diff --git a/pyo3cls/src/defs.rs b/pyo3cls/src/defs.rs
index 3aa036ae..53482e16 100644
--- a/pyo3cls/src/defs.rs
+++ b/pyo3cls/src/defs.rs
@@ -439,68 +439,68 @@ pub const NUM: Proto = Proto {
         MethodProto::Binary {
             name: "__iadd__",
             arg: "Other",
-            pyres: true,
+            pyres: false,
             proto: "::pyo3::class::number::PyNumberIAddProtocol"},
         MethodProto::Binary {
             name: "__isub__",
             arg: "Other",
-            pyres: true,
+            pyres: false,
             proto: "::pyo3::class::number::PyNumberISubProtocol"},
         MethodProto::Binary {
             name: "__imul__",
             arg: "Other",
-            pyres: true,
+            pyres: false,
             proto: "::pyo3::class::number::PyNumberIMulProtocol"},
         MethodProto::Binary {
             name: "__imatmul__",
             arg: "Other",
-            pyres: true,
+            pyres: false,
             proto: "::pyo3::class::number::PyNumberIMatmulProtocol"},
         MethodProto::Binary {
             name: "__itruediv__",
             arg: "Other",
-            pyres: true,
+            pyres: false,
             proto: "::pyo3::class::number::PyNumberITruedivProtocol"},
         MethodProto::Binary {
             name: "__ifloordiv__",
             arg: "Other",
-            pyres: true,
+            pyres: false,
             proto: "::pyo3::class::number::PyNumberIFloordivProtocol"},
         MethodProto::Binary {
             name: "__imod__",
             arg: "Other",
-            pyres: true,
+            pyres: false,
             proto: "::pyo3::class::number::PyNumberIModProtocol"},
         MethodProto::Ternary {
             name: "__ipow__",
             arg1: "Other",
             arg2: "Modulo",
-            pyres: true,
+            pyres: false,
             proto: "::pyo3::class::number::PyNumberIPowProtocol"},
         MethodProto::Binary {
             name: "__ilshift__",
             arg: "Other",
-            pyres: true,
+            pyres: false,
             proto: "::pyo3::class::number::PyNumberILShiftProtocol"},
         MethodProto::Binary {
             name: "__irshift__",
             arg: "Other",
-            pyres: true,
+            pyres: false,
             proto: "::pyo3::class::number::PyNumberIRShiftProtocol"},
         MethodProto::Binary {
             name: "__iand__",
             arg: "Other",
-            pyres: true,
+            pyres: false,
             proto: "::pyo3::class::number::PyNumberIAndProtocol"},
         MethodProto::Binary {
             name: "__ixor__",
             arg: "Other",
-            pyres: true,
+            pyres: false,
             proto: "::pyo3::class::number::PyNumberIXorProtocol"},
         MethodProto::Binary {
             name: "__ior__",
             arg: "Other",
-            pyres: true,
+            pyres: false,
             proto: "::pyo3::class::number::PyNumberIOrProtocol"},
 
         MethodProto::Unary {
diff --git a/pyo3cls/src/func.rs b/pyo3cls/src/func.rs
index c6a4af63..7162e4c6 100644
--- a/pyo3cls/src/func.rs
+++ b/pyo3cls/src/func.rs
@@ -42,12 +42,14 @@ pub fn impl_method_proto(cls: &Box<syn::Ty>,
             match *meth {
                 MethodProto::Unary{name: _, pyres, proto} => {
                     let p = syn::Ident::from(proto);
-                    let succ = get_res_success(ty);
+                    let (ty, succ) = get_res_success(ty);
 
                     let tmp = extract_decl(syn::parse_item(
                         quote! {fn test(&self)
                                         -> <#cls as #p<'p>>::Result {}}.as_str()).unwrap());
                     sig.decl.output = tmp.output.clone();
+                    modify_self_ty(sig);
+                    modify_py_ty(sig);
 
                     if pyres {
                         quote! {
@@ -65,14 +67,14 @@ pub fn impl_method_proto(cls: &Box<syn::Ty>,
                     }
                 },
                 MethodProto::Binary{name: n, arg, pyres, proto} => {
-                    if sig.decl.inputs.len() < 2 {
+                    if sig.decl.inputs.len() <= 2 {
                         println!("Not enough arguments for {}", n);
                         return Tokens::new();
                     }
                     let p = syn::Ident::from(proto);
                     let arg_name = syn::Ident::from(arg);
                     let arg_ty = get_arg_ty(sig, 2);
-                    let succ = get_res_success(ty);
+                    let (ty, succ) = get_res_success(ty);
 
                     let tmp = extract_decl(syn::parse_item(
                         quote! {fn test(
@@ -85,6 +87,8 @@ pub fn impl_method_proto(cls: &Box<syn::Ty>,
                             arg: Option<<#cls as #p<'p>>::#arg_name>)
                                 -> <#cls as #p<'p>>::Result {}}.as_str()).unwrap());
                     modify_arg_ty(sig, 2, &tmp, &tmp2);
+                    modify_self_ty(sig);
+                    modify_py_ty(sig);
 
                     if pyres {
                         quote! {
@@ -104,7 +108,7 @@ pub fn impl_method_proto(cls: &Box<syn::Ty>,
                     }
                 },
                 MethodProto::Ternary{name: n, arg1, arg2, pyres, proto} => {
-                    if sig.decl.inputs.len() < 3 {
+                    if sig.decl.inputs.len() <= 3 {
                         print_err(format!("Not enough arguments {}", n), quote!(sig));
                         return Tokens::new();
                     }
@@ -113,7 +117,7 @@ pub fn impl_method_proto(cls: &Box<syn::Ty>,
                     let arg1_ty = get_arg_ty(sig, 2);
                     let arg2_name = syn::Ident::from(arg2);
                     let arg2_ty = get_arg_ty(sig, 3);
-                    let succ = get_res_success(ty);
+                    let (ty, succ) = get_res_success(ty);
 
                     // rewrite ty
                     let tmp = extract_decl(syn::parse_item(
@@ -130,6 +134,8 @@ pub fn impl_method_proto(cls: &Box<syn::Ty>,
                                 -> <#cls as #p<'p>>::Result {}}.as_str()).unwrap());
                     modify_arg_ty(sig, 2, &tmp, &tmp2);
                     modify_arg_ty(sig, 3, &tmp, &tmp2);
+                    modify_self_ty(sig);
+                    modify_py_ty(sig);
 
                     if pyres {
                         quote! {
@@ -151,7 +157,7 @@ pub fn impl_method_proto(cls: &Box<syn::Ty>,
                     }
                 },
                 MethodProto::Quaternary{name: n, arg1, arg2, arg3, proto} => {
-                    if sig.decl.inputs.len() < 4 {
+                    if sig.decl.inputs.len() <= 4 {
                         print_err(format!("Not enough arguments {}", n), quote!(sig));
                         return Tokens::new();
                     }
@@ -162,7 +168,7 @@ pub fn impl_method_proto(cls: &Box<syn::Ty>,
                     let arg2_ty = get_arg_ty(sig, 3);
                     let arg3_name = syn::Ident::from(arg3);
                     let arg3_ty = get_arg_ty(sig, 4);
-                    let succ = get_res_success(ty);
+                    let (ty, succ) = get_res_success(ty);
 
                     // rewrite ty
                     let tmp = extract_decl(syn::parse_item(
@@ -182,6 +188,8 @@ pub fn impl_method_proto(cls: &Box<syn::Ty>,
                     modify_arg_ty(sig, 2, &tmp, &tmp2);
                     modify_arg_ty(sig, 3, &tmp, &tmp2);
                     modify_arg_ty(sig, 4, &tmp, &tmp2);
+                    modify_self_ty(sig);
+                    modify_py_ty(sig);
 
                     quote! {
                         impl<'p> #p<'p> for #cls {
@@ -202,7 +210,7 @@ pub fn impl_method_proto(cls: &Box<syn::Ty>,
 
 // TODO: better arg ty detection
 fn get_arg_ty(sig: &syn::MethodSig, idx: usize) -> syn::Ty {
-    match sig.decl.inputs[idx] {
+    let mut ty = match sig.decl.inputs[idx] {
         syn::FnArg::Captured(_, ref arg_ty) => {
             match arg_ty {
                 &syn::Ty::Path(_, ref path) => {
@@ -220,25 +228,38 @@ fn get_arg_ty(sig: &syn::MethodSig, idx: usize) -> syn::Ty {
                     }
                     arg_ty.clone()
                 },
-                _ => {
-                    arg_ty.clone()
-                }
+                _ => arg_ty.clone()
             }
         },
-        _ =>
-            panic!("fn arg type is not supported"),
+        _ => panic!("fn arg type is not supported"),
+    };
+
+    match ty {
+        syn::Ty::Rptr(ref mut lifetime, _) => {
+            match lifetime {
+                &mut None => {
+                    *lifetime = Some(syn::Lifetime {ident: syn::Ident::from("'p")})
+                }
+                _ => (),
+            }
+        }
+        _ => ()
     }
+
+    ty
 }
 
 // Success
-fn get_res_success(ty: &syn::Ty) -> syn::Ty {
-    match ty {
+fn get_res_success(ty: &syn::Ty) -> (Tokens, syn::Ty) {
+    let result;
+    let mut succ = match ty {
         &syn::Ty::Path(_, ref path) => {
             if let Some(segment) = path.segments.last() {
                 match segment.ident.as_ref() {
                     // check result type
                     "PyResult" => match segment.parameters {
                         syn::PathParameters::AngleBracketed(ref data) => {
+                            result = true;
                             data.types[0].clone()
                         },
                         _ => panic!("fn result type is not supported"),
@@ -253,7 +274,40 @@ fn get_res_success(ty: &syn::Ty) -> syn::Ty {
             }
         }
         _ => panic!("not supported: {:?}", ty),
+    };
+
+    // add lifetime to Py<T>
+    match succ {
+        syn::Ty::Path(_, ref mut path) => {
+            let last = path.segments.len()-1;
+            let seg = path.segments[last].clone();
+
+            if seg.ident.as_ref() == "Py" {
+                if let syn::PathParameters::AngleBracketed(ref data) = seg.parameters {
+                    path.segments[last] = syn::PathSegment{
+                        ident: seg.ident.clone(),
+                        parameters: syn::PathParameters::AngleBracketed(
+                            syn::AngleBracketedParameterData{
+                                lifetimes: vec![syn::Lifetime {
+                                    ident: syn::Ident::from("'p")}],
+                                types: data.types.clone(),
+                                bindings: data.bindings.clone(),
+                            })
+                    }
+                }
+            }
+        }
+        _ => (),
     }
+
+    // result
+    let res = if result {
+        quote! {PyResult<#succ>}
+    } else {
+        quote! {#ty}
+    };
+    
+    (res, succ)
 }
 
 
@@ -285,13 +339,54 @@ fn modify_arg_ty(sig: &mut syn::MethodSig, idx: usize,
                 }
             }
         },
-        _ =>
-            panic!("not supported"),
+        _ => panic!("not supported"),
     }
 
     sig.decl.output = decl1.output.clone();
 }
 
+fn modify_self_ty(sig: &mut syn::MethodSig)
+{
+    match sig.decl.inputs[0] {
+        syn::FnArg::SelfRef(ref mut lifetime, _) => {
+            *lifetime = Some(syn::Lifetime {ident: syn::Ident::from("'p")})
+        },
+        _ => panic!("not supported"),
+    }
+}
+
+// modify Python signature
+fn modify_py_ty(sig: &mut syn::MethodSig)
+{
+    match sig.decl.inputs[1] {
+        syn::FnArg::Captured(_, ref mut arg_ty) => {
+            match arg_ty {
+                &mut syn::Ty::Path(_, ref mut path) => {
+                    let last = path.segments.len()-1;
+                    let seg = path.segments[last].clone();
+                    if seg.ident.as_ref() == "Python" {
+                        if let syn::PathParameters::AngleBracketed(ref data) = seg.parameters {
+                            path.segments[last] = syn::PathSegment{
+                                ident: seg.ident.clone(),
+                                parameters: syn::PathParameters::AngleBracketed(
+                                    syn::AngleBracketedParameterData{
+                                        lifetimes: vec![syn::Lifetime {
+                                            ident: syn::Ident::from("'p")}],
+                                        types: data.types.clone(),
+                                        bindings: data.bindings.clone(),
+                                    })
+                            }
+                        }
+                    }
+                },
+                _ => (),
+            }
+        },
+        _ => panic!("not supported"),
+    }
+}
+
+
 fn fix_name(pat: &syn::Pat, arg: &syn::FnArg) -> syn::FnArg {
     match arg {
         &syn::FnArg::Captured(_, ref arg_ty) =>
diff --git a/pyo3cls/src/py_class.rs b/pyo3cls/src/py_class.rs
index 6a3df929..2162184d 100644
--- a/pyo3cls/src/py_class.rs
+++ b/pyo3cls/src/py_class.rs
@@ -8,7 +8,8 @@ pub fn build_py_class(ast: &mut syn::DeriveInput) -> Tokens {
     let base = syn::Ident::from("_pyo3::PyObject");
 
     match ast.body {
-        syn::Body::Struct(syn::VariantData::Struct(_)) => (),
+        syn::Body::Struct(syn::VariantData::Struct(_)) => {
+        },
         _ => panic!("#[class] can only be used with notmal structs"),
     }
 
