Make the init methods use a value instead of a function

CHANGELOG.md

@@ -15,6 +15,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
  * Renamed `add_function` to `add_wrapped` as it now also supports modules.
  * Renamed `#[pymodinit]` to `#[pymodule]`.
+ * `init`, `init_ref` and `init_mut` now take a value instead of a function that returns the value. (Migrating normally just removing `||`)
  * Renamed `py_exception` to `create_exception` and refactored the error macros.
  * Renamed `wrap_function!` to `wrap_pyfunction!`
  * Migrated to the 2018 edition

examples/rustapi_module/src/datetime.rs

@@ -191,7 +191,7 @@ 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/dict_iter.rs

@@ -17,7 +17,7 @@ pub struct DictSize {
 impl DictSize {
     #[new]
     fn __new__(obj: &PyRawObject, expected: u32) -> PyResult<()> {
-        obj.init(|| DictSize { expected })
+        obj.init(DictSize { expected })
     }
 
     fn iter_dict(&mut self, _py: Python<'_>, dict: &PyDict) -> PyResult<u32> {

examples/rustapi_module/src/othermod.rs

@@ -14,7 +14,7 @@ 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

@@ -17,7 +17,7 @@ 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

@@ -42,7 +42,7 @@ struct MyClass {
 }
 let gil = Python::acquire_gil();
 let py = gil.python();
-let obj = PyRef::new(py, || MyClass { num: 3, debug: true }).unwrap();
+let obj = PyRef::new(py, MyClass { num: 3, debug: true }).unwrap();
 assert_eq!(obj.num, 3);
 let dict = PyDict::new();
 // You can treat a `PyRef` as a Python object
@@ -60,7 +60,7 @@ struct MyClass {
 }
 let gil = Python::acquire_gil();
 let py = gil.python();
-let mut obj = PyRefMut::new(py, || MyClass { num: 3, debug: true }).unwrap();
+let mut obj = PyRefMut::new(py, MyClass { num: 3, debug: true }).unwrap();
 obj.num = 5;
 ```
 
@@ -119,7 +119,7 @@ impl MyClass {
 
      #[new]
      fn __new__(obj: &PyRawObject, num: i32) -> PyResult<()> {
-         obj.init(||   {
+         obj.init({
              MyClass {
                  num,
              }
@@ -159,7 +159,7 @@ struct BaseClass {
 impl BaseClass {
    #[new]
    fn __new__(obj: &PyRawObject) -> PyResult<()> {
-       obj.init(||   BaseClass{ val1: 10 })
+       Ok(obj.init(BaseClass{ val1: 10 }))
    }
 
    pub fn method(&self) -> PyResult<()> {
@@ -176,7 +176,7 @@ 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

@@ -37,7 +37,7 @@ struct MyClass {
 impl MyClass {
     #[new]
     fn __new__(obj: &PyRawObject, num: u32) -> PyResult<()> {
-        obj.init(|| {
+        obj.init({
             MyClass {
                 num,
             }

pyo3-derive-backend/src/func.rs

@@ -130,7 +130,7 @@ pub fn impl_method_proto(
                 });
 
                 let tmp2 = extract_decl(syn::parse_quote! {
-                    fn test( &self, arg: Option<<#cls as #p<'p>>::#arg_name>) -> <#cls as #p<'p>>::Result {}
+                    fn test(&self, arg: Option<<#cls as #p<'p>>::#arg_name>) -> <#cls as #p<'p>>::Result {}
                 });
 
                 modify_arg_ty(sig, 1, &tmp, &tmp2);

pyo3-derive-backend/src/py_class.rs

@@ -201,12 +201,9 @@ fn impl_class(
             }
         }
 
-        // TBH I'm not sure what exactely this does and I'm sure there's a better way,
-        // but for now it works and it only safe code and it is required to return custom
-        // 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)
             }
         }
 

src/instance.rs

@@ -52,7 +52,7 @@ pub trait PyNativeType: PyObjectWithGIL {}
 /// }
