nicer code separation, cleanup logic, std::function type caster

example/example2.cpp

@@ -9,6 +9,7 @@
 */
 
 #include "example.h"
+#include <pybind/stl.h>
 
 class Example2 {
 public:

example/example5.cpp

@@ -9,6 +9,7 @@
 */
 
 #include "example.h"
+#include <pybind/functional.h>
 
 
 class Pet {
@@ -73,6 +74,14 @@ void test_callback3(Example5 *ex, int value) {
     ex->callback(value);
 }
 
+void test_callback4(const std::function<int(int)> &func) {
+    cout << "func(43) = " << func(43)<< std::endl;
+}
+
+std::function<int(int)> test_callback5() {
+    return [](int i) { return i+1; };
+}
+
 void init_ex5(py::module &m) {
     py::class_<Pet> pet_class(m, "Pet");
     pet_class
@@ -89,6 +98,8 @@ void init_ex5(py::module &m) {
     m.def("test_callback1", &test_callback1);
     m.def("test_callback2", &test_callback2);
     m.def("test_callback3", &test_callback3);
+    m.def("test_callback4", &test_callback4);
+    m.def("test_callback5", &test_callback5);
 
     py::class_<Example5>(m, "Example5")
         .def(py::init<py::object, int>());

example/example5.py

@@ -22,6 +22,8 @@ except Exception as e:
 from example import test_callback1
 from example import test_callback2
 from example import test_callback3
+from example import test_callback4
+from example import test_callback5
 from example import Example5
 
 def func1():
@@ -43,3 +45,7 @@ print(test_callback2(func2))
 
 callback = MyCallback(3)
 test_callback3(callback, 4)
+
+test_callback4(lambda i: i+1)
+f = test_callback5()
+print("func(43) = %i" % f(43))