Remove PyToken completely; Fixes #94

examples/rustapi_module/src/datetime.rs

@@ -186,7 +186,7 @@ pub struct TzClass {}
 impl TzClass {
     #[new]
     fn __new__(obj: &PyRawObject) -> PyResult<()> {
-        obj.init(|_| TzClass {})
+        obj.init(|| TzClass {})
     }
 
     fn utcoffset(&self, py: Python, _dt: &PyDateTime) -> PyResult<Py<PyDelta>> {

examples/rustapi_module/src/othermod.rs

@@ -13,7 +13,7 @@ pub struct ModClass {
 impl ModClass {
     #[new]
     fn __new__(obj: &PyRawObject) -> PyResult<()> {
-        obj.init(|_| ModClass {
+        obj.init(|| ModClass {
             _somefield: String::from("contents"),
         })
     }

examples/rustapi_module/src/subclassing.rs

@@ -9,7 +9,7 @@ pub struct Subclassable {}
 impl Subclassable {
     #[new]
     fn __new__(obj: &PyRawObject) -> PyResult<()> {
-        obj.init(|_| Subclassable {})
+        obj.init(|| Subclassable {})
     }
 }
 

examples/word-count/src/lib.rs

@@ -21,7 +21,7 @@ struct WordCounter {
 impl WordCounter {
     #[new]
     fn __new__(obj: &PyRawObject, path: String) -> PyResult<()> {
-        obj.init(|_| WordCounter {
+        obj.init(|| WordCounter {
             path: PathBuf::from(path),
         })
     }

guide/src/class.md

@@ -59,7 +59,7 @@ impl MyClass {
 
      #[new]
      fn __new__(obj: &PyRawObject, num: i32) -> PyResult<()> {
-         obj.init(|_| {
+         obj.init(||   {
              MyClass {
                  num,
              }
@@ -101,7 +101,7 @@ struct BaseClass {
 impl BaseClass {
    #[new]
    fn __new__(obj: &PyRawObject) -> PyResult<()> {
-       obj.init(|_| BaseClass{ val1: 10 })
+       obj.init(||   BaseClass{ val1: 10 })
    }
 
    pub fn method(&self) -> PyResult<()> {
@@ -118,7 +118,7 @@ struct SubClass {
 impl SubClass {
    #[new]
    fn __new__(obj: &PyRawObject) -> PyResult<()> {
-       obj.init(|_| SubClass{ val2: 10 });
+       obj.init(||   SubClass{ val2: 10 });
        BaseClass::__new__(obj)
    }
 

guide/src/rust-cpython.md

@@ -41,7 +41,7 @@ struct MyClass {
 impl MyClass {
     #[new]
     fn __new__(obj: &PyRawObject, num: u32) -> PyResult<()> {
-        obj.init(|token| {
+        obj.init(|| {
             MyClass {
                 num,
             }

pyo3-derive-backend/src/py_class.rs

@@ -10,29 +10,20 @@ use utils;
 pub fn build_py_class(class: &mut syn::ItemStruct, attr: &Vec<syn::Expr>) -> TokenStream {
     let (params, flags, base) = parse_attribute(attr);
     let doc = utils::get_doc(&class.attrs, true);
-    let mut token: Option<syn::Ident> = None;
     let mut descriptors = Vec::new();
 
     if let syn::Fields::Named(ref mut fields) = class.fields {
         for field in fields.named.iter_mut() {
-            if is_python_token(field) {
+            let field_descs = parse_descriptors(field);
-                if token.is_none() {
+            if !field_descs.is_empty() {
-                    token = field.ident.clone();
+                descriptors.push((field.clone(), field_descs));
-                } else {
-                    panic!("You can only have one PyToken per class");
-                }
-            } else {
-                let field_descs = parse_descriptors(field);
-                if !field_descs.is_empty() {
-                    descriptors.push((field.clone(), field_descs));
-                }
             }
         }
     } else {
         panic!("#[pyclass] can only be used with C-style structs")
     }
 
-    impl_class(&class.ident, &base, token, doc, params, flags, descriptors)
+    impl_class(&class.ident, &base, doc, params, flags, descriptors)
 }
 
 fn parse_descriptors(item: &mut syn::Field) -> Vec<FnType> {
@@ -72,7 +63,6 @@ fn parse_descriptors(item: &mut syn::Field) -> Vec<FnType> {
 fn impl_class(
     cls: &syn::Ident,
     base: &syn::TypePath,
-    token: Option<syn::Ident>,
     doc: syn::Lit,
     params: HashMap<&'static str, syn::Expr>,
     flags: Vec<syn::Expr>,
@@ -83,38 +73,6 @@ fn impl_class(
         None => quote! { #cls }.to_string(),
     };
 