 /// let gil = Python::acquire_gil();
 /// let py = gil.python();
-/// let obj = PyRef::new(gil.python(), || Point { x: 3, y: 4 }).unwrap();
+/// let obj = PyRef::new(gil.python(), Point { x: 3, y: 4 }).unwrap();
 /// let d = vec![("p", obj)].into_py_dict(py);
 /// py.run("assert p.length() == 12", None, Some(d)).unwrap();
 /// ```
@@ -69,12 +69,9 @@ impl<'a, T> PyRef<'a, T>
 where
     T: PyTypeInfo + PyTypeObject + PyTypeCreate,
 {
-    pub fn new<F>(py: Python, f: F) -> PyResult<PyRef<T>>
-    where
-        F: FnOnce() -> T,
-    {
+    pub fn new(py: Python, value: T) -> PyResult<PyRef<T>> {
         let obj = T::create(py)?;
-        obj.init(f)?;
+        obj.init(value)?;
         let ref_ = unsafe { py.from_owned_ptr(obj.into_ptr()) };
         Ok(PyRef::from_ref(ref_))
     }
@@ -117,7 +114,7 @@ impl<'a, T: PyTypeInfo> Deref for PyRef<'a, T> {
 /// }
 /// let gil = Python::acquire_gil();
 /// let py = gil.python();
-/// let mut obj = PyRefMut::new(gil.python(), || Point { x: 3, y: 4 }).unwrap();
+/// let mut obj = PyRefMut::new(gil.python(), Point { x: 3, y: 4 }).unwrap();
 /// let d = vec![("p", obj.to_object(py))].into_py_dict(py);
 /// obj.x = 5; obj.y = 20;
 /// py.run("assert p.length() == 100", None, Some(d)).unwrap();
@@ -135,12 +132,9 @@ impl<'a, T> PyRefMut<'a, T>
 where
     T: PyTypeInfo + PyTypeObject + PyTypeCreate,
 {
-    pub fn new<F>(py: Python, f: F) -> PyResult<PyRefMut<T>>
-    where
-        F: FnOnce() -> T,
-    {
+    pub fn new(py: Python, value: T) -> PyResult<PyRefMut<T>> {
         let obj = T::create(py)?;
-        obj.init(f)?;
+        obj.init(value)?;
         let ref_ = unsafe { py.mut_from_owned_ptr(obj.into_ptr()) };
         Ok(PyRefMut::from_mut(ref_))
     }
@@ -350,17 +344,40 @@ where
 {
     /// Create new instance of T and move it under python management
     /// Returns `Py<T>`.
-    pub fn new<F>(py: Python, f: F) -> PyResult<Py<T>>
+    pub fn new(py: Python, value: T) -> PyResult<Py<T>>
     where
-        F: FnOnce() -> T,
         T: PyTypeObject + PyTypeInfo,
     {
         let ob = <T as PyTypeCreate>::create(py)?;
-        ob.init(f)?;
+        ob.init(value)?;
 
         let ob = unsafe { Py::from_owned_ptr(ob.into_ptr()) };
         Ok(ob)
     }
+
+    /// Create new instance of `T` and move it under python management.
+    /// Returns references to `T`
+    pub fn new_ref(py: Python, value: T) -> PyResult<&T>
+    where
+        T: PyTypeObject + PyTypeInfo,
+    {
+        let ob = <T as PyTypeCreate>::create(py)?;
+        ob.init(value)?;
+
+        unsafe { Ok(py.from_owned_ptr(ob.into_ptr())) }
+    }
+
+    /// Create new instance of `T` and move it under python management.
+    /// Returns mutable references to `T`
+    pub fn new_mut(py: Python, value: T) -> PyResult<&mut T>
+    where
+        T: PyTypeObject + PyTypeInfo,
+    {
+        let ob = <T as PyTypeCreate>::create(py)?;
+        ob.init(value)?;
+
+        unsafe { Ok(py.mut_from_owned_ptr(ob.into_ptr())) }
+    }
 }
 
 /// Specialization workaround

src/python.rs

@@ -250,34 +250,31 @@ impl<'p> Python<'p> {
     /// Create new instance of `T` and move it under python management.
     /// Returns `Py<T>`.
     #[inline]
-    pub fn init<T, F>(self, f: F) -> PyResult<Py<T>>
+    pub fn init<T>(self, value: T) -> PyResult<Py<T>>
     where
-        F: FnOnce() -> T,
         T: PyTypeCreate,
     {
-        Py::new(self, f)
+        Py::new(self, value)
     }
 
     /// Create new instance of `T` and move it under python management.
