pybind11/example/example-callbacks.cpp
Jason Rhinelander b3f3d79f4c Rename examples files, as per #288
This renames example files from `exampleN` to `example-description`.

Specifically, the following renaming is applied:

example1 -> example-methods-and-attributes
example2 -> example-python-types
example3 -> example-operator-overloading
example4 -> example-constants-and-functions
example5 -> example-callbacks (*)
example6 -> example-sequence-and-iterators
example7 -> example-buffers
example8 -> example-custom-ref-counting
example9 -> example-modules
example10 -> example-numpy-vectorize
example11 -> example-arg-keywords-and-defaults
example12 -> example-virtual-functions
example13 -> example-keep-alive
example14 -> example-opaque-types
example15 -> example-pickling
example16 -> example-inheritance
example17 -> example-stl-binders
example18 -> example-eval
example19 -> example-custom-exceptions

* the inheritance parts of example5 are moved into example-inheritance
(previously example16), and the remainder is left as example-callbacks.

This commit also renames the internal variables ("Example1",
"Example2", "Example4", etc.) into non-numeric names ("ExampleMandA",
"ExamplePythonTypes", "ExampleWithEnum", etc.) to correspond to the
file renaming.

The order of tests is preserved, but this can easily be changed if
there is some more natural ordering by updating the list in
examples/CMakeLists.txt.
2016-07-18 16:43:18 -04:00

98 lines
2.8 KiB
C++

/*
example/example-callbacks.cpp -- callbacks
Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
All rights reserved. Use of this source code is governed by a
BSD-style license that can be found in the LICENSE file.
*/
#include "example.h"
#include <pybind11/functional.h>
bool test_callback1(py::object func) {
func();
return false;
}
int test_callback2(py::object func) {
py::object result = func("Hello", 'x', true, 5);
return result.cast<int>();
}
void test_callback3(const std::function<int(int)> &func) {
cout << "func(43) = " << func(43)<< std::endl;
}
std::function<int(int)> test_callback4() {
return [](int i) { return i+1; };
}
py::cpp_function test_callback5() {
return py::cpp_function([](int i) { return i+1; },
py::arg("number"));
}
int dummy_function(int i) { return i + 1; }
int dummy_function2(int i, int j) { return i + j; }
std::function<int(int)> roundtrip(std::function<int(int)> f) {
std::cout << "roundtrip.." << std::endl;
return f;
}
void test_dummy_function(const std::function<int(int)> &f) {
using fn_type = int (*)(int);
auto result = f.target<fn_type>();
if (!result) {
std::cout << "could not convert to a function pointer." << std::endl;
auto r = f(1);
std::cout << "eval(1) = " << r << std::endl;
} else if (*result == dummy_function) {
std::cout << "argument matches dummy_function" << std::endl;
auto r = (*result)(1);
std::cout << "eval(1) = " << r << std::endl;
} else {
std::cout << "argument does NOT match dummy_function. This should never happen!" << std::endl;
}
}
void init_ex_callbacks(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);
/* Test cleanup of lambda closure */
struct Payload {
Payload() {
std::cout << "Payload constructor" << std::endl;
}
~Payload() {
std::cout << "Payload destructor" << std::endl;
}
Payload(const Payload &) {
std::cout << "Payload copy constructor" << std::endl;
}
Payload(Payload &&) {
std::cout << "Payload move constructor" << std::endl;
}
};
m.def("test_cleanup", []() -> std::function<void(void)> {
Payload p;
return [p]() {
/* p should be cleaned up when the returned function is garbage collected */
};
});
/* Test if passing a function pointer from C++ -> Python -> C++ yields the original pointer */
m.def("dummy_function", &dummy_function);
m.def("dummy_function2", &dummy_function2);
m.def("roundtrip", &roundtrip);
m.def("test_dummy_function", &test_dummy_function);
}