Cleaned up trait usage and added forbid_unsafe to parts (#695)

src/array/map/mod.rs

@@ -4,7 +4,6 @@ use crate::{
     bitmap::Bitmap,
     buffer::Buffer,
     datatypes::{DataType, Field},
-    types::Index,
 };
 
 use super::{new_empty_array, specification::check_offsets, Array};
@@ -138,12 +137,12 @@ impl MapArray {
     pub fn value(&self, i: usize) -> Box<dyn Array> {
         let offset = self.offsets[i];
         let offset_1 = self.offsets[i + 1];
-        let length = (offset_1 - offset).to_usize();
+        let length = (offset_1 - offset) as usize;
 
         // Safety:
         // One of the invariants of the struct
         // is that offsets are in bounds
-        unsafe { self.field.slice_unchecked(offset.to_usize(), length) }
+        unsafe { self.field.slice_unchecked(offset as usize, length) }
     }
 
     /// Returns the element at index `i`.
@@ -153,9 +152,9 @@ impl MapArray {
     pub unsafe fn value_unchecked(&self, i: usize) -> Box<dyn Array> {
         let offset = *self.offsets.get_unchecked(i);
         let offset_1 = *self.offsets.get_unchecked(i + 1);
-        let length = (offset_1 - offset).to_usize();
+        let length = (offset_1 - offset) as usize;
 
-        self.field.slice_unchecked(offset.to_usize(), length)
+        self.field.slice_unchecked(offset as usize, length)
     }
 }
 

src/io/avro/mod.rs

@@ -1,4 +1,5 @@
 #![deny(missing_docs)]
+#![forbid(unsafe_code)]
 //! Read and write from and to Apache Avro
 
 pub mod read;

src/io/csv/mod.rs

@@ -1,4 +1,5 @@
 #![deny(missing_docs)]
+#![forbid(unsafe_code)]
 //! Convert data between the Arrow and CSV (comma-separated values).
 
 use crate::error::ArrowError;

src/io/csv/write/serialize.rs

@@ -2,7 +2,7 @@ use lexical_core::ToLexical;
 
 use crate::datatypes::IntegerType;
 use crate::temporal_conversions;
-use crate::types::{Index, NativeType};
+use crate::types::NativeType;
 use crate::util::lexical_to_bytes_mut;
 use crate::{
     array::{Array, BinaryArray, BooleanArray, PrimitiveArray, Utf8Array},
@@ -405,7 +405,7 @@ pub fn new_serializer<'a>(
 /// Helper for serializing a dictonary array. The generic parameters are:
 /// - `K` for the type of the keys of the dictionary
 /// - `O` for the type of the offsets in the Utf8Array: {i32, i64}
-fn serialize_utf8_dict<'a, K: DictionaryKey + Index, O: Offset>(
+fn serialize_utf8_dict<'a, K: DictionaryKey, O: Offset>(
     array: &'a dyn Any,
 ) -> Box<dyn StreamingIterator<Item = [u8]> + 'a> {
     let array = array.downcast_ref::<DictionaryArray<K>>().unwrap();
@@ -419,7 +419,7 @@ fn serialize_utf8_dict<'a, K: DictionaryKey + Index, O: Offset>(
         keys.iter(),
         move |x, buf| {
             if let Some(x) = x {
-                let i = Index::to_usize(x);
+                let i = x.to_usize().unwrap();
                 if !values.is_null(i) {
                     let val = values.value(i);
                     buf.extend_from_slice(val.as_bytes());

src/io/ipc/read/array/binary.rs

@@ -1,5 +1,4 @@
 use std::collections::VecDeque;
-use std::convert::TryInto;
 use std::io::{Read, Seek};
 
 use arrow_format::ipc;
@@ -8,7 +7,6 @@ use crate::array::{BinaryArray, Offset};
 use crate::buffer::Buffer;
 use crate::datatypes::DataType;
 use crate::error::Result;
-use crate::types::NativeType;
 
 use super::super::deserialize::Node;
 use super::super::read_basic::*;
@@ -21,10 +19,7 @@ pub fn read_binary<O: Offset, R: Read + Seek>(
     block_offset: u64,
     is_little_endian: bool,
     compression: Option<ipc::Message::BodyCompression>,
-) -> Result<BinaryArray<O>>
-where
-    Vec<u8>: TryInto<O::Bytes> + TryInto<<u8 as NativeType>::Bytes>,
-{
+) -> Result<BinaryArray<O>> {
     let field_node = field_nodes.pop_front().unwrap();
 
     let validity = read_validity(

src/io/ipc/read/array/utf8.rs

@@ -1,5 +1,4 @@
 use std::collections::VecDeque;
-use std::convert::TryInto;
 use std::io::{Read, Seek};
 
 use arrow_format::ipc;
@@ -8,7 +7,6 @@ use crate::array::{Offset, Utf8Array};
 use crate::buffer::Buffer;
 use crate::datatypes::DataType;
 use crate::error::Result;
-use crate::types::NativeType;
 
 use super::super::deserialize::Node;
 use super::super::read_basic::*;
@@ -21,10 +19,7 @@ pub fn read_utf8<O: Offset, R: Read + Seek>(
     block_offset: u64,
     is_little_endian: bool,
     compression: Option<ipc::Message::BodyCompression>,
-) -> Result<Utf8Array<O>>
-where
-    Vec<u8>: TryInto<O::Bytes> + TryInto<<u8 as NativeType>::Bytes>,
-{
+) -> Result<Utf8Array<O>> {
     let field_node = field_nodes.pop_front().unwrap();
 
     let validity = read_validity(

src/io/json/mod.rs

@@ -1,4 +1,5 @@
 #![deny(missing_docs)]
+#![forbid(unsafe_code)]
 //! Convert data between the Arrow memory format and JSON line-delimited records.
 
 mod read;