-    let extra = if let Some(token) = token {
-        Some(quote! {
-            impl ::pyo3::PyObjectWithToken for #cls {
-                fn py<'p>(&'p self) -> ::pyo3::Python<'p> {
-                    self.#token.py()
-                }
-            }
-            impl<'a> ::std::convert::From<&'a mut #cls> for &'a #cls
-            {
-                fn from(ob: &'a mut #cls) -> Self {
-                    unsafe{std::mem::transmute(ob)}
-                }
-            }
-            impl ::std::fmt::Debug for #cls {
-                fn fmt(&self, f : &mut ::std::fmt::Formatter) -> Result<(), ::std::fmt::Error> {
-                    use ::pyo3::ObjectProtocol;
-                    let s = self.repr().map_err(|_| ::std::fmt::Error)?;
-                    f.write_str(&s.to_string_lossy())
-                }
-            }
-            impl ::std::fmt::Display for #cls {
-                fn fmt(&self, f: &mut ::std::fmt::Formatter) -> Result<(), ::std::fmt::Error> {
-                    use ::pyo3::ObjectProtocol;
-                    let s = self.str().map_err(|_| ::std::fmt::Error)?;
-                    f.write_str(&s.to_string_lossy())
-                }
-            }
-        })
-    } else {
-        None
-    };
-
     let extra = {
         if let Some(freelist) = params.get("freelist") {
             Some(quote! {
@@ -133,11 +91,9 @@ fn impl_class(
                         }
                     }
                 }
-
-                #extra
             })
         } else {
-            extra
+            None
         }
     };
 
@@ -209,7 +165,7 @@ fn impl_class(
         // objects, so for now I'm keeping it
         impl ::pyo3::IntoPyObject for #cls {
             fn into_object(self, py: ::pyo3::Python) -> ::pyo3::PyObject {
-                ::pyo3::Py::new(py, |_| self).unwrap().into_object(py)
+                ::pyo3::Py::new(py, || self).unwrap().into_object(py)
             }
         }
 
@@ -337,18 +293,6 @@ fn impl_descriptors(cls: &syn::Type, descriptors: Vec<(syn::Field, Vec<FnType>)>
     }
 }
 
-fn is_python_token(field: &syn::Field) -> bool {
-    match field.ty {
-        syn::Type::Path(ref typath) => {
-            if let Some(segment) = typath.path.segments.last() {
-                return segment.value().ident.to_string() == "PyToken";
-            }
-        }
-        _ => (),
-    }
-    return false;
-}
-
 fn parse_attribute(
     args: &Vec<syn::Expr>,
 ) -> (

src/instance.rs

@@ -1,9 +1,7 @@
 // Copyright (c) 2017-present PyO3 Project and Contributors
 
 use std;
-use std::marker::PhantomData;
 use std::ptr::NonNull;
-use std::rc::Rc;
 
 use crate::conversion::{FromPyObject, IntoPyObject, ToPyObject};
 use crate::err::{PyErr, PyResult};
@@ -17,19 +15,6 @@ use crate::typeob::PyTypeCreate;
 use crate::typeob::{PyTypeInfo, PyTypeObject};
 use crate::types::PyObjectRef;
 
-pub struct PyToken(PhantomData<Rc<()>>);
-
-impl PyToken {
-    pub(crate) fn new() -> PyToken {
-        PyToken(PhantomData)
-    }
-
-    #[inline]
-    pub fn py(&self) -> Python {
-        unsafe { Python::assume_gil_acquired() }
-    }
-}
-
 /// Any instance that is managed Python can have access to `gil`.
 pub trait PyObjectWithToken: Sized {
     fn py(&self) -> Python;
@@ -174,7 +159,7 @@ where
     /// Returns `Py<T>`.
     pub fn new<F>(py: Python, f: F) -> PyResult<Py<T>>
     where
-        F: FnOnce(crate::PyToken) -> T,
+        F: FnOnce() -> T,
         T: PyTypeObject + PyTypeInfo,
     {
         let ob = <T as PyTypeCreate>::create(py)?;
@@ -188,7 +173,7 @@ where
     /// Returns references to `T`
     pub fn new_ref<F>(py: Python, f: F) -> PyResult<&T>
     where
-        F: FnOnce(crate::PyToken) -> T,
+        F: FnOnce() -> T,
         T: PyTypeObject + PyTypeInfo,
     {
         let ob = <T as PyTypeCreate>::create(py)?;
@@ -201,7 +186,7 @@ where
     /// Returns mutable references to `T`
     pub fn new_mut<F>(py: Python, f: F) -> PyResult<&mut T>
     where
-        F: FnOnce(crate::PyToken) -> T,
+        F: FnOnce() -> T,
         T: PyTypeObject + PyTypeInfo,
     {
         let ob = <T as PyTypeCreate>::create(py)?;