@@ -22,7 +23,6 @@ pub fn build_py_class(ast: &mut syn::DeriveInput) -> Tokens {
         const #dummy_const: () = {
             extern crate pyo3 as _pyo3;
             use std;
-            use pyo3::python::IntoPythonPointer;
 
             #tokens
         };
@@ -30,6 +30,7 @@ pub fn build_py_class(ast: &mut syn::DeriveInput) -> Tokens {
 }
 
 fn impl_class(cls: &syn::Ident, base: &syn::Ident) -> Tokens {
+    let token_name = syn::Ident::from("__py_token");
     let cls_name = quote! { #cls }.as_str().to_string();
 
     quote! {
@@ -60,12 +61,22 @@ fn impl_class(cls: &syn::Ident, base: &syn::Ident) -> Tokens {
             }
         }
 
-        impl _pyo3::IntoPyObject for #cls {
+        impl _pyo3::python::ToPythonPointer for #cls {
             #[inline]
-            fn into_object<'p>(self, py: Python<'p>) -> Py<'p, PyObject> where Self: Sized
-            {
-                let ptr = py.init(self).into_ptr();
-                _pyo3::PyObject::from_owned_ptr(py, ptr)
+            fn as_ptr(&self) -> *mut ffi::PyObject {
+                let offset = <#cls as _pyo3::typeob::PyTypeInfo>::offset();
+                unsafe {
+                    {self as *const _ as *mut u8}.offset(-offset) as *mut _pyo3::ffi::PyObject
+                }
+            }
+        }
+
+        impl _pyo3::python::PyClone for #cls {
+            fn clone_ref(&self) -> PyPtr<#cls> {
+                unsafe {
+                    let ptr = <#cls as _pyo3::python::ToPythonPointer>::as_ptr(self);
+                    _pyo3::PyPtr::from_borrowed_ptr(ptr)
+                }
             }
         }
     }
diff --git a/pyo3cls/src/py_method.rs b/pyo3cls/src/py_method.rs
index caa6c53d..ef37166c 100644
--- a/pyo3cls/src/py_method.rs
+++ b/pyo3cls/src/py_method.rs
@@ -47,7 +47,7 @@ pub fn impl_wrap(cls: &Box<syn::Ty>, name: &syn::Ident, spec: &FnSpec) -> Tokens
                                   kwargs: *mut _pyo3::ffi::PyObject) -> *mut _pyo3::ffi::PyObject
         {
             const LOCATION: &'static str = concat!(stringify!(#cls),".",stringify!(#name),"()");
-            _pyo3::callback::cb_meth::<_, *mut _pyo3::ffi::PyObject>(LOCATION, |py| {
+            _pyo3::callback::cb_meth(LOCATION, |py| {
                 let mut slf: Py<#cls> = Py::from_borrowed_ptr(py, slf);
 
                 let args: _pyo3::Py<_pyo3::PyTuple> = _pyo3::Py::from_borrowed_ptr(py, args);
@@ -70,18 +70,24 @@ pub fn impl_proto_wrap(cls: &Box<syn::Ty>, name: &syn::Ident, spec: &FnSpec) ->
     let body = impl_arg_params(&spec, cb);
 
     quote! {
-        unsafe extern "C" fn wrap<'p>(
-            slf: *mut _pyo3::ffi::PyObject,
-            args: *mut _pyo3::ffi::PyObject,
-            kwargs: *mut _pyo3::ffi::PyObject) -> *mut _pyo3::ffi::PyObject
+        #[allow(unused_mut)]
+        unsafe extern "C" fn wrap(slf: *mut _pyo3::ffi::PyObject,
+                                  args: *mut _pyo3::ffi::PyObject,
+                                  kwargs: *mut _pyo3::ffi::PyObject) -> *mut _pyo3::ffi::PyObject
         {
             const LOCATION: &'static str = concat!(stringify!(#cls),".",stringify!(#name),"()");
-            _pyo3::callback::handle(LOCATION, _pyo3::callback::PyObjectCallbackConverter, |py| {
+            _pyo3::callback::cb_meth(LOCATION, |py| {
+                let mut slf: Py<#cls> = Py::from_borrowed_ptr(py, slf);
+
                 let args: _pyo3::Py<_pyo3::PyTuple> = _pyo3::Py::from_borrowed_ptr(py, args);
                 let kwargs: Option<_pyo3::Py<_pyo3::PyDict>> =
                     _pyo3::argparse::get_kwargs(py, kwargs);
 
-                #body
+                let result = {
+                    #body
+                };
+                _pyo3::callback::cb_convert(
+                    _pyo3::callback::PyObjectCallbackConverter, py, result)
             })
         }
     }
@@ -91,20 +97,28 @@ pub fn impl_proto_wrap(cls: &Box<syn::Ty>, name: &syn::Ident, spec: &FnSpec) ->
 pub fn impl_wrap_new(cls: &Box<syn::Ty>, name: &syn::Ident, spec: &FnSpec) -> Tokens {
     let cb = impl_class_new(cls, name, spec);
     let body = impl_arg_params(spec, cb);
+    let output = &spec.output;
 
     quote! {
+        #[allow(unused_mut)]
         unsafe extern "C" fn wrap(cls: *mut _pyo3::ffi::PyTypeObject,
                                   args: *mut _pyo3::ffi::PyObject,
                                   kwargs: *mut _pyo3::ffi::PyObject) -> *mut _pyo3::ffi::PyObject
         {
-            const LOCATION: &'static str = concat!(
-                stringify!(#cls), ".", stringify!(#name), "()");
-            _pyo3::callback::handle(LOCATION, _pyo3::callback::PyObjectCallbackConverter, |py| {
+            const LOCATION: &'static str = concat!(stringify!(#cls),".",stringify!(#name), "()");
+
+            _pyo3::callback::cb_meth(LOCATION, |py| {
+                let cls: _pyo3::Py<_pyo3::PyType> = _pyo3::Py::from_borrowed_ptr(
+                    py, cls as *mut _pyo3::ffi::PyObject);
                 let args: _pyo3::Py<_pyo3::PyTuple> = _pyo3::Py::from_borrowed_ptr(py, args);
                 let kwargs: Option<_pyo3::Py<_pyo3::PyDict>> =
                     _pyo3::argparse::get_kwargs(py, kwargs);
 
-                #body
+                let result: #output = {
+                    #body
+                };
+                _pyo3::callback::cb_convert(
+                    _pyo3::callback::PyObjectCallbackConverter, py, result)
             })
         }
     }
@@ -120,8 +134,8 @@ fn impl_wrap_getter(cls: &Box<syn::Ty>, name: &syn::Ident, _spec: &FnSpec) -> To
         {
             const LOCATION: &'static str = concat!(
                 stringify!(#cls), ".getter_", stringify!(#name), "()");
-            _pyo3::callback::handle(LOCATION, _pyo3::callback::PyObjectCallbackConverter, |py| {
-                let slf: _pyo3::Py<#cls> = _pyo3::Py::from_borrowed_ptr(py, slf);
+            _pyo3::callback::cb_unary::<#cls, _, _, _>(
+                LOCATION, slf, _pyo3::callback::PyObjectCallbackConverter, |py, slf| {
                 slf.#name(py)
             })
         }
@@ -130,25 +144,33 @@ fn impl_wrap_getter(cls: &Box<syn::Ty>, name: &syn::Ident, _spec: &FnSpec) -> To
 
 /// Generate functiona wrapper (PyCFunction, PyCFunctionWithKeywords)
 fn impl_wrap_setter(cls: &Box<syn::Ty>, name: &syn::Ident, spec: &FnSpec) -> Tokens {
+    if spec.args.len() < 1 {
+        println!("Not enough arguments for setter {}::{}", quote!{#cls}, name);
+    }
     let val_ty = spec.args[0].ty;
 
     quote! {
+        #[allow(unused_mut)]
         unsafe extern "C" fn wrap(slf: *mut _pyo3::ffi::PyObject,
                                   value: *mut _pyo3::ffi::PyObject,
                                   _: *mut _pyo3::c_void) -> _pyo3::c_int
         {
             const LOCATION: &'static str = concat!(
                 stringify!(#cls), ".setter", stringify!(#name), "()");
-            _pyo3::callback::handle(LOCATION, _pyo3::callback::UnitCallbackConverter, |py| {
-                let slf: _pyo3::Py<#cls> = _pyo3::Py::from_borrowed_ptr(py, slf);
+            _pyo3::callback::cb_setter(LOCATION, |py| {
+                let mut slf = _pyo3::Py::<#cls>::from_borrowed_ptr(py, slf);
                 let value = _pyo3::PyObject::from_borrowed_ptr(py, value);
 
-                match <#val_ty as _pyo3::FromPyObject>::extract(&value) {
-                    Ok(val) => {
-                        let ret = slf.#name(val);
-                        ret.map(|o| ())
-                    }
+                let result = match <#val_ty as _pyo3::FromPyObject>::extract(&value) {
+                    Ok(val) => slf.#name(py, val),
                     Err(e) => Err(e)
+                };
+                match result {
+                    Ok(_) => 0,
+                    Err(e) => {
+                        e.restore(py);
+                        -1
+                    }
                 }
             })
         }
@@ -156,19 +178,17 @@ fn impl_wrap_setter(cls: &Box<syn::Ty>, name: &syn::Ident, spec: &FnSpec) -> Tok
 }
 
 
-fn impl_call(cls: &Box<syn::Ty>, fname: &syn::Ident, spec: &FnSpec) -> Tokens {
+fn impl_call(_cls: &Box<syn::Ty>, fname: &syn::Ident, spec: &FnSpec) -> Tokens {
     let names: Vec<&syn::Ident> = spec.args.iter().map(|item| item.name).collect();
     quote! {{
-        slf.#fname(py, #(#names),*)
+        slf.as_mut().#fname(py, #(#names),*)
     }}
 }
 
 fn impl_class_new(cls: &Box<syn::Ty>, fname: &syn::Ident, spec: &FnSpec) -> Tokens {
     let names: Vec<&syn::Ident> = spec.args.iter().map(|item| item.name).collect();
     quote! {{
-        let cls: _pyo3::Py<_pyo3::PyType> = _pyo3::Py::from_borrowed_ptr(
-            py, cls as *mut _pyo3::ffi::PyObject);
-        #cls::#fname(&cls, #(#names),*)
+        #cls::#fname(&cls, py, #(#names),*)
     }}
 }
 
diff --git a/pyo3cls/src/py_proto.rs b/pyo3cls/src/py_proto.rs
index 0b2eb8d7..32e1dd35 100644
--- a/pyo3cls/src/py_proto.rs
+++ b/pyo3cls/src/py_proto.rs
@@ -95,8 +95,7 @@ fn impl_proto_impl(ty: &Box<syn::Ty>, impls: &mut Vec<syn::ImplItem>, proto: &de
                         let name = syn::Ident::from(m.name);
                         let proto = syn::Ident::from(m.proto);
 
-                        let fn_spec = FnSpec::parse(
-                            &iimpl.ident, sig, &mut iimpl.attrs);
+                        let fn_spec = FnSpec::parse(&iimpl.ident, sig, &mut iimpl.attrs);
                         let meth = py_method::impl_proto_wrap(ty, &iimpl.ident, &fn_spec);
 
                         py_methods.push(
diff --git a/src/callback.rs b/src/callback.rs
index 84a2cc51..71ae74d3 100644
--- a/src/callback.rs
+++ b/src/callback.rs
@@ -21,7 +21,7 @@ pub trait CallbackConverter<S> {
 
 pub struct PyObjectCallbackConverter;
 
-impl <S> CallbackConverter<S> for PyObjectCallbackConverter
+impl<S> CallbackConverter<S> for PyObjectCallbackConverter
     where S: IntoPyObject
 {
     type R = *mut ffi::PyObject;
@@ -90,7 +90,7 @@ impl CallbackConverter<()> for UnitCallbackConverter {
     }
 }
 
-pub struct IterNextResultConverter;
+/*pub struct IterNextResultConverter;
 
 impl <T> CallbackConverter<Option<T>>
     for IterNextResultConverter
@@ -112,7 +112,7 @@ impl <T> CallbackConverter<Option<T>>
     fn error_value() -> *mut ffi::PyObject {
         ptr::null_mut()
     }
-}
+}*/
 
 pub trait WrappingCastTo<T> {
     fn wrapping_cast(self) -> T;
@@ -250,7 +250,7 @@ pub unsafe fn cb_unary_unit<Slf, F>(location: &str, slf: *mut ffi::PyObject, f:
     ret
 }
 
-pub unsafe fn cb_meth<F, R>(location: &str, f: F) -> *mut ffi::PyObject
+pub unsafe fn cb_meth<F>(location: &str, f: F) -> *mut ffi::PyObject
     where F: for<'p> FnOnce(Python<'p>) -> *mut ffi::PyObject,
           F: panic::UnwindSafe
 {
@@ -270,6 +270,26 @@ pub unsafe fn cb_meth<F, R>(location: &str, f: F) -> *mut ffi::PyObject
     ret
 }
 
