diff --git a/CHANGELOG.md b/CHANGELOG.md
index e580c45a..e80cdbdc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
  * `PyDict::from_sequence()`, equivalent to `dict([(key, val), ...])`
  * Bindings for the `datetime` standard library types: `PyDate`, `PyTime`, `PyDateTime`, `PyTzInfo`, `PyDelta` with associated `ffi` types, by pganssle [#200](https://github.com/PyO3/pyo3/pull/200).
  * `PyString`, `PyUnicode`, and `PyBytes` now have an `as_bytes()` method that returns `&[u8]`.
+ * `PyObjectProtocol::get_type_ptr()` by ijl in [#242](https://github.com/PyO3/pyo3/pull/242)
 
 ### Removed
  * Removed most entries from the prelude. The new prelude is small and clear.
diff --git a/pyo3-derive-backend/src/py_class.rs b/pyo3-derive-backend/src/py_class.rs
index be032b8e..784ba205 100644
--- a/pyo3-derive-backend/src/py_class.rs
+++ b/pyo3-derive-backend/src/py_class.rs
@@ -257,24 +257,6 @@ fn impl_class(
             }
         }
 
-        impl ::pyo3::ToBorrowedObject for #cls {
-            fn with_borrowed_ptr<F, R>(&self, _py: ::pyo3::Python, f: F) -> R
-                where F: FnOnce(*mut ::pyo3::ffi::PyObject) -> R
-            {
-                use ::pyo3::python::ToPyPointer;
-                f(self.as_ptr())
-            }
-        }
-
-        impl<'a> ::pyo3::ToBorrowedObject for &'a mut #cls {
-            fn with_borrowed_ptr<F, R>(&self, _py: ::pyo3::Python, f: F) -> R
-                where F: FnOnce(*mut ::pyo3::ffi::PyObject) -> R
-            {
-                use ::pyo3::python::ToPyPointer;
-                f(self.as_ptr())
-            }
-        }
-
         #extra
     }
 }
diff --git a/src/conversion.rs b/src/conversion.rs
index d1976343..da224209 100644
--- a/src/conversion.rs
+++ b/src/conversion.rs
@@ -16,6 +16,10 @@ pub trait ToPyObject {
     fn to_object(&self, py: Python) -> PyObject;
 }
 
+/// This trait has two implementations: The slow one is implemented for
+/// all [ToPyObject] and creates a new object using [ToPyObject::to_object],
+/// while the fast one is only implemented for ToPyPointer (we know
+/// that every ToPyObject is also ToPyObject) and uses [ToPyPointer::as_ptr()]
 pub trait ToBorrowedObject: ToPyObject {
     /// Converts self into a Python object and calls the specified closure
     /// on the native FFI pointer underlying the Python object.
@@ -37,6 +41,18 @@ pub trait ToBorrowedObject: ToPyObject {
 
 impl<T> ToBorrowedObject for T where T: ToPyObject {}
 
+impl<T> ToBorrowedObject for T
+where
+    T: ToPyObject + ToPyPointer,
+{
+    fn with_borrowed_ptr<F, R>(&self, _py: Python, f: F) -> R
+    where
+        F: FnOnce(*mut ffi::PyObject) -> R,
+    {
+        f(self.as_ptr())
+    }
+}
+
 /// Conversion trait that allows various objects to be converted into `PyObject`
 /// by consuming original object.
 pub trait IntoPyObject {
diff --git a/src/object.rs b/src/object.rs
index 025c5bd7..0570953d 100644
--- a/src/object.rs
+++ b/src/object.rs
@@ -258,16 +258,6 @@ impl ToPyObject for PyObject {
     }
 }
 
