[nit] Remove trait bound af::HasEnum on struct definition and Drop impl for Array<T>

Author: ma2bd

src/core/array.rs

@@ -160,7 +160,7 @@ extern "C" {
 /// All operators(traits) from std::ops module implemented for Array object
 /// carry out element wise operations. For example, `*` does multiplication of
 /// elements at corresponding locations in two different Arrays.
-pub struct Array<T: HasAfEnum> {
+pub struct Array<T> {
     handle: af_array,
     /// The phantom marker denotes the
     /// allocation of data on compute device
@@ -701,10 +701,7 @@ where
 }
 
 /// To free resources when Array goes out of scope
-impl<T> Drop for Array<T>
-where
-    T: HasAfEnum,
-{
+impl<T> Drop for Array<T> {
     fn drop(&mut self) {
         unsafe {
             let ret_val = af_release_array(self.handle);