+pub unsafe fn cb_setter<F>(location: &str, f: F) -> c_int
+    where F: for<'p> FnOnce(Python<'p>) -> c_int,
+          F: panic::UnwindSafe
+{
+    let guard = AbortOnDrop(location);
+    let ret = panic::catch_unwind(|| {
+        let py = Python::assume_gil_acquired();
+        f(py)
+    });
+    let ret = match ret {
+        Ok(r) => r,
+        Err(ref err) => {
+            handle_panic(Python::assume_gil_acquired(), err);
+            -1
+        }
+    };
+    mem::forget(guard);
+    ret
+}
+
 #[inline]
 pub unsafe fn cb_convert<C, T>(_c: C, py: Python, value: PyResult<T>) -> C::R
     where C: CallbackConverter<T>
diff --git a/src/class/async.rs b/src/class/async.rs
index 4699c71c..90983ed2 100644
--- a/src/class/async.rs
+++ b/src/class/async.rs
@@ -24,13 +24,13 @@ pub trait PyAsyncProtocol<'p>: PyTypeInfo + Sized + 'static {
     fn __aiter__(&'p self, py: Python<'p>)
                  -> Self::Result where Self: PyAsyncAiterProtocol<'p> { unimplemented!() }
 
-    fn __anext__(&'p self, py: Python<'p>)
+    fn __anext__(&'p mut self, py: Python<'p>)
                  -> Self::Result where Self: PyAsyncAnextProtocol<'p> { unimplemented!() }
 
-    fn __aenter__(&'p self, py: Python<'p>)
+    fn __aenter__(&'p mut self, py: Python<'p>)
                   -> Self::Result where Self: PyAsyncAenterProtocol<'p> { unimplemented!() }
 
-    fn __aexit__(&'p self, py: Python<'p>,
+    fn __aexit__(&'p mut self, py: Python<'p>,
                  exc_type: Option<Self::ExcType>,
                  exc_value: Option<Self::ExcValue>,
                  traceback: Option<Self::Traceback>)
diff --git a/src/class/basic.rs b/src/class/basic.rs
index 295bd2b2..cdafe434 100644
--- a/src/class/basic.rs
+++ b/src/class/basic.rs
@@ -31,10 +31,10 @@ pub trait PyObjectProtocol<'p>: PyTypeInfo + Sized + 'static {
     fn __getattr__(&'p self, py: Python<'p>, name: Self::Name)
                    -> Self::Result where Self: PyObjectGetAttrProtocol<'p> {unimplemented!()}
 
-    fn __setattr__(&'p self, py: Python<'p>, name: Self::Name, value: Self::Value)
+    fn __setattr__(&'p mut self, py: Python<'p>, name: Self::Name, value: Self::Value)
                    -> Self::Result where Self: PyObjectSetAttrProtocol<'p> {unimplemented!()}
 
-    fn __delattr__(&'p self, py: Python<'p>, name: Self::Name)
+    fn __delattr__(&'p mut self, py: Python<'p>, name: Self::Name)
                    -> Self::Result where Self: PyObjectDelAttrProtocol<'p> {unimplemented!()}
 
     fn __str__(&'p self, py: Python<'p>)
diff --git a/src/class/iter.rs b/src/class/iter.rs
index f5e8c6ca..67727594 100644
--- a/src/class/iter.rs
+++ b/src/class/iter.rs
@@ -16,10 +16,10 @@ use callback::PyObjectCallbackConverter;
 /// Iterator protocol
 #[allow(unused_variables)]
 pub trait PyIterProtocol<'p> : PyTypeInfo {
-    fn __iter__(&'p self, py: Python<'p>)
+    fn __iter__(&'p mut self, py: Python<'p>)
                 -> Self::Result where Self: PyIterIterProtocol<'p> { unimplemented!() }
 
-    fn __next__(&'p self, py: Python<'p>)
+    fn __next__(&'p mut self, py: Python<'p>)
                 -> Self::Result where Self: PyIterNextProtocol<'p> { unimplemented!() }
 
 }
diff --git a/src/class/macros.rs b/src/class/macros.rs
index 053220ad..296cd99a 100644
--- a/src/class/macros.rs
+++ b/src/class/macros.rs
@@ -17,7 +17,7 @@ macro_rules! py_unary_func {
             let ret = $crate::std::panic::catch_unwind(|| {
                 let py = $crate::Python::assume_gil_acquired();
                 let mut slf = $crate::Py::<T>::from_borrowed_ptr(py, slf);
-                let res = slf.$f(py).into();
+                let res = slf.as_mut().$f(py).into();
 
                 match res {
                     Ok(val) => {
@@ -131,7 +131,7 @@ macro_rules! py_binary_func{
 
                 let result = match arg.extract() {
                     Ok(arg) => {
-                        slf.$f(py, arg).into()
+                        slf.as_mut().$f(py, arg).into()
                     }
                     Err(e) => Err(e.into()),
                 };
@@ -164,6 +164,56 @@ macro_rules! py_binary_func{
     }}
 }
 
+#[macro_export]
+#[doc(hidden)]
+macro_rules! py_binary_self_func{
+    ($trait:ident, $class:ident :: $f:ident) => {{
+        #[allow(unused_mut)]
+        unsafe extern "C" fn wrap<T>(slf: *mut ffi::PyObject,
+                                     arg: *mut ffi::PyObject) -> *mut $crate::ffi::PyObject
+            where T: for<'p> $trait<'p>
+        {
+            const LOCATION: &'static str = concat!(stringify!($class), ".", stringify!($f), "()");
+
+            let guard = $crate::callback::AbortOnDrop(LOCATION);
+            let ret = $crate::std::panic::catch_unwind(|| {
+                let py = $crate::Python::assume_gil_acquired();
+                let mut slf1 = $crate::Py::<T>::from_borrowed_ptr(py, slf);
+                let arg = $crate::PyObject::from_borrowed_ptr(py, arg);
+
+                let result = match arg.extract() {
+                    Ok(arg) => {
+                        slf1.as_mut().$f(py, arg).into()
+                    }
+                    Err(e) => Err(e.into()),
+                };
+
+                match result {
+                    Ok(_) => {
+                        slf
+                    }
+                    Err(e) => {
+                        e.restore(py);
+                        $crate::std::ptr::null_mut()
+                    }
+                }
+            });
+
+            let ret = match ret {
+                Ok(r) => r,
+                Err(ref err) => {
+                    $crate::callback::handle_panic($crate::Python::assume_gil_acquired(), err);
+                    $crate::std::ptr::null_mut()
+                }
+            };
+            $crate::mem::forget(guard);
+            ret
+        }
+        Some(wrap::<$class>)
+    }}
+}
+
+
 #[macro_export]
 #[doc(hidden)]
 macro_rules! py_ssizearg_func {
@@ -180,7 +230,7 @@ macro_rules! py_ssizearg_func {
                 let py = $crate::Python::assume_gil_acquired();
                 let mut slf = $crate::Py::<T>::from_borrowed_ptr(py, slf);
 
-                let result = slf.$f(py, arg as isize).into();
+                let result = slf.as_mut().$f(py, arg as isize).into();
                 match result {
                     Ok(val) => {
                         <$conv as $crate::callback::CallbackConverter<$res_type>>
@@ -232,7 +282,7 @@ macro_rules! py_ternary_func{
 
                 let result = match arg1.extract() {
                     Ok(arg1) => match arg2.extract() {
-                        Ok(arg2) => slf.$f(py, arg1, arg2).into(),
+                        Ok(arg2) => slf.as_mut().$f(py, arg1, arg2).into(),
                         Err(e) => Err(e.into())
                     },
                     Err(e) => Err(e.into()),
@@ -268,6 +318,58 @@ macro_rules! py_ternary_func{
     }}
 }
 
+#[macro_export]
+#[doc(hidden)]
+macro_rules! py_ternary_self_func{
+    ($trait:ident, $class:ident :: $f:ident) => {{
+        #[allow(unused_mut)]
+        unsafe extern "C" fn wrap<T>(slf: *mut $crate::ffi::PyObject,
+                                     arg1: *mut $crate::ffi::PyObject,
+                                     arg2: *mut $crate::ffi::PyObject)
+                                     -> *mut $crate::ffi::PyObject
+            where T: for<'p> $trait<'p>
+        {
+            const LOCATION: &'static str = concat!(stringify!($class), ".", stringify!($f), "()");
+            let guard = $crate::callback::AbortOnDrop(LOCATION);
+            let ret = $crate::std::panic::catch_unwind(|| {
+                let py = $crate::Python::assume_gil_acquired();
+                let mut slf1 = $crate::Py::<T>::from_borrowed_ptr(py, slf);
+                let arg1 = $crate::PyObject::from_borrowed_ptr(py, arg1);
+                let arg2 = $crate::PyObject::from_borrowed_ptr(py, arg2);
+
+                let result = match arg1.extract() {
+                    Ok(arg1) => match arg2.extract() {
+                        Ok(arg2) => slf1.as_mut().$f(py, arg1, arg2).into(),
+                        Err(e) => Err(e.into())
+                    },
+                    Err(e) => Err(e.into()),
+                };
+
+                match result {
+                    Ok(_) => slf,
+                    Err(e) => {
+                        e.restore(py);
+                        $crate::std::ptr::null_mut()
+                    }
+                }
+            });
+
+            let ret = match ret {
+                Ok(r) => r,
+                Err(ref err) => {
+                    $crate::callback::handle_panic(
+                        $crate::Python::assume_gil_acquired(), err);
+                    $crate::std::ptr::null_mut()
+                }
+            };
+            $crate::mem::forget(guard);
+            ret
+        }
+
+         Some(wrap::<T>)
+    }}
+}
+
 
 #[macro_export]
 #[doc(hidden)]
@@ -336,7 +438,7 @@ macro_rules! py_func_del{
                     let name = PyObject::from_borrowed_ptr(py, name);
                     let result = match name.extract() {
                         Ok(name) =>
-                            slf.$f(py, name).into(),
+                            slf.as_mut().$f(py, name).into(),
                         Err(e) => Err(e.into()),
                     };
                     match result {
@@ -394,7 +496,7 @@ macro_rules! py_func_set_del{
                 if value.is_null() {
                     let result = match name.extract() {
                         Ok(name) =>
-                            slf.$f2(py, name).into(),
+                            slf.as_mut().$f2(py, name).into(),
                         Err(e) => Err(e.into()),
                     };
                     match result {
@@ -410,7 +512,7 @@ macro_rules! py_func_set_del{
                     let result = match name.extract() {
                         Ok(name) => match value.extract() {
                             Ok(value) => {
-                                slf.$f(py, name, value).into()
+                                slf.as_mut().$f(py, name, value).into()
                             },
                             Err(e) => Err(e.into()),
                         },
diff --git a/src/class/mapping.rs b/src/class/mapping.rs
index be1e6f12..c2357c42 100644
--- a/src/class/mapping.rs
+++ b/src/class/mapping.rs
@@ -23,10 +23,10 @@ pub trait PyMappingProtocol<'p>: PyTypeInfo + Sized + 'static {
     fn __getitem__(&'p self, py: Python<'p>, key: Self::Key)
                    -> Self::Result where Self: PyMappingGetItemProtocol<'p> {unimplemented!()}
 
-    fn __setitem__(&'p self, py: Python<'p>, key: Self::Key, value: Self::Value)
+    fn __setitem__(&'p mut self, py: Python<'p>, key: Self::Key, value: Self::Value)
                    -> Self::Result where Self: PyMappingSetItemProtocol<'p> {unimplemented!()}
 
-    fn __delitem__(&'p self, py: Python<'p>, key: Self::Key)
+    fn __delitem__(&'p mut self, py: Python<'p>, key: Self::Key)
                    -> Self::Result where Self: PyMappingDelItemProtocol<'p> {unimplemented!()}
 
     fn __iter__(&'p self, py: Python<'p>)
diff --git a/src/class/number.rs b/src/class/number.rs
index 9f05fb6d..9f82c615 100644
--- a/src/class/number.rs
+++ b/src/class/number.rs
@@ -74,31 +74,31 @@ pub trait PyNumberProtocol<'p>: PyTypeInfo {
     fn __ror__(&'p self, py: Python<'p>, other: Self::Other)
                -> Self::Result where Self: PyNumberROrProtocol<'p> { unimplemented!() }
 
-    fn __iadd__(&'p self, py: Python<'p>, other: Self::Other)
+    fn __iadd__(&'p mut self, py: Python<'p>, other: Self::Other)
                 -> Self::Result where Self: PyNumberIAddProtocol<'p> { unimplemented!() }
-    fn __isub__(&'p self, py: Python<'p>, other: Self::Other)
+    fn __isub__(&'p mut self, py: Python<'p>, other: Self::Other)
                 -> Self::Result where Self: PyNumberISubProtocol<'p> { unimplemented!() }
-    fn __imul__(&'p self, py: Python<'p>, other: Self::Other)
+    fn __imul__(&'p mut self, py: Python<'p>, other: Self::Other)
                 -> Self::Result where Self: PyNumberIMulProtocol<'p> { unimplemented!() }
-    fn __imatmul__(&'p self, py: Python<'p>, other: Self::Other)
+    fn __imatmul__(&'p mut self, py: Python<'p>, other: Self::Other)
                    -> Self::Result where Self: PyNumberIMatmulProtocol<'p> { unimplemented!() }
-    fn __itruediv__(&'p self, py: Python<'p>, other: Self::Other)
+    fn __itruediv__(&'p mut self, py: Python<'p>, other: Self::Other)
                     -> Self::Result where Self: PyNumberITruedivProtocol<'p> {unimplemented!()}
-    fn __ifloordiv__(&'p self, py: Python<'p>, other: Self::Other)
+    fn __ifloordiv__(&'p mut self, py: Python<'p>, other: Self::Other)
                      -> Self::Result where Self: PyNumberIFloordivProtocol<'p> {unimplemented!() }
-    fn __imod__(&'p self, py: Python<'p>, other: Self::Other)
+    fn __imod__(&'p mut self, py: Python<'p>, other: Self::Other)
                 -> Self::Result where Self: PyNumberIModProtocol<'p> { unimplemented!() }
-    fn __ipow__(&'p self, py: Python<'p>, other: Self::Other, modulo: Self::Modulo)
+    fn __ipow__(&'p mut self, py: Python<'p>, other: Self::Other, modulo: Self::Modulo)
                 -> Self::Result where Self: PyNumberIPowProtocol<'p> { unimplemented!() }
-    fn __ilshift__(&'p self, py: Python<'p>, other: Self::Other)
+    fn __ilshift__(&'p mut self, py: Python<'p>, other: Self::Other)
                    -> Self::Result where Self: PyNumberILShiftProtocol<'p> { unimplemented!() }
-    fn __irshift__(&'p self, py: Python<'p>, other: Self::Other)
+    fn __irshift__(&'p mut self, py: Python<'p>, other: Self::Other)
                    -> Self::Result where Self: PyNumberIRShiftProtocol<'p> { unimplemented!() }
-    fn __iand__(&'p self, py: Python<'p>, other: Self::Other)
+    fn __iand__(&'p mut self, py: Python<'p>, other: Self::Other)
                 -> Self::Result where Self: PyNumberIAndProtocol<'p> { unimplemented!() }
-    fn __ixor__(&'p self, py: Python<'p>, other: Self::Other)
+    fn __ixor__(&'p mut self, py: Python<'p>, other: Self::Other)
                 -> Self::Result where Self: PyNumberIXorProtocol<'p> { unimplemented!() }
-    fn __ior__(&'p self, py: Python<'p>, other: Self::Other)
+    fn __ior__(&'p mut self, py: Python<'p>, other: Self::Other)
                -> Self::Result where Self: PyNumberIOrProtocol<'p> { unimplemented!() }
 
