add convenience method to PyErr and exception types

guide/src/class.md

@@ -117,13 +117,13 @@ struct BaseClass {
 #[py::class(base=BaseClass)]
 struct MyEventLoop {
     fn method2(&self) -> PyResult<()> {
-       self.get_super().method()
+       self.get_base().method()
     }
 }
 ```
 
-`ObjectProtocol` trait provide `get_super()` method. It returns reference to instance of
-parent class.
+`ObjectProtocol` trait provides `get_base()` method. It returns reference to instance of
+base class.
 
 
 ## Object properties

src/err.rs

@@ -54,10 +54,19 @@ macro_rules! py_exception {
             }
         }
 
+        impl<T> std::convert::Into<$crate::PyResult<T>> for $name {
+            fn into(self) -> $crate::PyResult<T> {
+                $crate::PyErr::new::<$name, _>(()).into()
+            }
+        }
+
         impl $name {
             pub fn new<T: $crate::ToPyObject + 'static>(args: T) -> $crate::PyErr {
                 $crate::PyErr::new::<$name, T>(args)
             }
+            pub fn into<R, T: $crate::ToPyObject + 'static>(args: T) -> $crate::PyResult<R> {
+                $crate::PyErr::new::<$name, T>(args).into()
+            }
             #[inline]
             fn type_object() -> *mut $crate::ffi::PyTypeObject {
                 static mut TYPE_OBJECT: *mut $crate::ffi::PyTypeObject =
@@ -457,6 +466,13 @@ impl std::convert::From<PyErr> for std::io::Error {
     }
 }
 
+/// Convert `PyErr` to `PyResult<T>`
+impl<T> std::convert::Into<PyResult<T>> for PyErr {
+    fn into(self) -> PyResult<T> {
+        Err(self)
+    }
+}
+
 macro_rules! impl_to_pyerr {
     ($err: ty, $pyexc: ty) => {
         impl PyErrArguments for $err {

src/objects/exc.rs

@@ -1,6 +1,4 @@
 // Copyright (c) 2017-present PyO3 Project and Contributors
-//
-// based on Daniel Grunwald's https://github.com/dgrunwald/rust-cpython
 
 //! This module contains the standard python exception types.
 
@@ -25,10 +23,18 @@ macro_rules! exc_type(
                 PyErr::new::<$name, _>(())
             }
         }
+        impl<T> std::convert::Into<$crate::PyResult<T>> for $name {
+            fn into(self) -> $crate::PyResult<T> {
+                PyErr::new::<$name, _>(()).into()
+            }
+        }
         impl $name {
             pub fn new<V: ToPyObject + 'static>(args: V) -> PyErr {
                 PyErr::new::<$name, V>(args)
             }
+            pub fn into<R, V: ToPyObject + 'static>(args: V) -> PyResult<R> {
+                PyErr::new::<$name, V>(args).into()
+            }
         }
         impl PyTypeObject for $name {
             #[inline(always)]

src/objects/exc_impl.rs

@@ -39,12 +39,23 @@ macro_rules! import_exception {
             }
         }
 
+        impl<T> ::std::convert::Into<$crate::PyResult<T>> for $name {
+            fn into(self) -> $crate::PyResult<T> {
+                $crate::PyErr::new::<$name, _>(()).into()
+            }
+        }
+
         impl $name {
             pub fn new<T: $crate::ToPyObject + 'static>(args: T) -> $crate::PyErr
                 where Self: $crate::typeob::PyTypeObject + Sized
             {
                 $crate::PyErr::new::<Self, T>(args)
             }
+            pub fn into<R, T: $crate::ToPyObject + 'static>(args: T) -> $crate::PyResult<R>
+                where Self: $crate::typeob::PyTypeObject + Sized
+            {
+                $crate::PyErr::new::<Self, T>(args).into()
+            }
         }
 
         impl $crate::typeob::PyTypeObject for $name {

src/typeob.rs

@@ -115,8 +115,6 @@ impl<T> PyObjectAlloc<T> for T where T : PyTypeInfo {
         T::init_type();
 
         let obj = ffi::PyType_GenericAlloc(T::type_object(), 0);
-        println!("ALLOC {:?} {:?}", obj, ffi::Py_REFCNT(obj));
-
         let ptr = (obj as *mut u8).offset(T::OFFSET) as *mut T;
         std::ptr::write(ptr, value);