-impl ToBorrowedObject for PyObject {
-    #[inline]
-    fn with_borrowed_ptr<F, R>(&self, _py: Python, f: F) -> R
-    where
-        F: FnOnce(*mut ffi::PyObject) -> R,
-    {
-        f(self.as_ptr())
-    }
-}
-
 impl ToPyPointer for PyObject {
     /// Gets the underlying FFI pointer, returns a borrowed pointer.
     #[inline]
diff --git a/src/objectprotocol.rs b/src/objectprotocol.rs
index 7b5d3961..1b5e9c74 100644
--- a/src/objectprotocol.rs
+++ b/src/objectprotocol.rs
@@ -44,7 +44,7 @@ pub trait ObjectProtocol {
     /// On Python 2, this is equivalent to the Python expression `cmp(self, other)`.
     ///
     /// On Python 3, this is equivalent to:
-    /// ```python,ignore
+    /// ```python
     /// if self == other:
     ///     return Equal
     /// elif a < b:
diff --git a/src/typeob.rs b/src/typeob.rs
index 514b0025..fd43b4a9 100644
--- a/src/typeob.rs
+++ b/src/typeob.rs
@@ -72,7 +72,9 @@ pub const PY_TYPE_FLAG_DICT: usize = 1 << 3;
 /// Calling of `__new__` method of base class is developer's responsibility.
 ///
 /// Example of custom class implementation with `__new__` method:
-/// ```rust,ignore
+/// ```
+/// #![feature(specialization)]
+///
 /// use pyo3::prelude::*;
 ///
 /// #[pyclass]
@@ -84,8 +86,7 @@ pub const PY_TYPE_FLAG_DICT: usize = 1 << 3;
 /// impl MyClass {
 ///    #[new]
 ///    fn __new__(obj: &PyRawObject) -> PyResult<()> {
-///        obj.init(|token| MyClass{token: token});
-///        MyClass::BaseType::__new__(obj)
+///        obj.init(|token| MyClass { token })
 ///    }
 /// }
 /// ```
diff --git a/src/types/boolobject.rs b/src/types/boolobject.rs
index 67454e53..b48569a9 100644
--- a/src/types/boolobject.rs
+++ b/src/types/boolobject.rs
@@ -1,5 +1,5 @@
 // Copyright (c) 2017-present PyO3 Project and Contributors
-use conversion::{IntoPyObject, PyTryFrom, ToBorrowedObject, ToPyObject};
+use conversion::{IntoPyObject, PyTryFrom, ToPyObject};
 use ffi;
 use object::PyObject;
 use python::{Python, ToPyPointer};
@@ -44,23 +44,6 @@ impl ToPyObject for bool {
     }
 }
 
-impl ToBorrowedObject for bool {
-    #[inline]
-    fn with_borrowed_ptr<F, R>(&self, _py: Python, f: F) -> R
-    where
-        F: FnOnce(*mut ffi::PyObject) -> R,
-    {
-        // Avoid unnecessary Py_INCREF/Py_DECREF pair
-        f(unsafe {
-            if *self {
-                ffi::Py_True()
-            } else {
-                ffi::Py_False()
-            }
-        })
-    }
-}
-
 impl IntoPyObject for bool {
     #[inline]
     fn into_object(self, py: Python) -> PyObject {
diff --git a/src/types/mod.rs b/src/types/mod.rs
index c37cafce..53860cb5 100644
--- a/src/types/mod.rs
+++ b/src/types/mod.rs
@@ -143,16 +143,6 @@ macro_rules! pyobject_native_type_convert(
             }
         }
 
-        impl<$($type_param,)*> $crate::ToBorrowedObject for $name
-        {
-            #[inline]
-            fn with_borrowed_ptr<F, R>(&self, _py: $crate::Python, f: F) -> R
-                where F: FnOnce(*mut $crate::ffi::PyObject) -> R
-            {
-                f(self.0.as_ptr())
-            }
-        }
-
         impl<$($type_param,)*> ::std::fmt::Debug for $name {
             fn fmt(&self, f: &mut ::std::fmt::Formatter)
                    -> Result<(), ::std::fmt::Error>
diff --git a/tests/test_gc.rs b/tests/test_gc.rs
index ec0ee2e9..fbf4a533 100644
--- a/tests/test_gc.rs
+++ b/tests/test_gc.rs
@@ -52,6 +52,7 @@ fn class_with_freelist() {
 struct TestDropCall {
     drop_called: Arc<AtomicBool>,
 }
+
 impl Drop for TestDropCall {
     fn drop(&mut self) {
         self.drop_called.store(true, Ordering::Relaxed);
@@ -98,6 +99,7 @@ fn data_is_dropped() {
 struct ClassWithDrop {
     token: PyToken,
 }
+
 impl Drop for ClassWithDrop {
     fn drop(&mut self) {
         unsafe {
@@ -188,6 +190,7 @@ fn gc_integration() {
 struct GCIntegration2 {
     token: PyToken,
 }
+
 #[test]
 fn gc_integration2() {
     let gil = Python::acquire_gil();
@@ -200,6 +203,7 @@ fn gc_integration2() {
 struct WeakRefSupport {
     token: PyToken,
 }
+
 #[test]
 fn weakref_support() {
     let gil = Python::acquire_gil();
@@ -237,7 +241,7 @@ impl Drop for BaseClassWithDrop {
     }
 }
 
-#[pyclass(extends=BaseClassWithDrop)]
+#[pyclass(extends = BaseClassWithDrop)]
 struct SubClassWithDrop {
     token: PyToken,
     data: Option<Arc<AtomicBool>>,