     // Unary arithmetic
@@ -124,12 +124,12 @@ pub trait PyNumberProtocol<'p>: PyTypeInfo {
 
 
 pub trait PyNumberAddProtocol<'p>: PyNumberProtocol<'p> {
-    type Other: for<'a> FromPyObject<'a>;
+    type Other: FromPyObject<'p>;
     type Success: ToPyObject;
     type Result: Into<PyResult<Self::Success>>;
 }
 pub trait PyNumberSubProtocol<'p>: PyNumberProtocol<'p> {
-    type Other: for<'a> FromPyObject<'a>;
+    type Other: FromPyObject<'p>;
     type Success: ToPyObject;
     type Result: Into<PyResult<Self::Success>>;
 }
@@ -270,74 +270,60 @@ pub trait PyNumberROrProtocol<'p>: PyNumberProtocol<'p> {
 
 pub trait PyNumberIAddProtocol<'p>: PyNumberProtocol<'p> {
     type Other: FromPyObject<'p>;
-    type Success: ToPyObject;
-    type Result: Into<PyResult<Self::Success>>;
+    type Result: Into<PyResult<()>>;
 }
 pub trait PyNumberISubProtocol<'p>: PyNumberProtocol<'p> {
     type Other: FromPyObject<'p>;
-    type Success: ToPyObject;
-    type Result: Into<PyResult<Self::Success>>;
+    type Result: Into<PyResult<()>>;
 }
 pub trait PyNumberIMulProtocol<'p>: PyNumberProtocol<'p> {
     type Other: FromPyObject<'p>;
-    type Success: ToPyObject;
-    type Result: Into<PyResult<Self::Success>>;
+    type Result: Into<PyResult<()>>;
 }
 pub trait PyNumberIMatmulProtocol<'p>: PyNumberProtocol<'p> {
     type Other: FromPyObject<'p>;
-    type Success: ToPyObject;
-    type Result: Into<PyResult<Self::Success>>;
+    type Result: Into<PyResult<()>>;
 }
 pub trait PyNumberITruedivProtocol<'p>: PyNumberProtocol<'p> {
     type Other: FromPyObject<'p>;
-    type Success: ToPyObject;
-    type Result: Into<PyResult<Self::Success>>;
+    type Result: Into<PyResult<()>>;
 }
 pub trait PyNumberIFloordivProtocol<'p>: PyNumberProtocol<'p> {
     type Other: FromPyObject<'p>;
-    type Success: ToPyObject;
-    type Result: Into<PyResult<Self::Success>>;
+    type Result: Into<PyResult<()>>;
 }
 pub trait PyNumberIModProtocol<'p>: PyNumberProtocol<'p> {
     type Other: FromPyObject<'p>;
-    type Success: ToPyObject;
-    type Result: Into<PyResult<Self::Success>>;
+    type Result: Into<PyResult<()>>;
 }
 pub trait PyNumberIDivmodProtocol<'p>: PyNumberProtocol<'p> {
     type Other: FromPyObject<'p>;
-    type Success: ToPyObject;
-    type Result: Into<PyResult<Self::Success>>;
+    type Result: Into<PyResult<()>>;
 }
 pub trait PyNumberIPowProtocol<'p>: PyNumberProtocol<'p> {
     type Other: FromPyObject<'p>;
     type Modulo: FromPyObject<'p>;
-    type Success: ToPyObject;
-    type Result: Into<PyResult<Self::Success>>;
+    type Result: Into<PyResult<()>>;
 }
 pub trait PyNumberILShiftProtocol<'p>: PyNumberProtocol<'p> {
     type Other: FromPyObject<'p>;
-    type Success: ToPyObject;
-    type Result: Into<PyResult<Self::Success>>;
+    type Result: Into<PyResult<()>>;
 }
 pub trait PyNumberIRShiftProtocol<'p>: PyNumberProtocol<'p> {
     type Other: FromPyObject<'p>;
-    type Success: ToPyObject;
-    type Result: Into<PyResult<Self::Success>>;
+    type Result: Into<PyResult<()>>;
 }
 pub trait PyNumberIAndProtocol<'p>: PyNumberProtocol<'p> {
     type Other: FromPyObject<'p>;
-    type Success: ToPyObject;
-    type Result: Into<PyResult<Self::Success>>;
+    type Result: Into<PyResult<()>>;
 }
 pub trait PyNumberIXorProtocol<'p>: PyNumberProtocol<'p> {
     type Other: FromPyObject<'p>;
-    type Success: ToPyObject;
-    type Result: Into<PyResult<Self::Success>>;
+    type Result: Into<PyResult<()>>;
 }
 pub trait PyNumberIOrProtocol<'p>: PyNumberProtocol<'p> {
     type Other: FromPyObject<'p>;
-    type Success: ToPyObject;
-    type Result: Into<PyResult<Self::Success>>;
+    type Result: Into<PyResult<()>>;
 }
 
 pub trait PyNumberNegProtocol<'p>: PyNumberProtocol<'p> {
@@ -689,8 +675,7 @@ impl<'p, T> PyNumberIAddProtocolImpl for T where T: PyNumberProtocol<'p> {
 }
 impl<T> PyNumberIAddProtocolImpl for T where T: for<'p> PyNumberIAddProtocol<'p> {
     fn nb_inplace_add() -> Option<ffi::binaryfunc> {
-        py_binary_func!(PyNumberIAddProtocol,
-                        T::__iadd__, T::Success, PyObjectCallbackConverter)
+        py_binary_self_func!(PyNumberIAddProtocol, T::__iadd__)
     }
 }
 
@@ -702,8 +687,7 @@ impl<'p, T> PyNumberISubProtocolImpl for T where T: PyNumberProtocol<'p> {
 }
 impl<T> PyNumberISubProtocolImpl for T where T: for<'p> PyNumberISubProtocol<'p> {
     fn nb_inplace_subtract() -> Option<ffi::binaryfunc> {
-        py_binary_func!(PyNumberISubProtocol,
-                        T::__isub__, T::Success, PyObjectCallbackConverter)
+        py_binary_self_func!(PyNumberISubProtocol, T::__isub__)
     }
 }
 
@@ -715,8 +699,7 @@ impl<'p, T> PyNumberIMulProtocolImpl for T where T: PyNumberProtocol<'p> {
 }
 impl<T> PyNumberIMulProtocolImpl for T where T: for<'p> PyNumberIMulProtocol<'p> {
     fn nb_inplace_multiply() -> Option<ffi::binaryfunc> {
-        py_binary_func!(PyNumberIMulProtocol,
-                        T::__imul__, T::Success, PyObjectCallbackConverter)
+        py_binary_self_func!(PyNumberIMulProtocol, T::__imul__)
     }
 }
 
@@ -728,8 +711,7 @@ impl<'p, T> PyNumberIMatmulProtocolImpl for T where T: PyNumberProtocol<'p> {
 }
 impl<T> PyNumberIMatmulProtocolImpl for T where T: for<'p> PyNumberIMatmulProtocol<'p> {
     fn nb_inplace_matrix_multiply() -> Option<ffi::binaryfunc> {
-        py_binary_func!(PyNumberIMatmulProtocol,
-                        T::__imatmul__, T::Success, PyObjectCallbackConverter)
+        py_binary_self_func!(PyNumberIMatmulProtocol, T::__imatmul__)
     }
 }
 
@@ -741,8 +723,7 @@ impl<'p, T> PyNumberITruedivProtocolImpl for T where T: PyNumberProtocol<'p> {
 }
 impl<T> PyNumberITruedivProtocolImpl for T where T: for<'p> PyNumberITruedivProtocol<'p> {
     fn nb_inplace_true_divide() -> Option<ffi::binaryfunc> {
-        py_binary_func!(PyNumberITruedivProtocol,
-                        T::__itruediv__, T::Success, PyObjectCallbackConverter)
+        py_binary_self_func!(PyNumberITruedivProtocol, T::__itruediv__)
     }
 }
 
@@ -754,8 +735,7 @@ impl<'p, T> PyNumberIFloordivProtocolImpl for T where T: PyNumberProtocol<'p> {
 }
 impl<T> PyNumberIFloordivProtocolImpl for T where T: for<'p> PyNumberIFloordivProtocol<'p> {
     fn nb_inplace_floor_divide() -> Option<ffi::binaryfunc> {
-        py_binary_func!(PyNumberIFloordivProtocol,
-                        T::__ifloordiv__, T::Success, PyObjectCallbackConverter)
+        py_binary_self_func!(PyNumberIFloordivProtocol, T::__ifloordiv__)
     }
 }
 
@@ -767,8 +747,7 @@ impl<'p, T> PyNumberIModProtocolImpl for T where T: PyNumberProtocol<'p> {
 }
 impl<T> PyNumberIModProtocolImpl for T where T: for<'p> PyNumberIModProtocol<'p> {
     fn nb_inplace_remainder() -> Option<ffi::binaryfunc> {
-        py_binary_func!(PyNumberIModProtocol,
-                        T::__imod__, T::Success, PyObjectCallbackConverter)
+        py_binary_self_func!(PyNumberIModProtocol, T::__imod__)
     }
 }
 
@@ -780,8 +759,7 @@ impl<'p, T> PyNumberIPowProtocolImpl for T where T: PyNumberProtocol<'p> {
 }
 impl<T> PyNumberIPowProtocolImpl for T where T: for<'p> PyNumberIPowProtocol<'p> {
     fn nb_inplace_power() -> Option<ffi::ternaryfunc> {
-        py_ternary_func!(PyNumberIPowProtocol,
-                         T::__ipow__, T::Success, PyObjectCallbackConverter)
+        py_ternary_self_func!(PyNumberIPowProtocol, T::__ipow__)
     }
 }
 
@@ -793,8 +771,7 @@ impl<'p, T> PyNumberILShiftProtocolImpl for T where T: PyNumberProtocol<'p> {
 }
 impl<T> PyNumberILShiftProtocolImpl for T where T: for<'p> PyNumberILShiftProtocol<'p> {
     fn nb_inplace_lshift() -> Option<ffi::binaryfunc> {
-        py_binary_func!(PyNumberILShiftProtocol,
-                        T::__ilshift__, T::Success, PyObjectCallbackConverter)
+        py_binary_self_func!(PyNumberILShiftProtocol, T::__ilshift__)
     }
 }
 
@@ -806,8 +783,7 @@ impl<'p, T> PyNumberIRShiftProtocolImpl for T where T: PyNumberProtocol<'p> {
 }
 impl<T> PyNumberIRShiftProtocolImpl for T where T: for<'p> PyNumberIRShiftProtocol<'p> {
     fn nb_inplace_rshift() -> Option<ffi::binaryfunc> {
-        py_binary_func!(PyNumberIRShiftProtocol,
-                        T::__irshift__, T::Success, PyObjectCallbackConverter)
+        py_binary_self_func!(PyNumberIRShiftProtocol, T::__irshift__)
     }
 }
 
@@ -820,8 +796,7 @@ impl<'p, T> PyNumberIAndProtocolImpl for T where T: PyNumberProtocol<'p> {
 }
 impl<T> PyNumberIAndProtocolImpl for T where T: for<'p> PyNumberIAndProtocol<'p> {
     fn nb_inplace_and() -> Option<ffi::binaryfunc> {
-        py_binary_func!(PyNumberIAndProtocol,
-                        T::__iand__, T::Success, PyObjectCallbackConverter)
+        py_binary_self_func!(PyNumberIAndProtocol, T::__iand__)
     }
 }
 
@@ -833,8 +808,7 @@ impl<'p, T> PyNumberIXorProtocolImpl for T where T: PyNumberProtocol<'p> {
 }
 impl<T> PyNumberIXorProtocolImpl for T where T: for<'p> PyNumberIXorProtocol<'p> {
     fn nb_inplace_xor() -> Option<ffi::binaryfunc> {
-        py_binary_func!(PyNumberIXorProtocol,
-                        T::__ixor__, T::Success, PyObjectCallbackConverter)
+        py_binary_self_func!(PyNumberIXorProtocol, T::__ixor__)
     }
 }
 