     /// Created object get registered in release pool. Returns references to `T`
     #[inline]
-    pub fn init_ref<T, F>(self, f: F) -> PyResult<PyRef<'p, T>>
+    pub fn init_ref<T>(self, value: T) -> PyResult<PyRef<'p, T>>
     where
-        F: FnOnce() -> T,
         T: PyTypeCreate,
     {
-        PyRef::new(self, f)
+        PyRef::new(self, value)
     }
 
     /// Create new instance of `T` and move it under python management.
     /// Created object get registered in release pool. Returns mutable references to `T`
     #[inline]
-    pub fn init_mut<T, F>(self, f: F) -> PyResult<PyRefMut<'p, T>>
+    pub fn init_mut<T>(self, value: T) -> PyResult<PyRefMut<'p, T>>
     where
-        F: FnOnce() -> T,
         T: PyTypeCreate,
     {
-        PyRefMut::new(self, f)
+        PyRefMut::new(self, value)
     }
 }
 

src/typeob.rs

@@ -83,7 +83,7 @@ pub const PY_TYPE_FLAG_DICT: usize = 1 << 3;
 /// impl MyClass {
 ///    #[new]
 ///    fn __new__(obj: &PyRawObject) -> PyResult<()> {
-///        obj.init(|| MyClass { })
+///        obj.init(MyClass { })
 ///    }
 /// }
 /// ```
@@ -139,13 +139,10 @@ impl PyRawObject {
         }
     }
 
-    pub fn init<T, F>(&self, f: F) -> PyResult<()>
+    pub fn init<T>(&self, value: T) -> PyResult<()>
     where
-        F: FnOnce() -> T,
         T: PyTypeInfo,
     {
-        let value = f();
-
         unsafe {
             // The `as *mut u8` part is required because the offset is in bytes
             let ptr = (self.ptr as *mut u8).offset(T::OFFSET) as *mut T;

src/types/tuple.rs

@@ -199,7 +199,7 @@ macro_rules! tuple_conversion ({$length:expr,$(($refN:ident, $n:tt, $T:ident)),+
             let slice = t.as_slice();
             if t.len() == $length {
                 Ok((
-                    $( slice[$n].extract::<$T>(obj.py())?, )+
+                    $(slice[$n].extract::<$T>(obj.py())?,)+
                 ))
             } else {
                 Err(wrong_tuple_length(t, $length))

tests/test_arithmetics.rs

@@ -32,7 +32,7 @@ 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'");
@@ -110,7 +110,7 @@ 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);
     };
 
@@ -164,7 +164,7 @@ 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'");
@@ -230,7 +230,7 @@ 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'");
@@ -257,7 +257,7 @@ 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

@@ -66,7 +66,7 @@ fn test_buffer() {
     let py = gil.python();
 
     let t = py
-        .init(|| TestClass {
+        .init(TestClass {
             vec: vec![b' ', b'2', b'3'],
         })
         .unwrap();
@@ -83,7 +83,7 @@ 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

@@ -8,7 +8,7 @@ struct EmptyClassWithNew {}
 impl EmptyClassWithNew {
     #[__new__]
     fn __new__(obj: &PyRawObject) -> PyResult<()> {
-        obj.init(|| EmptyClassWithNew {})
+        obj.init(EmptyClassWithNew {})
     }
 }
 
@@ -33,7 +33,7 @@ struct NewWithOneArg {
 impl NewWithOneArg {
     #[new]
     fn __new__(obj: &PyRawObject, arg: i32) -> PyResult<()> {
-        obj.init(|| NewWithOneArg { _data: arg })
+        obj.init(NewWithOneArg { _data: arg })
     }
 }
 
@@ -57,7 +57,7 @@ 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

@@ -31,16 +31,19 @@ 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 {
-        l: (isize::MAX as usize) + 1,
-    })
+    let inst = Py::new(
+        py,
+        Len {
+            l: (isize::MAX as usize) + 1,
+        },
+    )
     .unwrap();
     py_expect_exception!(py, inst, "len(inst)", OverflowError);