src/lib.rs

@@ -143,7 +143,7 @@ pub use crate::conversion::{
     ToBorrowedObject, ToPyObject,
 };
 pub use crate::err::{PyDowncastError, PyErr, PyErrArguments, PyErrValue, PyResult};
-pub use crate::instance::{AsPyRef, Py, PyNativeType, PyObjectWithToken, PyToken};
+pub use crate::instance::{AsPyRef, Py, PyNativeType, PyObjectWithToken};
 pub use crate::noargs::NoArgs;
 pub use crate::object::PyObject;
 pub use crate::objectprotocol::ObjectProtocol;

src/prelude.rs

@@ -12,7 +12,7 @@
 
 pub use crate::conversion::{FromPyObject, IntoPyObject, PyTryFrom, PyTryInto, ToPyObject};
 pub use crate::err::{PyErr, PyResult};
-pub use crate::instance::{AsPyRef, Py, PyToken};
+pub use crate::instance::{AsPyRef, Py};
 pub use crate::noargs::NoArgs;
 pub use crate::object::PyObject;
 pub use crate::objectprotocol::ObjectProtocol;

src/python.rs

@@ -5,7 +5,7 @@
 use crate::conversion::PyTryFrom;
 use crate::err::{PyDowncastError, PyErr, PyResult};
 use crate::ffi;
-use crate::instance::{AsPyRef, Py, PyToken};
+use crate::instance::{AsPyRef, Py};
 use crate::object::PyObject;
 use crate::pythonrun::{self, GILGuard};
 use crate::typeob::PyTypeCreate;
@@ -256,7 +256,7 @@ impl<'p> Python<'p> {
     #[inline]
     pub fn init<T, F>(self, f: F) -> PyResult<Py<T>>
     where
-        F: FnOnce(PyToken) -> T,
+        F: FnOnce() -> T,
         T: PyTypeCreate,
     {
         Py::new(self, f)
@@ -267,7 +267,7 @@ impl<'p> Python<'p> {
     #[inline]
     pub fn init_ref<T, F>(self, f: F) -> PyResult<&'p T>
     where
-        F: FnOnce(PyToken) -> T,
+        F: FnOnce() -> T,
         T: PyTypeCreate,
     {
         Py::new_ref(self, f)
@@ -278,7 +278,7 @@ impl<'p> Python<'p> {
     #[inline]
     pub fn init_mut<T, F>(self, f: F) -> PyResult<&'p mut T>
     where
-        F: FnOnce(PyToken) -> T,
+        F: FnOnce() -> T,
         T: PyTypeCreate,
     {
         Py::new_mut(self, f)

src/typeob.rs

@@ -8,14 +8,14 @@ use std::ffi::CString;
 use std::mem;
 use std::os::raw::c_void;
 
-use crate::{class, ffi, pythonrun};
 use crate::class::methods::PyMethodDefType;
 use crate::err::{PyErr, PyResult};
-use crate::instance::{Py, PyObjectWithToken, PyToken};
+use crate::instance::{Py, PyObjectWithToken};
-use crate::python::{IntoPyPointer, Python};
 use crate::python::ToPyPointer;
+use crate::python::{IntoPyPointer, Python};
 use crate::types::PyObjectRef;
 use crate::types::PyType;
+use crate::{class, ffi, pythonrun};
 
 /// Python type information.
 pub trait PyTypeInfo {
@@ -85,7 +85,7 @@ pub const PY_TYPE_FLAG_DICT: usize = 1 << 3;
 /// impl MyClass {
 ///    #[new]
 ///    fn __new__(obj: &PyRawObject) -> PyResult<()> {
-///        obj.init(|_| MyClass { })
+///        obj.init(||   MyClass { })
 ///    }
 /// }
 /// ```
@@ -142,11 +142,11 @@ impl PyRawObject {
     }
 
     pub fn init<T, F>(&self, f: F) -> PyResult<()>
-        where
+    where
-            F: FnOnce(PyToken) -> T,
+        F: FnOnce() -> T,
-            T: PyTypeInfo,
+        T: PyTypeInfo,
     {
-        let value = f(PyToken::new());
+        let value = f();
 
         unsafe {
             let ptr = (self.ptr as *mut u8).offset(T::OFFSET) as *mut T;
@@ -208,7 +208,9 @@ pub trait PyObjectAlloc: PyTypeInfo {
     unsafe fn drop(_py: Python, _obj: *mut ffi::PyObject) {}
 }
 