@@ -846,8 +820,7 @@ impl<'p, T> PyNumberIOrProtocolImpl for T where T: PyNumberProtocol<'p> {
 }
 impl<T> PyNumberIOrProtocolImpl for T where T: for<'p> PyNumberIOrProtocol<'p> {
     fn nb_inplace_or() -> Option<ffi::binaryfunc> {
-        py_binary_func!(PyNumberIOrProtocol,
-                        T::__ior__, T::Success, PyObjectCallbackConverter)
+        py_binary_self_func!(PyNumberIOrProtocol, T::__ior__)
     }
 }
 
diff --git a/src/class/sequence.rs b/src/class/sequence.rs
index 4ba52da0..b41b92ea 100644
--- a/src/class/sequence.rs
+++ b/src/class/sequence.rs
@@ -23,10 +23,10 @@ pub trait PySequenceProtocol<'p>: PyTypeInfo + Sized + 'static {
     fn __getitem__(&'p self, py: Python<'p>, key: isize) -> Self::Result
         where Self: PySequenceGetItemProtocol<'p> { unimplemented!() }
 
-    fn __setitem__(&'p self, py: Python<'p>, key: isize, value: Self::Value) -> Self::Result
+    fn __setitem__(&'p mut self, py: Python<'p>, key: isize, value: Self::Value) -> Self::Result
         where Self: PySequenceSetItemProtocol<'p> { unimplemented!() }
 
-    fn __delitem__(&'p self, py: Python<'p>, key: isize) -> Self::Result
+    fn __delitem__(&'p mut self, py: Python<'p>, key: isize) -> Self::Result
         where Self: PySequenceDelItemProtocol<'p> { unimplemented!() }
 
     fn __contains__(&'p self, py: Python<'p>, item: Self::Item) -> Self::Result
@@ -38,10 +38,10 @@ pub trait PySequenceProtocol<'p>: PyTypeInfo + Sized + 'static {
     fn __repeat__(&'p self, py: Python<'p>, count: isize) -> Self::Result
         where Self: PySequenceRepeatProtocol<'p> { unimplemented!() }
 
-    fn __inplace_concat__(&'p self, py: Python<'p>, other: Self::Other) -> Self::Result
+    fn __inplace_concat__(&'p mut self, py: Python<'p>, other: Self::Other) -> Self::Result
         where Self: PySequenceInplaceConcatProtocol<'p> { unimplemented!() }
 
-    fn __inplace_repeat__(&'p self, py: Python<'p>, count: isize) -> Self::Result
+    fn __inplace_repeat__(&'p mut self, py: Python<'p>, count: isize) -> Self::Result
         where Self: PySequenceInplaceRepeatProtocol<'p> { unimplemented!() }
 }
 
diff --git a/src/conversion.rs b/src/conversion.rs
index 3e56b521..8cf4790d 100644
--- a/src/conversion.rs
+++ b/src/conversion.rs
@@ -32,7 +32,6 @@ pub trait IntoPyObject {
     #[inline]
     fn into_object<'p>(self, py: Python<'p>) -> Py<'p, PyObject>
         where Self: Sized;
-
 }
 
 
@@ -100,7 +99,7 @@ impl <'p, T: ?Sized> RefFromPyObject<'p> for T
 }
 
 // Default IntoPyObject implementation
-impl <T> IntoPyObject for T where T: ToPyObject
+impl<T> IntoPyObject for T where T: ToPyObject
 {
     #[inline]
     default fn into_object<'p>(self, py: Python<'p>) -> Py<'p, PyObject> where Self: Sized
@@ -139,7 +138,7 @@ impl <T> ToPyObject for Option<T> where T: ToPyObject {
     }
 }
 
-impl <T> IntoPyObject for Option<T> where T: IntoPyObject {
+impl<T> IntoPyObject for Option<T> where T: IntoPyObject {
 
     fn into_object<'p>(self, py: Python<'p>) -> Py<'p, PyObject> {
         match self {
diff --git a/src/lib.rs b/src/lib.rs
index e7194afc..f229820a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -69,9 +69,9 @@ pub use pyptr::{Py, PyPtr};
 
 pub use err::{PyErr, PyResult, PyDowncastError};
 pub use objects::*;
-pub use python::{AsPy, Python};
+pub use python::{AsPy, Python, PythonToken};
 pub use pythonrun::{GILGuard, GILProtected, prepare_freethreaded_python};
-pub use conversion::{FromPyObject, /*RefFromPyObject,*/ ToPyObject, IntoPyObject, ToPyTuple};
+pub use conversion::{FromPyObject, RefFromPyObject, ToPyObject, IntoPyObject, ToPyTuple};
 pub use class::{CompareOp};
 pub mod class;
 pub use class::*;
diff --git a/src/objectprotocol.rs b/src/objectprotocol.rs
index 21fe2fdb..e9e662e5 100644
--- a/src/objectprotocol.rs
+++ b/src/objectprotocol.rs
@@ -1,20 +1,6 @@
-// Copyright (c) 2015 Daniel Grunwald
+// Copyright (c) 2017-present PyO3 Project and Contributors
 //
-// Permission is hereby granted, free of charge, to any person obtaining a copy of this
-// software and associated documentation files (the "Software"), to deal in the Software
-// without restriction, including without limitation the rights to use, copy, modify, merge,
-// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
-// to whom the Software is furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in all copies or
-// substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
-// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
-// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
-// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
-// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
-// DEALINGS IN THE SOFTWARE.
+// based on Daniel Grunwald's https://github.com/dgrunwald/rust-cpython
 
 use std::fmt;
 use std::cmp::Ordering;
@@ -303,7 +289,6 @@ impl<T> fmt::Display for PyPtr<T> {
     }
 }
 
-
 #[cfg(test)]
 mod test {
     use std;
diff --git a/src/objects/mod.rs b/src/objects/mod.rs
index 2b63f003..a80e696d 100644
--- a/src/objects/mod.rs
+++ b/src/objects/mod.rs
@@ -22,22 +22,22 @@ macro_rules! pyobject_newtype(
 
         impl<'p> $crate::python::AsPy<'p> for &'p $name {
             #[inline]
-            fn py<'a>(&'a self) -> Python<'p> {
+            fn py<'a>(&'a self) -> $crate::Python<'p> {
                 unsafe { $crate::python::Python::assume_gil_acquired() }
             }
         }
 
         impl $crate::python::ToPythonPointer for $name {
             #[inline]
-            fn as_ptr(&self) -> *mut ffi::PyObject {
-                self as *const _ as *mut ffi::PyObject
+            fn as_ptr(&self) -> *mut $crate::ffi::PyObject {
+                self as *const _ as *mut $crate::ffi::PyObject
             }
         }
 
         impl<'a> $crate::python::ToPythonPointer for &'a $name {
             #[inline]
-            fn as_ptr(&self) -> *mut ffi::PyObject {
-                self as *const _ as *mut ffi::PyObject
+            fn as_ptr(&self) -> *mut $crate::ffi::PyObject {
+                self as *const _ as *mut $crate::ffi::PyObject
             }
         }
 
@@ -63,6 +63,32 @@ macro_rules! pyobject_newtype(
                 unsafe { &mut $crate::ffi::$typeobject }
             }
         }
+
+        impl $crate::std::fmt::Debug for $name {
+            default fn fmt(&self, f: &mut $crate::std::fmt::Formatter)
+                           -> Result<(), $crate::std::fmt::Error>
+            {
+                let py = unsafe { $crate::python::Python::assume_gil_acquired() };
+                let s = unsafe { $crate::Py::<$crate::PyString>::cast_from_owned_nullptr(
+                    py, $crate::ffi::PyObject_Repr(
+                        $crate::python::ToPythonPointer::as_ptr(self))) };
+                let repr_obj = try!(s.map_err(|_| $crate::std::fmt::Error));
+                f.write_str(&repr_obj.to_string_lossy())
+            }
+        }
+
+        impl $crate::std::fmt::Display for $name {
+            fn fmt(&self, f: &mut $crate::std::fmt::Formatter)
+                   -> Result<(), $crate::std::fmt::Error>
+            {
+                let py = unsafe { $crate::python::Python::assume_gil_acquired() };
+                let s = unsafe { $crate::Py::<$crate::PyString>::cast_from_owned_nullptr(
+                    py, $crate::ffi::PyObject_Str(
+                        $crate::python::ToPythonPointer::as_ptr(self))) };
+                let str_obj = try!(s.map_err(|_| $crate::std::fmt::Error));
+                f.write_str(&str_obj.to_string_lossy())
+            }
+        }
     );
 );
 
diff --git a/src/pyptr.rs b/src/pyptr.rs
index c09c8c84..d4d32859 100644
--- a/src/pyptr.rs
+++ b/src/pyptr.rs
@@ -20,6 +20,26 @@ pub struct PyPtr<T> {
 }
 
 impl<T> PyPtr<T> {
+    /// Creates a PyPtr instance for the given FFI pointer.
+    /// This moves ownership over the pointer into the Py.
+    /// Undefined behavior if the pointer is NULL or invalid.
+    #[inline]
+    pub unsafe fn from_owned_ptr(ptr: *mut ffi::PyObject) -> PyPtr<T> {
+        debug_assert!(!ptr.is_null() && ffi::Py_REFCNT(ptr) > 0);
+        PyPtr {inner: ptr, _t: PhantomData}
+    }
+
+    /// Creates a PyPTr instance for the given FFI pointer.
+    /// Calls Py_INCREF() on the ptr.
+    /// Undefined behavior if the pointer is NULL or invalid.
+    /// Caller of this method has to have valid Py object.
+    #[inline]
+    pub unsafe fn from_borrowed_ptr(ptr: *mut ffi::PyObject) -> PyPtr<T> {
+        debug_assert!(!ptr.is_null() && ffi::Py_REFCNT(ptr) > 0);
+        ffi::Py_INCREF(ptr);
+        PyPtr {inner: ptr, _t: PhantomData}
+    }
+
     pub fn as_ref<'p>(&self, _py: Python<'p>) -> Py<'p, T> {
         Py{inner: self.inner, _t: PhantomData, _py: PhantomData}
     }
@@ -56,7 +76,6 @@ impl<T> IntoPythonPointer for PyPtr<T> {
     #[inline]
     #[must_use]
     fn into_ptr(self) -> *mut ffi::PyObject {
-        println!("INTO PTR: {:?}", self.inner);
         let ptr = self.inner;
         std::mem::forget(self);
         ptr
@@ -206,7 +225,7 @@ impl<'p, T> Py<'p, T>
 impl<'p, T> Py<'p, T> where T: PyTypeInfo
 {
     /// Create new python object and move T instance under python management
-    pub fn new(py: &Python<'p>, value: T) -> PyResult<Py<'p, T>> where T: PyObjectAlloc<Type=T>
+    pub fn new(py: Python<'p>, value: T) -> PyResult<Py<'p, T>> where T: PyObjectAlloc<Type=T>
     {
         let ob = unsafe {
             try!(<T as PyObjectAlloc>::alloc(py, value))
@@ -463,10 +482,10 @@ impl <'a, T> ToPyObject for Py<'a, T> {
     }
 }
 
-impl <'a, T> IntoPyObject for Py<'a, T> {
+impl<'p, T> IntoPyObject for Py<'p, T> {
 
     #[inline]
-    default fn into_object<'p>(self, py: Python<'p>) -> Py<'p, PyObject> {
+    default fn into_object<'a>(self, py: Python<'a>) -> Py<'a, PyObject> {
         PyObject::from_borrowed_ptr(py, self.inner)
     }
 }
diff --git a/src/python.rs b/src/python.rs
index fa9562e0..b35a05d0 100644
--- a/src/python.rs
+++ b/src/python.rs
@@ -1,20 +1,6 @@
-// Copyright (c) 2015 Daniel Grunwald
+// Copyright (c) 2017-present PyO3 Project and Contributors
 //
-// Permission is hereby granted, free of charge, to any person obtaining a copy of this
-// software and associated documentation files (the "Software"), to deal in the Software
-// without restriction, including without limitation the rights to use, copy, modify, merge,
-// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
-// to whom the Software is furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in all copies or
-// substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
-// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
-// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
-// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
-// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
-// DEALINGS IN THE SOFTWARE.
+// based on Daniel Grunwald's https://github.com/dgrunwald/rust-cpython
 
 use std;
 use std::ffi::CString;
@@ -42,11 +28,19 @@ use pythonrun::GILGuard;
 #[derive(Copy, Clone)]
 pub struct Python<'p>(PhantomData<&'p GILGuard>);
 
+pub struct PythonToken<T>(PhantomData<T>);
+
 
 pub trait AsPy<'p> {
     fn py<'a>(&'a self) -> Python<'p>;
 }
 
+
+pub trait PyClone : Sized {
+    fn clone_ref(&self) -> PyPtr<Self>;
+}
+
+
 /// This trait allows retrieving the underlying FFI pointer from Python objects.
 pub trait ToPythonPointer {
     /// Retrieves the underlying FFI pointer (as a borrowed pointer).
@@ -55,7 +49,8 @@ pub trait ToPythonPointer {
 