 }
@@ -66,9 +69,12 @@ fn iterator() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let inst = Py::new(py, || Iterator {
-        iter: Box::new(5..8),
-    })
+    let inst = Py::new(
+        py,
+        Iterator {
+            iter: Box::new(5..8),
+        },
+    )
     .unwrap();
     py_assert!(py, inst, "iter(inst) is inst");
     py_assert!(py, inst, "list(inst) == [5, 6, 7]");
@@ -108,7 +114,7 @@ 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)'");
@@ -121,7 +127,7 @@ 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'");
@@ -148,10 +154,10 @@ fn comparisons() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let zero = Py::new(py, || Comparisons { val: 0 }).unwrap();
-    let one = Py::new(py, || Comparisons { val: 1 }).unwrap();
-    let ten = Py::new(py, || Comparisons { val: 10 }).unwrap();
-    let minus_one = Py::new(py, || Comparisons { val: -1 }).unwrap();
+    let zero = Py::new(py, Comparisons { val: 0 }).unwrap();
+    let one = Py::new(py, Comparisons { val: 1 }).unwrap();
+    let ten = Py::new(py, Comparisons { val: 10 }).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");
@@ -182,7 +188,7 @@ 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);
 }
@@ -203,11 +209,11 @@ 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)");
 }
 
@@ -231,7 +237,7 @@ 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);
@@ -256,7 +262,7 @@ 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);
@@ -285,7 +291,7 @@ 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]");
@@ -307,7 +313,7 @@ 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'");
 }
 
@@ -326,7 +332,7 @@ 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);
@@ -364,9 +370,7 @@ fn context_manager() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let mut c = py
-        .init_mut(|| ContextManager { exit_called: false })
-        .unwrap();
+    let mut c = py.init_mut(ContextManager { exit_called: false }).unwrap();
     py_run!(py, c, "with c as x: assert x == 42");
     assert!(c.exit_called);
 
@@ -423,7 +427,7 @@ 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();
 
@@ -439,7 +443,7 @@ struct DunderDictSupport {}
 fn dunder_dict_support() {
     let gil = Python::acquire_gil();
     let py = gil.python();
-    let inst = PyRef::new(py, || DunderDictSupport {}).unwrap();
+    let inst = PyRef::new(py, DunderDictSupport {}).unwrap();
     py_run!(
         py,
         inst,
@@ -457,7 +461,7 @@ struct WeakRefDunderDictSupport {}
 fn weakref_dunder_dict_support() {
     let gil = Python::acquire_gil();
     let py = gil.python();
-    let inst = PyRef::new(py, || WeakRefDunderDictSupport {}).unwrap();
+    let inst = PyRef::new(py, WeakRefDunderDictSupport {}).unwrap();
     py_run!(
         py,
         inst,

tests/test_gc.rs

@@ -24,8 +24,8 @@ fn class_with_freelist() {
         let gil = Python::acquire_gil();
         let py = gil.python();
 
-        let inst = Py::new(py, || ClassWithFreelist {}).unwrap();
-        let _inst2 = Py::new(py, || ClassWithFreelist {}).unwrap();
+        let inst = Py::new(py, ClassWithFreelist {}).unwrap();
+        let _inst2 = Py::new(py, ClassWithFreelist {}).unwrap();
         ptr = inst.as_ptr();
         drop(inst);
     }
@@ -34,10 +34,10 @@ 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())
     }
 }
@@ -68,7 +68,7 @@ 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),
                 },
@@ -114,7 +114,7 @@ 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);
     }
 