-impl<T> PyObjectAlloc for T where T: PyTypeInfo
+impl<T> PyObjectAlloc for T
+where
+    T: PyTypeInfo,
 {
     #[allow(unconditional_recursion)]
     /// Calls the rust destructor for the object.
@@ -231,11 +233,11 @@ impl<T> PyObjectAlloc for T where T: PyTypeInfo
         Self::drop(py, obj);
 
         #[cfg(Py_3)]
-            {
+        {
-                if ffi::PyObject_CallFinalizerFromDealloc(obj) < 0 {
+            if ffi::PyObject_CallFinalizerFromDealloc(obj) < 0 {
-                    return;
+                return;
-                }
             }
+        }
 
         match Self::type_object().tp_free {
             Some(free) => free(obj as *mut c_void),
@@ -310,8 +312,8 @@ pub trait PyTypeCreate: PyObjectAlloc + PyTypeInfo + Sized {
 impl<T> PyTypeCreate for T where T: PyObjectAlloc + PyTypeInfo + Sized {}
 
 impl<T> PyTypeObject for T
-    where
+where
-        T: PyTypeCreate,
+    T: PyTypeCreate,
 {
     fn init_type() {
         <T as PyTypeCreate>::init_type()
@@ -325,8 +327,8 @@ impl<T> PyTypeObject for T
 /// Register new type in python object system.
 #[cfg(not(Py_LIMITED_API))]
 pub fn initialize_type<T>(py: Python, module_name: Option<&str>) -> PyResult<()>
-    where
+where
-        T: PyObjectAlloc + PyTypeInfo,
+    T: PyObjectAlloc + PyTypeInfo,
 {
     // type name
     let name = match module_name {
@@ -463,8 +465,8 @@ fn async_methods<T>(type_info: &mut ffi::PyTypeObject) {
 fn async_methods<T>(_type_info: &mut ffi::PyTypeObject) {}
 
 unsafe extern "C" fn tp_dealloc_callback<T>(obj: *mut ffi::PyObject)
-    where
+where
-        T: PyObjectAlloc,
+    T: PyObjectAlloc,
 {
     let _pool = pythonrun::GILPool::new_no_pointers();
     let py = Python::assume_gil_acquired();
@@ -476,9 +478,9 @@ fn py_class_flags<T: PyTypeInfo>(type_object: &mut ffi::PyTypeObject) {
     if type_object.tp_traverse != None
         || type_object.tp_clear != None
         || T::FLAGS & PY_TYPE_FLAG_GC != 0
-        {
+    {
-            type_object.tp_flags = ffi::Py_TPFLAGS_DEFAULT | ffi::Py_TPFLAGS_HAVE_GC;
+        type_object.tp_flags = ffi::Py_TPFLAGS_DEFAULT | ffi::Py_TPFLAGS_HAVE_GC;
-        } else {
+    } else {
         type_object.tp_flags = ffi::Py_TPFLAGS_DEFAULT;
     }
     if T::FLAGS & PY_TYPE_FLAG_BASETYPE != 0 {
@@ -491,10 +493,10 @@ fn py_class_flags<T: PyTypeInfo>(type_object: &mut ffi::PyTypeObject) {
     if type_object.tp_traverse != None
         || type_object.tp_clear != None
         || T::FLAGS & PY_TYPE_FLAG_GC != 0
-        {
+    {
-            type_object.tp_flags =
+        type_object.tp_flags =
-                ffi::Py_TPFLAGS_DEFAULT | ffi::Py_TPFLAGS_CHECKTYPES | ffi::Py_TPFLAGS_HAVE_GC;
+            ffi::Py_TPFLAGS_DEFAULT | ffi::Py_TPFLAGS_CHECKTYPES | ffi::Py_TPFLAGS_HAVE_GC;
-        } else {
+    } else {
         type_object.tp_flags = ffi::Py_TPFLAGS_DEFAULT | ffi::Py_TPFLAGS_CHECKTYPES;
     }
     if !type_object.tp_as_buffer.is_null() {
@@ -583,27 +585,27 @@ fn py_class_properties<T>() -> Vec<ffi::PyGetSetDef> {
     for def in <T as class::methods::PyMethodsProtocolImpl>::py_methods()
         .iter()
         .chain(<T as class::methods::PyPropMethodsProtocolImpl>::py_methods().iter())
-        {
+    {
-            match *def {
+        match *def {
-                PyMethodDefType::Getter(ref getter) => {
+            PyMethodDefType::Getter(ref getter) => {
-                    let name = getter.name.to_string();
+                let name = getter.name.to_string();
-                    if !defs.contains_key(&name) {
+                if !defs.contains_key(&name) {
-                        let _ = defs.insert(name.clone(), ffi::PyGetSetDef_INIT);
+                    let _ = defs.insert(name.clone(), ffi::PyGetSetDef_INIT);
-                    }
-                    let def = defs.get_mut(&name).expect("Failed to call get_mut");
-                    getter.copy_to(def);
                 }
-                PyMethodDefType::Setter(ref setter) => {
+                let def = defs.get_mut(&name).expect("Failed to call get_mut");
-                    let name = setter.name.to_string();
+                getter.copy_to(def);
-                    if !defs.contains_key(&name) {
-                        let _ = defs.insert(name.clone(), ffi::PyGetSetDef_INIT);
-                    }
-                    let def = defs.get_mut(&name).expect("Failed to call get_mut");
-                    setter.copy_to(def);
-                }
-                _ => (),
             }
+            PyMethodDefType::Setter(ref setter) => {
+                let name = setter.name.to_string();
+                if !defs.contains_key(&name) {
+                    let _ = defs.insert(name.clone(), ffi::PyGetSetDef_INIT);
+                }
+                let def = defs.get_mut(&name).expect("Failed to call get_mut");
+                setter.copy_to(def);
+            }
+            _ => (),
         }
+    }
 
