLenArray<T> {
+impl<T: Copy> Deref for VarLenArray<T> {
     type Target = [T];
 
     #[inline]
     fn deref(&self) -> &[T] {
         if self.len == 0 || self.ptr.is_null() {
             &[]
         } else {
-            self.as_slice()
+            unsafe { slice::from_raw_parts(self.as_ptr(), self.len()) }
         }
     }
 }
@@ -139,7 +135,7 @@ impl<T: Copy + PartialEq, const N: usize> PartialEq<[T; N]> for VarLenArray<T> {
     }
 }
 
-impl<T: fmt::Debug> fmt::Debug for VarLenArray<T> {
+impl<T: Copy + fmt::Debug> fmt::Debug for VarLenArray<T> {
     #[inline]
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         self.as_slice().fmt(f)

hdf5-types/src/h5type.rs

@@ -347,7 +347,7 @@ unsafe impl<T: H5Type, const N: usize> H5Type for [T; N] {
     }
 }
 
-unsafe impl<T: H5Type> H5Type for VarLenArray<T> {
+unsafe impl<T: H5Type + Copy> H5Type for VarLenArray<T> {
     #[inline]
     fn type_descriptor() -> TypeDescriptor {
         TypeDescriptor::VarLenArray(Box::new(<T as H5Type>::type_descriptor()))