@@ -157,12 +157,15 @@ fn gc_integration() {
     {
         let gil = Python::acquire_gil();
         let py = gil.python();
-        let inst = PyRef::new(py, || GCIntegration {
-            self_ref: RefCell::new(py.None()),
-            dropped: TestDropCall {
-                drop_called: Arc::clone(&drop_called),
+        let inst = PyRef::new(
+            py,
+            GCIntegration {
+                self_ref: RefCell::new(py.None()),
+                dropped: TestDropCall {
+                    drop_called: Arc::clone(&drop_called),
+                },
             },
-        })
+        )
         .unwrap();
 
         *inst.self_ref.borrow_mut() = inst.to_object(py);
@@ -183,7 +186,7 @@ fn gc_integration2() {
     let py = gil.python();
     // Temporarily disable pythons garbage collector to avoid a race condition
     py.run("import gc; gc.disable()", None, None).unwrap();
-    let inst = PyRef::new(py, || GCIntegration2 {}).unwrap();
+    let inst = PyRef::new(py, GCIntegration2 {}).unwrap();
     py_run!(py, inst, "assert inst in gc.get_objects()");
     py.run("gc.enable()", None, None).unwrap();
 }
@@ -195,7 +198,7 @@ struct WeakRefSupport {}
 fn weakref_support() {
     let gil = Python::acquire_gil();
     let py = gil.python();
-    let inst = PyRef::new(py, || WeakRefSupport {}).unwrap();
+    let inst = PyRef::new(py, WeakRefSupport {}).unwrap();
     py_run!(
         py,
         inst,
@@ -212,7 +215,7 @@ struct BaseClassWithDrop {
 impl BaseClassWithDrop {
     #[new]
     fn __new__(obj: &PyRawObject) -> PyResult<()> {
-        obj.init(|| BaseClassWithDrop { data: None })
+        obj.init(BaseClassWithDrop { data: None })
     }
 }
 
@@ -233,7 +236,7 @@ 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

@@ -31,7 +31,7 @@ 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");
@@ -61,7 +61,7 @@ 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

@@ -35,7 +35,7 @@ fn subclass() {
 impl BaseClass {
     #[new]
     fn __new__(obj: &PyRawObject) -> PyResult<()> {
-        obj.init(|| BaseClass { val1: 10 })
+        obj.init(BaseClass { val1: 10 })
     }
 }
 
@@ -49,7 +49,7 @@ 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

@@ -23,7 +23,7 @@ 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();
@@ -50,9 +50,7 @@ fn instance_method_with_args() {
     let gil = Python::acquire_gil();
     let py = gil.python();
 
-    let obj = py
-        .init_ref(|| InstanceMethodWithArgs { member: 7 })
-        .unwrap();
+    let obj = py.init_ref(InstanceMethodWithArgs { member: 7 }).unwrap();
     assert_eq!(obj.method(6).unwrap(), 42);
     let d = PyDict::new(py);
     d.set_item("obj", obj).unwrap();
@@ -68,7 +66,7 @@ struct ClassMethod {}
 impl ClassMethod {
     #[new]
     fn __new__(obj: &PyRawObject) -> PyResult<()> {
-        obj.init(|| ClassMethod {})
+        obj.init(ClassMethod {})
     }
 
     #[classmethod]
@@ -132,7 +130,7 @@ struct StaticMethod {}
 impl StaticMethod {
     #[new]
     fn __new__(obj: &PyRawObject) -> PyResult<()> {
-        obj.init(|| StaticMethod {})
+        obj.init(StaticMethod {})
     }
 
     #[staticmethod]
@@ -221,7 +219,7 @@ 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

@@ -26,8 +26,8 @@ impl MutRefArg {
 fn mut_ref_arg() {
     let gil = Python::acquire_gil();
     let py = gil.python();
-    let inst1 = py.init(|| MutRefArg { n: 0 }).unwrap();
-    let inst2 = py.init(|| MutRefArg { n: 0 }).unwrap();
+    let inst1 = 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();