     defs.values().cloned().collect()
 }

tests/test_arithmetics.rs

@@ -36,7 +36,7 @@ fn unary_arithmetic() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let c = py.init(|_| UnaryArithmetic {}).unwrap();
+    let c = py.init(|| UnaryArithmetic {}).unwrap();
     py_run!(py, c, "assert -c == 'neg'");
     py_run!(py, c, "assert +c == 'pos'");
     py_run!(py, c, "assert abs(c) == 'abs'");
@@ -114,7 +114,7 @@ fn inplace_operations() {
     let py = gil.python();
 
     let init = |value, code| {
-        let c = py.init(|_| InPlaceOperations { value }).unwrap();
+        let c = py.init(|| InPlaceOperations { value }).unwrap();
         py_run!(py, c, code);
     };
 
@@ -168,7 +168,7 @@ fn binary_arithmetic() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let c = py.init(|_| BinaryArithmetic {}).unwrap();
+    let c = py.init(|| BinaryArithmetic {}).unwrap();
     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'");
@@ -234,7 +234,7 @@ fn rich_comparisons() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let c = py.init(|_| RichComparisons {}).unwrap();
+    let c = py.init(|| RichComparisons {}).unwrap();
     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'");
@@ -261,7 +261,7 @@ fn rich_comparisons_python_3_type_error() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let c2 = py.init(|_| RichComparisons2 {}).unwrap();
+    let c2 = py.init(|| RichComparisons2 {}).unwrap();
     py_expect_exception!(py, c2, "c2 < c2", TypeError);
     py_expect_exception!(py, c2, "c2 < 1", TypeError);
     py_expect_exception!(py, c2, "1 < c2", TypeError);

tests/test_buffer_protocol.rs

@@ -71,7 +71,7 @@ fn test_buffer() {
     let py = gil.python();
 
     let t = py
-        .init(|_| TestClass {
+        .init(|| TestClass {
             vec: vec![b' ', b'2', b'3'],
         })
         .unwrap();
@@ -88,7 +88,7 @@ fn test_buffer() {
     let py = gil.python();
 
     let t = py
-        .init(|_| TestClass {
+        .init(|| TestClass {
             vec: vec![b' ', b'2', b'3'],
         })
         .unwrap();

tests/test_class_new.rs

@@ -12,7 +12,7 @@ struct EmptyClassWithNew {}
 impl EmptyClassWithNew {
     #[__new__]
     fn __new__(obj: &PyRawObject) -> PyResult<()> {
-        obj.init(|_| EmptyClassWithNew {})
+        obj.init(|| EmptyClassWithNew {})
     }
 }
 
@@ -37,7 +37,7 @@ struct NewWithOneArg {
 impl NewWithOneArg {
     #[new]
     fn __new__(obj: &PyRawObject, arg: i32) -> PyResult<()> {
-        obj.init(|_| NewWithOneArg { _data: arg })
+        obj.init(|| NewWithOneArg { _data: arg })
     }
 }
 
@@ -61,7 +61,7 @@ struct NewWithTwoArgs {
 impl NewWithTwoArgs {
     #[new]
     fn __new__(obj: &PyRawObject, arg1: i32, arg2: i32) -> PyResult<()> {
-        obj.init(|_| NewWithTwoArgs {
+        obj.init(|| NewWithTwoArgs {
             _data1: arg1,
             _data2: arg2,
         })

tests/test_dunder.rs

@@ -33,14 +33,14 @@ fn len() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let inst = Py::new(py, |_| Len { l: 10 }).unwrap();
+    let inst = Py::new(py, || Len { l: 10 }).unwrap();
     py_assert!(py, inst, "len(inst) == 10");
     unsafe {
         assert_eq!(ffi::PyObject_Size(inst.as_ptr()), 10);
         assert_eq!(ffi::PyMapping_Size(inst.as_ptr()), 10);
     }
 