 /// This trait allows retrieving the underlying FFI pointer from Python objects.
 pub trait IntoPythonPointer {
-    /// Retrieves the underlying FFI pointer (as a borrowed pointer).
+    /// Retrieves the underlying FFI pointer. Whether pointer owned or borrowed
+    /// depends on implementation.
     fn into_ptr(self) -> *mut ffi::PyObject;
 }
 
@@ -82,6 +77,7 @@ impl <T> IntoPythonPointer for Option<T> where T: IntoPythonPointer {
     }
 }
 
+
 impl<'p> Python<'p> {
     /// Retrieve Python instance under the assumption that the GIL is already acquired at this point,
     /// and stays acquired for the lifetime `'p`.
@@ -169,14 +165,6 @@ impl<'p> Python<'p> {
         }
     }
 
-    /// Create new PyObject instance
-    #[inline]
-    pub fn init<T>(&'p self, value: T) -> Py<'p, T>
-        where T: PyTypeInfo + PyObjectAlloc<Type=T>
-    {
-        Py::new(self, value).unwrap()
-    }
-
     /// Gets the Python builtin value `None`.
     #[allow(non_snake_case)] // the Python keyword starts with uppercase
     #[inline]
@@ -219,8 +207,69 @@ impl<'p> Python<'p> {
     pub fn import(self, name : &str) -> PyResult<Py<'p, PyModule>> {
         PyModule::import(self, name)
     }
+
+    pub fn with_token<T, F>(self, f: F) -> Py<'p, T>
+        where F: FnOnce(PythonToken<T>) -> T,
+              T: PyTypeInfo + PyObjectAlloc<Type=T>
+    {
+        let value = f(PythonToken(PhantomData));
+        Py::new(self, value).unwrap()
+    }
 }
 
+impl<T> PythonToken<T> {
+
+    /// Gets the Python builtin value `None`.
+    #[allow(non_snake_case)] // the Python keyword starts with uppercase
+    #[inline]
+    pub fn None(self) -> PyPtr<PyObject> {
+        unsafe { PyPtr::from_borrowed_ptr(ffi::Py_None()) }
+    }
+
+    /// Gets the Python builtin value `True`.
+    #[allow(non_snake_case)] // the Python keyword starts with uppercase
+    #[inline]
+    pub fn True(self) -> PyPtr<PyBool> {
+        unsafe { PyPtr::from_borrowed_ptr(ffi::Py_True()) }
+    }
+
+    /// Gets the Python builtin value `False`.
+    #[allow(non_snake_case)] // the Python keyword starts with uppercase
+    #[inline]
+    pub fn False(self) -> PyPtr<PyBool> {
+        unsafe { PyPtr::from_borrowed_ptr(ffi::Py_False()) }
+    }
+
+    /// Gets the Python builtin value `NotImplemented`.
+    #[allow(non_snake_case)] // the Python keyword starts with uppercase
+    #[inline]
+    pub fn NotImplemented(self) -> PyPtr<PyObject> {
+        unsafe { PyPtr::from_borrowed_ptr(ffi::Py_NotImplemented()) }
+    }
+
+    /// Gets the Python type object for type T.
+    pub fn get_type<U>(self) -> PyPtr<PyType> where U: PyTypeObject {
+        U::type_object(Python(PhantomData)).into_pptr()
+    }
+
+    /// Execute closure `F` with Python instance.
+    /// Retrieve Python instance under the assumption that the GIL is already acquired
+    /// at this point, and stays acquired during closure call.
+    pub fn with_py<'p, F>(self, f: F) where F: FnOnce(Python<'p>)
+    {
+        f(Python(PhantomData))
+    }
+
+    pub fn with_token<P, F>(self, f: F) -> PyPtr<P>
+        where F: FnOnce(PythonToken<P>) -> P,
+              P: PyTypeInfo + PyObjectAlloc<Type=P>
+    {
+        let value = f(PythonToken(PhantomData));
+        Py::new(Python(PhantomData), value).unwrap().into_pptr()
+    }
+}
+
+
 #[cfg(test)]
 mod test {
     use {Python, PyDict};
diff --git a/src/typeob.rs b/src/typeob.rs
index 681051ec..4681624d 100644
--- a/src/typeob.rs
+++ b/src/typeob.rs
@@ -92,12 +92,12 @@ pub trait PyObjectAlloc {
     /// and initializes it using init_val.
     /// `ty` must be derived from the Self type, and the resulting object
     /// must be of type `ty`.
-    unsafe fn alloc(_py: &Python, value: Self::Type) -> PyResult<*mut ffi::PyObject>;
+    unsafe fn alloc(_py: Python, value: Self::Type) -> PyResult<*mut ffi::PyObject>;
 
     /// Calls the rust destructor for the object and frees the memory
     /// (usually by calling ptr->ob_type->tp_free).
     /// This function is used as tp_dealloc implementation.
-    unsafe fn dealloc(_py: &Python, obj: *mut ffi::PyObject);
+    unsafe fn dealloc(_py: Python, obj: *mut ffi::PyObject);
 }
 
 /// A PythonObject that is usable as a base type for #[class]
@@ -108,7 +108,7 @@ impl<T> PyObjectAlloc for T where T : PyTypeInfo {
     /// and initializes it using init_val.
     /// `ty` must be derived from the Self type, and the resulting object
     /// must be of type `ty`.
-    unsafe fn alloc(_py: &Python, value: T::Type) -> PyResult<*mut ffi::PyObject> {
+    unsafe fn alloc(_py: Python, value: T::Type) -> PyResult<*mut ffi::PyObject> {
         let obj = ffi::PyType_GenericAlloc(
             <Self as PyTypeInfo>::type_object(), 0);
 
@@ -122,7 +122,7 @@ impl<T> PyObjectAlloc for T where T : PyTypeInfo {
     /// Calls the rust destructor for the object and frees the memory
     /// (usually by calling ptr->ob_type->tp_free).
     /// This function is used as tp_dealloc implementation.
-    unsafe fn dealloc(_py: &Python, obj: *mut ffi::PyObject) {
+    unsafe fn dealloc(_py: Python, obj: *mut ffi::PyObject) {
         let ptr = (obj as *mut u8).offset(
             <Self as PyTypeInfo>::offset() as isize) as *mut Self::Type;
         std::ptr::drop_in_place(ptr);
@@ -296,7 +296,7 @@ unsafe extern "C" fn tp_dealloc_callback<T>(obj: *mut ffi::PyObject)
     println!("DEALLOC: {:?}", obj);
     let guard = AbortOnDrop("Cannot unwind out of tp_dealloc");
     let py = Python::assume_gil_acquired();
-    let r = <T as PyObjectAlloc>::dealloc(&py, obj);
+    let r = <T as PyObjectAlloc>::dealloc(py, obj);
     mem::forget(guard);
     r
 }
@@ -329,24 +329,24 @@ fn py_class_method_defs<T>() -> (Option<ffi::newfunc>,
         }
     }
 
-    for def in <T as class::basic::PyObjectProtocolImpl>::methods() {
-        defs.push(def.as_method_def())
-    }
-    for def in <T as class::async::PyAsyncProtocolImpl>::methods() {
-        defs.push(def.as_method_def())
-    }
-    for def in <T as class::context::PyContextProtocolImpl>::methods() {
-        defs.push(def.as_method_def())
-    }
-    for def in <T as class::mapping::PyMappingProtocolImpl>::methods() {
-        defs.push(def.as_method_def())
-    }
-    for def in <T as class::number::PyNumberProtocolImpl>::methods() {
-        defs.push(def.as_method_def())
-    }
-    for def in <T as class::descr::PyDescrProtocolImpl>::methods() {
-        defs.push(def.as_method_def())
-    }
+    //for def in <T as class::basic::PyObjectProtocolImpl>::methods() {
+    //    defs.push(def.as_method_def())
+    //}
+    //for def in <T as class::async::PyAsyncProtocolImpl>::methods() {
+    //    defs.push(def.as_method_def())
+    //}
+    //for def in <T as class::context::PyContextProtocolImpl>::methods() {
+    //    defs.push(def.as_method_def())
+    //}
+    //for def in <T as class::mapping::PyMappingProtocolImpl>::methods() {
+    //defs.push(def.as_method_def())
+    //}
+    //for def in <T as class::number::PyNumberProtocolImpl>::methods() {
+    //    defs.push(def.as_method_def())
+    //}
+    //for def in <T as class::descr::PyDescrProtocolImpl>::methods() {
+    //    defs.push(def.as_method_def())
+    //}
 
     (new, call, defs)
 }
diff --git a/tests/test_class.rs b/tests/test_class.rs
index cdfa74e4..b8b0ed51 100644
--- a/tests/test_class.rs
+++ b/tests/test_class.rs
@@ -9,6 +9,8 @@ use std::cell::RefCell;
 use std::sync::Arc;
 use std::sync::atomic::{AtomicBool, Ordering};
 use pyo3::ffi;
+use pyo3::python::ToPythonPointer;
+
 
 macro_rules! py_run {
     ($py:expr, $val:ident, $code:expr) => {{
@@ -26,7 +28,7 @@ macro_rules! py_assert {
 macro_rules! py_expect_exception {
     ($py:expr, $val:ident, $code:expr, $err:ident) => {{
         let d = PyDict::new($py);
-        d.set_item($py, stringify!($val), &$val).unwrap();
+        d.set_item(stringify!($val), &$val).unwrap();
         let res = $py.run($code, None, Some(&d));
         let err = res.unwrap_err();
         if !err.matches($py, $py.get_type::<exc::$err>()) {
@@ -71,7 +73,7 @@ struct EmptyClassWithNew { }
 #[py::methods]
 impl EmptyClassWithNew {
     #[__new__]
-    fn __new__(cls: &PyType) -> PyResult<EmptyClassWithNew> {
+    fn __new__(cls: &PyType, py: Python) -> PyResult<EmptyClassWithNew> {
         Ok(EmptyClassWithNew{})
     }
 }
@@ -91,7 +93,7 @@ struct NewWithOneArg {
 #[py::methods]
 impl NewWithOneArg {
     #[new]
-    fn __new__(_cls: &PyType, arg: i32) -> PyResult<NewWithOneArg> {
+    fn __new__(_cls: &PyType, py: Python, arg: i32) -> PyResult<NewWithOneArg> {
         Ok(NewWithOneArg{_data: arg})
     }
 }
@@ -114,7 +116,7 @@ struct NewWithTwoArgs {
 #[py::methods]
 impl NewWithTwoArgs {
     #[new]
-    fn __new__(_cls: &PyType, arg1: i32, arg2: i32) -> PyResult<NewWithTwoArgs> {
+    fn __new__(_cls: &PyType, py: Python, arg1: i32, arg2: i32) -> PyResult<NewWithTwoArgs> {
         Ok(NewWithTwoArgs{_data1: arg1, _data2: arg2})
     }
 }
@@ -169,7 +171,7 @@ struct InstanceMethod {
 
 #[py::methods]
 impl InstanceMethod {
-    fn method(&self) -> PyResult<i32> {
+    fn method(&self, py: Python) -> PyResult<i32> {
         Ok(self.member)
     }
 }
@@ -180,7 +182,7 @@ fn instance_method() {
     let py = gil.python();
 
     let obj = py.init(InstanceMethod{member: 42});
-    assert!(obj.method().unwrap() == 42);
+    assert!(obj.method(py).unwrap() == 42);
     let d = PyDict::new(py);
     d.set_item("obj", obj).unwrap();
     py.run("assert obj.method() == 42", None, Some(&d)).unwrap();
@@ -192,7 +194,7 @@ struct InstanceMethodWithArgs {
 }
 #[py::methods]
 impl InstanceMethodWithArgs {
-    fn method(&self, multiplier: i32) -> PyResult<i32> {
+    fn method(&self, py: Python, multiplier: i32) -> PyResult<i32> {
         Ok(self.member * multiplier)
     }
 }
@@ -203,7 +205,7 @@ fn instance_method_with_args() {
     let py = gil.python();
 
     let obj = py.init(InstanceMethodWithArgs{member: 7});
-    assert!(obj.method(6).unwrap() == 42);
+    assert!(obj.method(py, 6).unwrap() == 42);
     let d = PyDict::new(py);
     d.set_item("obj", obj).unwrap();
     py.run("assert obj.method(3) == 21", None, Some(&d)).unwrap();
@@ -261,7 +263,7 @@ struct StaticMethod {}
 impl StaticMethod {
     #[new]
     fn __new__(cls: &PyType, py: Python) -> PyResult<StaticMethod> {
-        StaticMethod::create_instance(py)
+        Ok(StaticMethod{}.into_object(py))
     }
 
     //#[staticmethod]
@@ -303,18 +305,18 @@ impl StaticMethod {
 
 #[py::class]
 struct GCIntegration {
-    self_ref: RefCell<PyObject>,
+    self_ref: RefCell<PyPtr<PyObject>>,
     dropped: TestDropCall,
 }
 
 #[py::proto]
 impl PyGCProtocol for GCIntegration {
     fn __traverse__(&self, py: Python, visit: PyVisit) -> Result<(), PyTraverseError> {
-        visit.call(&*self.self_ref(py).borrow())
+        visit.call(&*self.self_ref.borrow())
     }
 
