Remove impl IntoPyObject for &PyObjectRef and &PyRef

they doesn't give any benefit but just hide clone

vm/src/format.rs

@@ -1,7 +1,7 @@
 use crate::exceptions::PyBaseExceptionRef;
 use crate::function::PyFuncArgs;
 use crate::obj::{objstr, objtype};
-use crate::pyobject::{IntoPyObject, ItemProtocol, PyObjectRef, PyResult, TypeProtocol};
+use crate::pyobject::{ItemProtocol, PyObjectRef, PyResult, TypeProtocol};
 use crate::vm::VirtualMachine;
 use itertools::{Itertools, PeekingNext};
 use num_bigint::{BigInt, Sign};
@@ -823,8 +823,7 @@ impl FormatString {
                                 argument = vm.get_attribute(argument, attribute.as_str())?;
                             }
                             FieldNamePart::Index(index) => {
-                                // TODO Implement DictKey for usize so we can pass index directly
-                                argument = argument.get_item(&index.into_pyobject(vm), vm)?;
+                                argument = argument.get_item(index, vm)?;
                             }
                             FieldNamePart::StringIndex(index) => {
                                 argument = argument.get_item(&index, vm)?;

vm/src/frame.rs

@@ -947,7 +947,7 @@ impl ExecutingFrame<'_> {
     fn execute_subscript(&mut self, vm: &VirtualMachine) -> FrameResult {
         let b_ref = self.pop_value();
         let a_ref = self.pop_value();
-        let value = a_ref.get_item(&b_ref, vm)?;
+        let value = a_ref.get_item(b_ref, vm)?;
         self.push_value(value);
         Ok(None)
     }
@@ -963,7 +963,7 @@ impl ExecutingFrame<'_> {
     fn execute_delete_subscript(&mut self, vm: &VirtualMachine) -> FrameResult {
         let idx = self.pop_value();
         let obj = self.pop_value();
-        obj.del_item(&idx, vm)?;
+        obj.del_item(idx, vm)?;
         Ok(None)
     }
 
@@ -987,7 +987,7 @@ impl ExecutingFrame<'_> {
                 })?;
                 for (key, value) in dict {
                     if for_call {
-                        if map_obj.contains_key(&key, vm) {
+                        if map_obj.contains_key(key.clone(), vm) {
                             let key_repr = vm.to_repr(&key)?;
                             let msg = format!(
                                 "got multiple values for keyword argument {}",

vm/src/obj/objdict.rs

@@ -75,7 +75,7 @@ impl PyDictRef {
             } else if let Some(keys) = vm.get_method(dict_obj.clone(), "keys") {
                 let keys = objiter::get_iter(vm, &vm.invoke(&keys?, vec![])?)?;
                 while let Some(key) = objiter::get_next_object(vm, &keys)? {
-                    let val = dict_obj.get_item(&key, vm)?;
+                    let val = dict_obj.get_item(key.clone(), vm)?;
                     dict.insert(vm, key, val)?;
                 }
             } else {

vm/src/obj/objmappingproxy.rs

@@ -50,7 +50,7 @@ impl PyMappingProxy {
                 let key = PyStringRef::try_from_object(vm, key)?;
                 class.get_attr(key.as_str())
             }
-            MappingProxyInner::Dict(obj) => obj.get_item(&key, vm).ok(),
+            MappingProxyInner::Dict(obj) => obj.get_item(key, vm).ok(),
         };
         Ok(opt)
     }

vm/src/obj/objmemory.rs

@@ -60,7 +60,7 @@ impl PyMemoryView {
 
     #[pymethod(name = "__getitem__")]
     fn getitem(&self, needle: PyObjectRef, vm: &VirtualMachine) -> PyResult {
-        self.obj_ref.get_item(&needle, vm)
+        self.obj_ref.get_item(needle, vm)
     }
 
     #[pymethod(magic)]

vm/src/obj/objstr.rs

@@ -953,7 +953,7 @@ impl PyString {
 
         let mut translated = String::new();
         for c in self.value.chars() {
-            match table.get_item(&(c as u32).into_pyobject(vm), vm) {
+            match table.get_item((c as u32).into_pyobject(vm), vm) {
                 Ok(value) => {
                     if let Some(text) = value.payload::<PyString>() {
                         translated.push_str(&text.value);

vm/src/pyobject.rs

@@ -1160,12 +1160,6 @@ impl<T> IntoPyObject for PyRef<T> {
     }
 }
 
-impl<T> IntoPyObject for &PyRef<T> {
-    fn into_pyobject(self, _vm: &VirtualMachine) -> PyObjectRef {
-        self.obj.clone()
-    }
-}
-
 impl IntoPyObject for PyCallable {
     fn into_pyobject(self, _vm: &VirtualMachine) -> PyObjectRef {
         self.into_object()
@@ -1178,12 +1172,6 @@ impl IntoPyObject for PyObjectRef {
     }
 }
 
-impl IntoPyObject for &PyObjectRef {
-    fn into_pyobject(self, _vm: &VirtualMachine) -> PyObjectRef {
-        self.clone()
-    }
-}
-
 // Allows a built-in function to return any built-in object payload without
 // explicitly implementing `IntoPyObject`.
 impl<T> IntoPyObject for T