-    let inst = Py::new(py, |_| Len {
+    let inst = Py::new(py, || Len {
         l: (isize::MAX as usize) + 1,
     })
     .unwrap();
@@ -68,7 +68,7 @@ fn iterator() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let inst = Py::new(py, |_| Iterator {
+    let inst = Py::new(py, || Iterator {
         iter: Box::new(5..8),
     })
     .unwrap();
@@ -110,7 +110,7 @@ fn string_methods() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let obj = Py::new(py, |_| StringMethods {}).unwrap();
+    let obj = Py::new(py, || StringMethods {}).unwrap();
     py_assert!(py, obj, "str(obj) == 'str'");
     py_assert!(py, obj, "repr(obj) == 'repr'");
     py_assert!(py, obj, "'{0:x}'.format(obj) == 'format(x)'");
@@ -123,7 +123,7 @@ fn string_methods() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let obj = Py::new(py, |_| StringMethods {}).unwrap();
+    let obj = Py::new(py, || StringMethods {}).unwrap();
     py_assert!(py, obj, "str(obj) == 'str'");
     py_assert!(py, obj, "repr(obj) == 'repr'");
     py_assert!(py, obj, "unicode(obj) == 'unicode'");
@@ -150,10 +150,10 @@ fn comparisons() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let zero = Py::new(py, |_| Comparisons { val: 0 }).unwrap();
+    let zero = Py::new(py, || Comparisons { val: 0 }).unwrap();
-    let one = Py::new(py, |_| Comparisons { val: 1 }).unwrap();
+    let one = Py::new(py, || Comparisons { val: 1 }).unwrap();
-    let ten = Py::new(py, |_| Comparisons { val: 10 }).unwrap();
+    let ten = Py::new(py, || Comparisons { val: 10 }).unwrap();
-    let minus_one = Py::new(py, |_| Comparisons { val: -1 }).unwrap();
+    let minus_one = Py::new(py, || Comparisons { val: -1 }).unwrap();
     py_assert!(py, one, "hash(one) == 1");
     py_assert!(py, ten, "hash(ten) == 10");
     py_assert!(py, minus_one, "hash(minus_one) == -2");
@@ -184,7 +184,7 @@ fn sequence() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let c = py.init(|_| Sequence {}).unwrap();
+    let c = py.init(|| Sequence {}).unwrap();
     py_assert!(py, c, "list(c) == [0, 1, 2, 3, 4]");
     py_expect_exception!(py, c, "c['abc']", TypeError);
 }
@@ -205,11 +205,11 @@ fn callable() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let c = py.init(|_| Callable {}).unwrap();
+    let c = py.init(|| Callable {}).unwrap();
     py_assert!(py, c, "callable(c)");
     py_assert!(py, c, "c(7) == 42");
 
-    let nc = py.init(|_| Comparisons { val: 0 }).unwrap();
+    let nc = py.init(|| Comparisons { val: 0 }).unwrap();
     py_assert!(py, nc, "not callable(nc)");
 }
 
@@ -233,7 +233,7 @@ fn setitem() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let c = py.init_ref(|_| SetItem { key: 0, val: 0 }).unwrap();
+    let c = py.init_ref(|| SetItem { key: 0, val: 0 }).unwrap();
     py_run!(py, c, "c[1] = 2");
     assert_eq!(c.key, 1);
     assert_eq!(c.val, 2);
@@ -258,7 +258,7 @@ fn delitem() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let c = py.init_ref(|_| DelItem { key: 0 }).unwrap();
+    let c = py.init_ref(|| DelItem { key: 0 }).unwrap();
     py_run!(py, c, "del c[1]");
     assert_eq!(c.key, 1);
     py_expect_exception!(py, c, "c[1] = 2", NotImplementedError);
@@ -287,7 +287,7 @@ fn setdelitem() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let c = py.init_ref(|_| SetDelItem { val: None }).unwrap();
+    let c = py.init_ref(|| SetDelItem { val: None }).unwrap();
     py_run!(py, c, "c[1] = 2");
     assert_eq!(c.val, Some(2));
     py_run!(py, c, "del c[1]");
@@ -309,7 +309,7 @@ fn reversed() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let c = py.init(|_| Reversed {}).unwrap();
+    let c = py.init(|| Reversed {}).unwrap();
     py_run!(py, c, "assert reversed(c) == 'I am reversed'");
 }
 