-    fn __clear__(&self, py: Python) {
-        let old_ref = mem::replace(&mut *self.self_ref(py).borrow_mut(), py.None());
+    fn __clear__(&mut self, py: Python) {
+        let old_ref = mem::replace(&mut *self.self_ref.borrow_mut(), py.None());
         // Release reference only after the mutable borrow has expired.
         old_ref.release_ref(py);
     }
@@ -326,12 +328,12 @@ fn gc_integration() {
     let py = gil.python();
 
     let drop_called = Arc::new(AtomicBool::new(false));
-    let inst = GCIntegration::create_instance(py,
-        RefCell::new(py.None()),
-        TestDropCall { drop_called: drop_called.clone() }
-    ).unwrap();
-    *inst.self_ref(py).borrow_mut() = inst.as_object().clone_ref(py);
-    inst.release_ref(py);
+    let inst = py.init(GCIntegration{
+        self_ref: RefCell::new(py.None()),
+        dropped: TestDropCall { drop_called: drop_called.clone() }});
+
+    *inst.self_ref.borrow_mut() = inst.clone_ref().into_object().into_pptr();
+    drop(inst);
 
     py.run("import gc; gc.collect()", None, None).unwrap();
     assert!(drop_called.load(Ordering::Relaxed));
@@ -345,7 +347,7 @@ pub struct Len {
 #[py::proto]
 impl PyMappingProtocol for Len {
     fn __len__(&self, py: Python) -> PyResult<usize> {
-        Ok(*self.l(py))
+        Ok(self.l)
     }
 }
 
@@ -354,14 +356,14 @@ fn len() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let inst = Len::create_instance(py, 10).unwrap();
+    let inst = Len{l: 10}.into_object(py);
     py_assert!(py, inst, "len(inst) == 10");
     unsafe {
-        assert_eq!(ffi::PyObject_Size(inst.as_object().as_ptr()), 10);
-        assert_eq!(ffi::PyMapping_Size(inst.as_object().as_ptr()), 10);
+        assert_eq!(ffi::PyObject_Size(inst.as_ptr()), 10);
+        assert_eq!(ffi::PyMapping_Size(inst.as_ptr()), 10);
     }
 
-    let inst = Len::create_instance(py, (isize::MAX as usize) + 1).unwrap();
+    let inst = Len{l: (isize::MAX as usize) + 1}.into_object(py);
     py_expect_exception!(py, inst, "len(inst)", OverflowError);
 }
 
@@ -391,16 +393,16 @@ fn iterator() {
 struct StringMethods {}
 
 #[py::proto]
-impl PyObjectProtocol for StringMethods {
-    fn __str__(&self) -> PyResult<&'static str> {
+impl<'p> PyObjectProtocol<'p> for StringMethods {
+    fn __str__(&self, py: Python) -> PyResult<&'static str> {
         Ok("str")
     }
 
-    fn __repr__(&self) -> PyResult<&'static str> {
+    fn __repr__(&self, py: Python) -> PyResult<&'static str> {
         Ok("repr")
     }
 
-    fn __format__(&self, format_spec: String) -> PyResult<String> {
+    fn __format__(&self, py: Python, format_spec: String) -> PyResult<String> {
         Ok(format!("format({})", format_spec))
     }
 
@@ -408,7 +410,7 @@ impl PyObjectProtocol for StringMethods {
     //    Ok(PyString::new(py, "unicode"))
     //}
 
-    fn __bytes__(&self) -> PyResult<PyBytes> {
+    fn __bytes__(&self, py: Python) -> PyResult<Py<PyBytes>> {
         Ok(PyBytes::new(py, b"bytes"))
     }
 }
@@ -418,7 +420,7 @@ fn string_methods() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let obj = StringMethods::create_instance(py).unwrap();
+    let obj = StringMethods{}.into_object(py);
     py_assert!(py, obj, "str(obj) == 'str'");
     py_assert!(py, obj, "repr(obj) == 'repr'");
     py_assert!(py, obj, "'{0:x}'.format(obj) == 'format(x)'");
@@ -433,12 +435,12 @@ struct Comparisons {
 
 #[py::proto]
 impl PyObjectProtocol for Comparisons {
-    fn __hash__(&self) -> PyResult<usize> {
-        Ok(*self.val(py) as usize)
+    fn __hash__(&self, py: Python) -> PyResult<usize> {
+        Ok(self.val as usize)
     }
 
-    fn __bool__(&self) -> PyResult<bool> {
-        Ok(*self.val(py) != 0)
+    fn __bool__(&self, py: Python) -> PyResult<bool> {
+        Ok(self.val != 0)
     }
 }
 
@@ -448,10 +450,10 @@ fn comparisons() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let zero = Comparisons::create_instance(py, 0).unwrap();
-    let one = Comparisons::create_instance(py, 1).unwrap();
-    let ten = Comparisons::create_instance(py, 10).unwrap();
-    let minus_one = Comparisons::create_instance(py, -1).unwrap();
+    let zero = Comparisons{val: 0}.into_object(py);
+    let one = Comparisons{val: 1}.into_object(py);
+    let ten = Comparisons{val: 10}.into_object(py);
+    let minus_one = Comparisons{val: -1}.into_object(py);
     py_assert!(py, one, "hash(one) == 1");
     py_assert!(py, ten, "hash(ten) == 10");
     py_assert!(py, minus_one, "hash(minus_one) == -2");
@@ -466,11 +468,11 @@ struct Sequence {}
 
 #[py::proto]
 impl PySequenceProtocol for Sequence {
-    fn __len__(&self) -> PyResult<usize> {
+    fn __len__(&self, py: Python) -> PyResult<usize> {
         Ok(5)
     }
 
-    fn __getitem__(&self, key: isize) -> PyResult<isize> {
+    fn __getitem__(&self, py: Python, key: isize) -> PyResult<isize> {
         if key == 5 {
             return Err(PyErr::new::<exc::IndexError, NoArgs>(py, NoArgs));
         }
@@ -483,7 +485,7 @@ fn sequence() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let c = Sequence::create_instance(py).unwrap();
+    let c = Sequence{}.into_object(py);
     py_assert!(py, c, "list(c) == [0, 1, 2, 3, 4]");
     py_expect_exception!(py, c, "c['abc']", TypeError);
 }
@@ -496,7 +498,7 @@ struct Callable {}
 impl Callable {
 
     #[__call__]
-    fn __call__(&self, arg: i32) -> PyResult<i32> {
+    fn __call__(&self, py: Python, arg: i32) -> PyResult<i32> {
         Ok(arg * 6)
     }
 }
@@ -506,11 +508,11 @@ fn callable() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let c = Callable::create_instance(py).unwrap();
+    let c = Callable{}.into_object(py);
     py_assert!(py, c, "callable(c)");
     py_assert!(py, c, "c(7) == 42");
 
-    let nc = Comparisons::create_instance(py, 0).unwrap();
+    let nc = Comparisons{val: 0}.into_object(py);
     py_assert!(py, nc, "not callable(nc)");
 }
 
@@ -522,9 +524,9 @@ struct SetItem {
 
 #[py::proto]
 impl PyMappingProtocol<'a> for SetItem {
-    fn __setitem__(&self, key: i32, val: i32) -> PyResult<()> {
-        *self.key_mut(py) = key;
-        *self.val_mut(py) = val;
+    fn __setitem__(&mut self, py: Python, key: i32, val: i32) -> PyResult<()> {
+        self.key = key;
+        self.val = val;
         Ok(())
     }
 }
@@ -534,7 +536,7 @@ fn setitem() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let c = SetItem::create_instance(0, 0).unwrap();
+    let c = py.init(SetItem{key: 0, val: 0});
     py_run!(py, c, "c[1] = 2");
     assert_eq!(c.key, 1);
     assert_eq!(c.val, 2);
@@ -548,8 +550,8 @@ struct DelItem {
 
 #[py::proto]
 impl PyMappingProtocol<'a> for DelItem {
-    fn __delitem__(&self, key: i32) -> PyResult<()> {
-        *self.key_mut(py) = key;
+    fn __delitem__(&mut self, py: Python, key: i32) -> PyResult<()> {
+        self.key = key;
         Ok(())
     }
 }
@@ -559,9 +561,9 @@ fn delitem() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let c = DelItem::create_instance(py, 0).unwrap();
+    let c = py.init(DelItem{key:0});
     py_run!(py, c, "del c[1]");
-    assert_eq!(*c.key(py), 1);
+    assert_eq!(c.key, 1);
     py_expect_exception!(py, c, "c[1] = 2", NotImplementedError);
 }
 
@@ -572,13 +574,13 @@ struct SetDelItem {
 
 #[py::proto]
 impl PyMappingProtocol for SetDelItem {
-    fn __setitem__(&self, key: i32, val: i32) -> PyResult<()> {
-        *self.val_mut(py) = Some(val);
+    fn __setitem__(&mut self, py: Python, key: i32, val: i32) -> PyResult<()> {
+        self.val = Some(val);
         Ok(())
     }
 
-    fn __delitem__(&self, key: i32) -> PyResult<()> {
-        *self.val_mut(py) = None;
+    fn __delitem__(&mut self, py: Python, key: i32) -> PyResult<()> {
+        self.val = None;
         Ok(())
     }
 }
@@ -588,11 +590,11 @@ fn setdelitem() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let c = SetDelItem::create_instance(py, None).unwrap();
+    let c = py.init(SetDelItem{val: None});
     py_run!(py, c, "c[1] = 2");
-    assert_eq!(*c.val(py), Some(2));
+    assert_eq!(c.val, Some(2));
     py_run!(py, c, "del c[1]");
-    assert_eq!(*c.val(py), None);
+    assert_eq!(c.val, None);
 }
 
 #[py::class]
@@ -600,7 +602,7 @@ struct Reversed {}
 
 #[py::proto]
 impl PyMappingProtocol for Reversed{
-    fn __reversed__(&self) -> PyResult<&'static str> {
+    fn __reversed__(&self, py: Python) -> PyResult<&'static str> {
         println!("__reversed__");
         Ok("I am reversed")
     }
@@ -611,7 +613,7 @@ fn reversed() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let c = Reversed::create_instance(py).unwrap();
+    let c = Reversed{}.into_object(py);
     py_run!(py, c, "assert reversed(c) == 'I am reversed'");
 }
 
@@ -620,7 +622,7 @@ struct Contains {}
 
 #[py::proto]
 impl PySequenceProtocol for Contains {
-    fn __contains__(&self, item: i32) -> PyResult<bool> {
+    fn __contains__(&self, py: Python, item: i32) -> PyResult<bool> {
         Ok(item >= 0)
     }
 }
@@ -630,7 +632,7 @@ fn contains() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let c = Contains::create_instance(py).unwrap();
+    let c = Contains{}.into_object(py);
     py_run!(py, c, "assert 1 in c");
     py_run!(py, c, "assert -1 not in c");
     py_expect_exception!(py, c, "assert 'wrong type' not in c", TypeError);
@@ -644,19 +646,19 @@ struct UnaryArithmetic {}
 #[py::proto]
 impl PyNumberProtocol for UnaryArithmetic {
 
-    fn __neg__(&self) -> PyResult<&'static str> {
+    fn __neg__(&self, py: Python) -> PyResult<&'static str> {
         Ok("neg")
     }
 
-    fn __pos__(&self) -> PyResult<&'static str> {
+    fn __pos__(&self, py: Python) -> PyResult<&'static str> {
         Ok("pos")
     }
 
-    fn __abs__(&self) -> PyResult<&'static str> {
+    fn __abs__(&self, py: Python) -> PyResult<&'static str> {
         Ok("abs")
     }
 
-    fn __invert__(&self) -> PyResult<&'static str> {
+    fn __invert__(&self, py: Python) -> PyResult<&'static str> {
         Ok("invert")
     }
 }
@@ -666,7 +668,7 @@ fn unary_arithmetic() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let c = UnaryArithmetic::create_instance(py).unwrap();
+    let c = UnaryArithmetic{}.into_object(py);
     py_run!(py, c, "assert -c == 'neg'");
     py_run!(py, c, "assert +c == 'pos'");
     py_run!(py, c, "assert abs(c) == 'abs'");
@@ -679,43 +681,43 @@ struct BinaryArithmetic {}
 
 #[py::proto]
 impl PyObjectProtocol for BinaryArithmetic {
-    fn __repr__(&self) -> PyResult<&'static str> {
+    fn __repr__(&self, py: Python) -> PyResult<&'static str> {
         Ok("BA")
     }
 }
 
 #[py::proto]
 impl PyNumberProtocol for BinaryArithmetic {
-    fn __add__(&self, rhs: PyObject) -> PyResult<String> {
-        Ok(format!("{:?} + {:?}", self.as_object(), rhs))
+    fn __add__(&self, py: Python, rhs: &PyObject) -> PyResult<String> {
+        Ok(format!("{:?} + {:?}", self, rhs))
     }
 
-    fn __sub__(&self, rhs: PyObject) -> PyResult<String> {
-        Ok(format!("{:?} - {:?}", self.as_object(), rhs))
+    fn __sub__(&self, py: Python, rhs: &PyObject) -> PyResult<String> {
+        Ok(format!("{:?} - {:?}", self, rhs))
     }
 
-    fn __mul__(&self, rhs: PyObject) -> PyResult<String> {
-        Ok(format!("{:?} * {:?}", self.as_object(), rhs))
+    fn __mul__(&self, py: Python, rhs: &PyObject) -> PyResult<String> {
+        Ok(format!("{:?} * {:?}", self, rhs))
     }
 
-    fn __lshift__(&self, rhs: PyObject) -> PyResult<String> {
-        Ok(format!("{:?} << {:?}", self.as_object(), rhs))
+    fn __lshift__(&self, py: Python, rhs: &PyObject) -> PyResult<String> {
+        Ok(format!("{:?} << {:?}", self, rhs))
     }
 