@@ -328,7 +328,7 @@ fn contains() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let c = py.init(|_| Contains {}).unwrap();
+    let c = py.init(|| Contains {}).unwrap();
     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);
@@ -367,7 +367,7 @@ fn context_manager() {
     let py = gil.python();
 
     let c = py
-        .init_mut(|_| ContextManager { exit_called: false })
+        .init_mut(|| ContextManager { exit_called: false })
         .unwrap();
     py_run!(py, c, "with c as x: assert x == 42");
     assert!(c.exit_called);
@@ -425,7 +425,7 @@ fn test_cls_impl() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let ob = py.init(|_| Test {}).unwrap();
+    let ob = py.init(|| Test {}).unwrap();
     let d = PyDict::new(py);
     d.set_item("ob", ob).unwrap();
 
@@ -441,7 +441,7 @@ struct DunderDictSupport {}
 fn dunder_dict_support() {
     let gil = Python::acquire_gil();
     let py = gil.python();
-    let inst = Py::new_ref(py, |_| DunderDictSupport {}).unwrap();
+    let inst = Py::new_ref(py, || DunderDictSupport {}).unwrap();
     py_run!(
         py,
         inst,
@@ -459,7 +459,7 @@ struct WeakRefDunderDictSupport {}
 fn weakref_dunder_dict_support() {
     let gil = Python::acquire_gil();
     let py = gil.python();
-    let inst = Py::new_ref(py, |_| WeakRefDunderDictSupport {}).unwrap();
+    let inst = Py::new_ref(py, || WeakRefDunderDictSupport {}).unwrap();
     py_run!(
         py,
         inst,

tests/test_gc.rs

@@ -29,8 +29,8 @@ fn class_with_freelist() {
         let gil = Python::acquire_gil();
         let py = gil.python();
 
-        let inst = Py::new(py, |_| ClassWithFreelist {}).unwrap();
+        let inst = Py::new(py, || ClassWithFreelist {}).unwrap();
-        let _inst2 = Py::new(py, |_| ClassWithFreelist {}).unwrap();
+        let _inst2 = Py::new(py, || ClassWithFreelist {}).unwrap();
         ptr = inst.as_ptr();
         drop(inst);
     }
@@ -39,10 +39,10 @@ fn class_with_freelist() {
         let gil = Python::acquire_gil();
         let py = gil.python();
 
-        let inst3 = Py::new(py, |_| ClassWithFreelist {}).unwrap();
+        let inst3 = Py::new(py, || ClassWithFreelist {}).unwrap();
         assert_eq!(ptr, inst3.as_ptr());
 
-        let inst4 = Py::new(py, |_| ClassWithFreelist {}).unwrap();
+        let inst4 = Py::new(py, || ClassWithFreelist {}).unwrap();
         assert_ne!(ptr, inst4.as_ptr())
     }
 }
@@ -73,7 +73,7 @@ fn data_is_dropped() {
         let gil = Python::acquire_gil();
         let py = gil.python();
         let inst = py
-            .init(|_| DataIsDropped {
+            .init(|| DataIsDropped {
                 member1: TestDropCall {
                     drop_called: Arc::clone(&drop_called1),
                 },
@@ -119,7 +119,7 @@ fn create_pointers_in_drop() {
         let empty = PyTuple::empty(py);
         ptr = empty.as_ptr();
         cnt = empty.get_refcnt() - 1;
-        let inst = py.init(|_| ClassWithDrop {}).unwrap();
+        let inst = py.init(|| ClassWithDrop {}).unwrap();
         drop(inst);
     }
 
@@ -162,7 +162,7 @@ fn gc_integration() {
     {
         let gil = Python::acquire_gil();
         let py = gil.python();
-        let inst = Py::new_ref(py, |_| GCIntegration {
+        let inst = Py::new_ref(py, || GCIntegration {
             self_ref: RefCell::new(py.None()),
             dropped: TestDropCall {
                 drop_called: Arc::clone(&drop_called),
@@ -186,7 +186,7 @@ struct GCIntegration2 {}
 fn gc_integration2() {
     let gil = Python::acquire_gil();
     let py = gil.python();
-    let inst = Py::new_ref(py, |_| GCIntegration2 {}).unwrap();
+    let inst = Py::new_ref(py, || GCIntegration2 {}).unwrap();
     py_run!(py, inst, "import gc; assert inst in gc.get_objects()");
 }
 