-    fn __rshift__(&self, rhs: PyObject) -> PyResult<String> {
-        Ok(format!("{:?} >> {:?}", self.as_object(), rhs))
+    fn __rshift__(&self, py: Python, rhs: &PyObject) -> PyResult<String> {
+        Ok(format!("{:?} >> {:?}", self, rhs))
     }
 
-    fn __and__(&self, rhs: PyObject) -> PyResult<String> {
-        Ok(format!("{:?} & {:?}", self.as_object(), rhs))
+    fn __and__(&self, py: Python, rhs: &PyObject) -> PyResult<String> {
+        Ok(format!("{:?} & {:?}", self, rhs))
     }
 
-    fn __xor__(&self, rhs: PyObject) -> PyResult<String> {
-        Ok(format!("{:?} ^ {:?}", self.as_object(), rhs))
+    fn __xor__(&self, py: Python, rhs: &PyObject) -> PyResult<String> {
+        Ok(format!("{:?} ^ {:?}", self, rhs))
     }
 
-    fn __or__(&self, rhs: PyObject) -> PyResult<String> {
-        Ok(format!("{:?} | {:?}", self.as_object(), rhs))
+    fn __or__(&self, py: Python, rhs: &PyObject) -> PyResult<String> {
+        Ok(format!("{:?} | {:?}", self, rhs))
     }
 }
 
@@ -724,7 +726,7 @@ fn binary_arithmetic() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let c = BinaryArithmetic::create_instance(py).unwrap();
+    let c = BinaryArithmetic{}.into_object(py);
     py_run!(py, c, "assert c + c == 'BA + BA'");
     py_run!(py, c, "assert c + 1 == 'BA + 1'");
     py_run!(py, c, "assert 1 + c == '1 + BA'");
@@ -751,35 +753,38 @@ struct RichComparisons {}
 
 #[py::proto]
 impl PyObjectProtocol for RichComparisons {
-    fn __repr__(&self) -> PyResult<&'static str> {
+    fn __repr__(&self, py: Python) -> PyResult<&'static str> {
         Ok("RC")
     }
 
-    fn __richcmp__(&self, other: PyObject, op: CompareOp) -> PyResult<String> {
+    fn __richcmp__(&self, py: Python, other: &PyObject, op: CompareOp) -> PyResult<String> {
         match op {
-            CompareOp::Lt => Ok(format!("{:?} < {:?}", self.as_object(), other)),
-            CompareOp::Le => Ok(format!("{:?} <= {:?}", self.as_object(), other)),
-            CompareOp::Eq => Ok(format!("{:?} == {:?}", self.as_object(), other)),
-            CompareOp::Ne => Ok(format!("{:?} != {:?}", self.as_object(), other)),
-            CompareOp::Gt => Ok(format!("{:?} > {:?}", self.as_object(), other)),
-            CompareOp::Ge => Ok(format!("{:?} >= {:?}", self.as_object(), other))
+            CompareOp::Lt => Ok(format!("{:?} < {:?}", self.__repr__(py), other)),
+            CompareOp::Le => Ok(format!("{:?} <= {:?}", self.__repr__(py), other)),
+            CompareOp::Eq => Ok(format!("{:?} == {:?}", self.__repr__(py), other)),
+            CompareOp::Ne => Ok(format!("{:?} != {:?}", self.__repr__(py), other)),
+            CompareOp::Gt => Ok(format!("{:?} > {:?}", self.__repr__(py), other)),
+            CompareOp::Ge => Ok(format!("{:?} >= {:?}", self.__repr__(py), other))
         }
     }
 }
 
 #[py::class]
-struct RichComparisons2 {}
+struct RichComparisons2 {
+    py: PythonToken<RichComparisons2>
+}
 
 #[py::proto]
 impl PyObjectProtocol for RichComparisons2 {
-    fn __repr__(&self) -> PyResult<&'static str> {
+    fn __repr__(&self, py: Python) -> PyResult<&'static str> {
         Ok("RC2")
     }
 
-    fn __richcmp__(&self, other: PyObject, op: CompareOp) -> PyResult<PyObject> {
+    fn __richcmp__(&self, py: Python,
+                   other: &PyObject, op: CompareOp) -> PyResult<Py<PyObject>> {
         match op {
-            CompareOp::Eq => Ok(true.to_py_object(py).into_object()),
-            CompareOp::Ne => Ok(false.to_py_object(py).into_object()),
+            CompareOp::Eq => Ok(true.to_object(py).into_object()),
+            CompareOp::Ne => Ok(false.to_object(py).into_object()),
             _ => Ok(py.NotImplemented())
         }
     }
@@ -790,7 +795,7 @@ fn rich_comparisons() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let c = RichComparisons::create_instance(py).unwrap();
+    let c = RichComparisons{}.into_object(py);
     py_run!(py, c, "assert (c < c) == 'RC < RC'");
     py_run!(py, c, "assert (c < 1) == 'RC < 1'");
     py_run!(py, c, "assert (1 < c) == 'RC > 1'");
@@ -816,7 +821,7 @@ fn rich_comparisons_python_3_type_error() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let c2 = RichComparisons2::create_instance(py).unwrap();
+    let c2 = RichComparisons2{}.into_object(py);
     py_expect_exception!(py, c2, "c2 < c2", TypeError);
     py_expect_exception!(py, c2, "c2 < 1", TypeError);
     py_expect_exception!(py, c2, "1 < c2", TypeError);
@@ -844,51 +849,51 @@ struct InPlaceOperations {
 
 #[py::proto]
 impl PyObjectProtocol for InPlaceOperations {
-    fn __repr__(&self) -> PyResult<String> {
-        Ok(format!("IPO({:?})", self.value(py)))
+    fn __repr__(&self, py: Python) -> PyResult<String> {
+        Ok(format!("IPO({:?})", self.value))
     }
 }
 
 #[py::proto]
 impl PyNumberProtocol for InPlaceOperations {
-    fn __iadd__(&self, other: u32) -> PyResult<Self> {
-        *self.value_mut(py) = *self.value(py) + other;
-        Ok(self.clone_ref(py))
+    fn __iadd__(&mut self, py: Python, other: u32) -> PyResult<()> {
+        self.value = self.value + other;
+        Ok(())
     }
 
-    fn __isub__(&self, other: u32) -> PyResult<Self> {
-        *self.value_mut(py) = *self.value(py) - other;
-        Ok(self.clone_ref(py))
+    fn __isub__(&mut self, py: Python, other: u32) -> PyResult<()> {
+        self.value = self.value - other;
+        Ok(())
     }
 
-    fn __imul__(&self, other: u32) -> PyResult<Self> {
-        *self.value_mut(py) = *self.value(py) * other;
-        Ok(self.clone_ref(py))
+    fn __imul__(&mut self, py: Python, other: u32) -> PyResult<()> {
+        self.value = self.value * other;
+        Ok(())
     }
 
-    fn __ilshift__(&self, other: u32) -> PyResult<Self> {
-        *self.value_mut(py) = *self.value(py) << other;
-        Ok(self.clone_ref(py))
+    fn __ilshift__(&mut self, py: Python, other: u32) -> PyResult<()> {
+        self.value = self.value << other;
+        Ok(())
     }
 
-    fn __irshift__(&self, other: u32) -> PyResult<Self> {
-        *self.value_mut(py) = *self.value(py) >> other;
-        Ok(self.clone_ref(py))
+    fn __irshift__(&mut self, py: Python, other: u32) -> PyResult<()> {
+        self.value = self.value >> other;
+        Ok(())
     }
 
-    fn __iand__(&self, other: u32) -> PyResult<Self> {
-        *self.value_mut(py) = *self.value(py) & other;
-        Ok(self.clone_ref(py))
+    fn __iand__(&mut self, py: Python, other: u32) -> PyResult<()> {
+        self.value = self.value & other;
+        Ok(())
     }
 
-    fn __ixor__(&self, other: u32) -> PyResult<Self> {
-        *self.value_mut(py) = *self.value(py) ^ other;
-        Ok(self.clone_ref(py))
+    fn __ixor__(&mut self, py: Python, other: u32) -> PyResult<()> {
+        self.value = self.value ^ other;
+        Ok(())
     }
 
-    fn __ior__(&self, other: u32) -> PyResult<Self> {
-        *self.value_mut(py) = *self.value(py) | other;
-        Ok(self.clone_ref(py))
+    fn __ior__(&mut self, py: Python, other: u32) -> PyResult<()> {
+        self.value = self.value | other;
+        Ok(())
     }
 }
 
@@ -897,28 +902,28 @@ fn inplace_operations() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let c = InPlaceOperations::create_instance(py, 0).unwrap();
+    let c = InPlaceOperations{value: 0}.into_object(py);
     py_run!(py, c, "d = c; c += 1; assert repr(c) == repr(d) == 'IPO(1)'");
 
-    let c = InPlaceOperations::create_instance(py, 10).unwrap();
+    let c = InPlaceOperations{value:10}.into_object(py);
     py_run!(py, c, "d = c; c -= 1; assert repr(c) == repr(d) == 'IPO(9)'");
 
-    let c = InPlaceOperations::create_instance(py, 3).unwrap();
+    let c = InPlaceOperations{value: 3}.into_object(py);
     py_run!(py, c, "d = c; c *= 3; assert repr(c) == repr(d) == 'IPO(9)'");
 
-    let c = InPlaceOperations::create_instance(py, 3).unwrap();
+    let c = InPlaceOperations{value: 3}.into_object(py);
     py_run!(py, c, "d = c; c <<= 2; assert repr(c) == repr(d) == 'IPO(12)'");
 
-    let c = InPlaceOperations::create_instance(py, 12).unwrap();
+    let c = InPlaceOperations{value: 12}.into_object(py);
     py_run!(py, c, "d = c; c >>= 2; assert repr(c) == repr(d) == 'IPO(3)'");
 
-    let c = InPlaceOperations::create_instance(py, 12).unwrap();
+    let c = InPlaceOperations{value: 12}.into_object(py);
     py_run!(py, c, "d = c; c &= 10; assert repr(c) == repr(d) == 'IPO(8)'");
 
-    let c = InPlaceOperations::create_instance(py, 12).unwrap();
+    let c = InPlaceOperations{value: 12}.into_object(py);
     py_run!(py, c, "d = c; c |= 3; assert repr(c) == repr(d) == 'IPO(15)'");
 
-    let c = InPlaceOperations::create_instance(py, 12).unwrap();
+    let c = InPlaceOperations{value: 12}.into_object(py);
     py_run!(py, c, "d = c; c ^= 5; assert repr(c) == repr(d) == 'IPO(9)'");
 }
 
@@ -930,11 +935,11 @@ struct ContextManager {
 #[py::proto]
 impl<'p> PyContextProtocol<'p> for ContextManager {
 
-    fn __enter__(&self) -> PyResult<i32> {
+    fn __enter__(&mut self, py: Python) -> PyResult<i32> {
         Ok(42)
     }
 
-    fn __exit__(&mut self,
+    fn __exit__(&mut self, py: Python,
                 ty: Option<&'p PyType>,
                 value: Option<&'p PyObject>,
                 traceback: Option<&'p PyObject>) -> PyResult<bool> {
@@ -952,17 +957,19 @@ fn context_manager() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let c = ContextManager::create_instance(py, false).unwrap();
+    let c = py.init(ContextManager{exit_called: false});
     py_run!(py, c, "with c as x:\n  assert x == 42");
-    assert!(*c.exit_called(py));
+    assert!(c.exit_called);
 
-    *c.exit_called_mut(py) = false;
+    c.exit_called = false;
     py_run!(py, c, "with c as x:\n  raise ValueError");
-    assert!(*c.exit_called(py));
+    assert!(c.exit_called);
 
-    *c.exit_called_mut(py) = false;
-    py_expect_exception!(py, c, "with c as x:\n  raise NotImplementedError", NotImplementedError);
-    assert!(*c.exit_called(py));
+    c.exit_called = false;
+    py_expect_exception!(
+        py, c, "with c as x:\n  raise NotImplementedError",
+        NotImplementedError);
+    assert!(c.exit_called);
 }
 
 
@@ -974,17 +981,17 @@ struct ClassWithProperties {
 #[py::methods]
 impl ClassWithProperties {
 
-    fn get_num(&self) -> PyResult<i32> {
-        Ok(*self.num(py))
+    fn get_num(&self, py: Python) -> PyResult<i32> {
+        Ok(self.num)
     }
 
     #[getter(DATA)]
-    fn get_data(&self) -> PyResult<i32> {
-        Ok(*self.num(py))
+    fn get_data(&self, py: Python) -> PyResult<i32> {
+        Ok(self.num)
     }
     #[setter(DATA)]
-    fn set(&self, value: i32) -> PyResult<()> {
-        *self.num_mut(py) = value;
+    fn set(&self, py: Python, value: i32) -> PyResult<()> {
+        self.num = value;
         Ok(())
     }
 }
@@ -995,7 +1002,7 @@ fn class_with_properties() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let inst = ClassWithProperties::create_instance(py, 10).unwrap();
+    let inst = ClassWithProperties{num: 10}.into_object(py);
 
     py_run!(py, inst, "assert inst.get_num() == 10");
     py_run!(py, inst, "assert inst.get_num() == inst.DATA");
@@ -1003,4 +1010,4 @@ fn class_with_properties() {
     py_run!(py, inst, "assert inst.get_num() == 20");
     py_run!(py, inst, "assert inst.get_num() == inst.DATA");
 
-}
\ No newline at end of file
+}