@@ -197,7 +197,7 @@ struct WeakRefSupport {}
 fn weakref_support() {
     let gil = Python::acquire_gil();
     let py = gil.python();
-    let inst = Py::new_ref(py, |_| WeakRefSupport {}).unwrap();
+    let inst = Py::new_ref(py, || WeakRefSupport {}).unwrap();
     py_run!(
         py,
         inst,
@@ -214,7 +214,7 @@ struct BaseClassWithDrop {
 impl BaseClassWithDrop {
     #[new]
     fn __new__(obj: &PyRawObject) -> PyResult<()> {
-        obj.init(|_| BaseClassWithDrop { data: None })
+        obj.init(|| BaseClassWithDrop { data: None })
     }
 }
 
@@ -235,7 +235,7 @@ struct SubClassWithDrop {
 impl SubClassWithDrop {
     #[new]
     fn __new__(obj: &PyRawObject) -> PyResult<()> {
-        obj.init(|_| SubClassWithDrop { data: None })?;
+        obj.init(|| SubClassWithDrop { data: None })?;
         BaseClassWithDrop::__new__(obj)
     }
 }

tests/test_getter_setter.rs

@@ -35,7 +35,7 @@ fn class_with_properties() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let inst = py.init(|_| ClassWithProperties { num: 10 }).unwrap();
+    let inst = py.init(|| ClassWithProperties { num: 10 }).unwrap();
 
     py_run!(py, inst, "assert inst.get_num() == 10");
     py_run!(py, inst, "assert inst.get_num() == inst.DATA");
@@ -65,7 +65,7 @@ fn getter_setter_autogen() {
     let py = gil.python();
 
     let inst = py
-        .init(|_| GetterSetter {
+        .init(|| GetterSetter {
             num: 10,
             text: "Hello".to_string(),
         })

tests/test_inheritance.rs

@@ -39,7 +39,7 @@ fn subclass() {
 impl BaseClass {
     #[new]
     fn __new__(obj: &PyRawObject) -> PyResult<()> {
-        obj.init(|_| BaseClass { val1: 10 })
+        obj.init(|| BaseClass { val1: 10 })
     }
 }
 
@@ -53,7 +53,7 @@ struct SubClass {
 impl SubClass {
     #[new]
     fn __new__(obj: &PyRawObject) -> PyResult<()> {
-        obj.init(|_| SubClass { val2: 5 })?;
+        obj.init(|| SubClass { val2: 5 })?;
         BaseClass::__new__(obj)
     }
 }

tests/test_methods.rs

@@ -27,7 +27,7 @@ fn instance_method() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let obj = py.init_ref(|_| InstanceMethod { member: 42 }).unwrap();
+    let obj = py.init_ref(|| InstanceMethod { member: 42 }).unwrap();
     assert_eq!(obj.method().unwrap(), 42);
     let d = PyDict::new(py);
     d.set_item("obj", obj).unwrap();
@@ -55,7 +55,7 @@ fn instance_method_with_args() {
     let py = gil.python();
 
     let obj = py
-        .init_ref(|_| InstanceMethodWithArgs { member: 7 })
+        .init_ref(|| InstanceMethodWithArgs { member: 7 })
         .unwrap();
     assert_eq!(obj.method(6).unwrap(), 42);
     let d = PyDict::new(py);
@@ -72,7 +72,7 @@ struct ClassMethod {}
 impl ClassMethod {
     #[new]
     fn __new__(obj: &PyRawObject) -> PyResult<()> {
-        obj.init(|_| ClassMethod {})
+        obj.init(|| ClassMethod {})
     }
 
     #[classmethod]
@@ -136,7 +136,7 @@ struct StaticMethod {}
 impl StaticMethod {
     #[new]
     fn __new__(obj: &PyRawObject) -> PyResult<()> {
-        obj.init(|_| StaticMethod {})
+        obj.init(|| StaticMethod {})
     }
 
     #[staticmethod]
@@ -225,7 +225,7 @@ impl MethArgs {
 fn meth_args() {
     let gil = Python::acquire_gil();
     let py = gil.python();
-    let inst = py.init(|_| MethArgs {}).unwrap();
+    let inst = py.init(|| MethArgs {}).unwrap();
 
     py_run!(py, inst, "assert inst.get_optional() == 10");
     py_run!(py, inst, "assert inst.get_optional(100) == 100");

tests/test_various.rs

@@ -30,8 +30,8 @@ impl MutRefArg {
 fn mut_ref_arg() {
     let gil = Python::acquire_gil();
     let py = gil.python();
-    let inst1 = py.init(|_| MutRefArg { n: 0 }).unwrap();
+    let inst1 = py.init(|| MutRefArg { n: 0 }).unwrap();
-    let inst2 = py.init(|_| MutRefArg { n: 0 }).unwrap();
+    let inst2 = py.init(|| MutRefArg { n: 0 }).unwrap();
 
     let d = PyDict::new(py);
     d.set_item("inst1", &inst1).unwrap();