test_callbacks.cpp revision 11986:c12e4625ab56 
1/*
2    tests/test_callbacks.cpp -- callbacks
3
4    Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
5
6    All rights reserved. Use of this source code is governed by a
7    BSD-style license that can be found in the LICENSE file.
8*/
9
10#include "pybind11_tests.h"
11#include "constructor_stats.h"
12#include <pybind11/functional.h>
13
14
15py::object test_callback1(py::object func) {
16    return func();
17}
18
19py::tuple test_callback2(py::object func) {
20    return func("Hello", 'x', true, 5);
21}
22
23std::string test_callback3(const std::function<int(int)> &func) {
24    return "func(43) = " + std::to_string(func(43));
25}
26
27std::function<int(int)> test_callback4() {
28    return [](int i) { return i+1; };
29}
30
31py::cpp_function test_callback5() {
32    return py::cpp_function([](int i) { return i+1; },
33       py::arg("number"));
34}
35
36int dummy_function(int i) { return i + 1; }
37int dummy_function2(int i, int j) { return i + j; }
38std::function<int(int)> roundtrip(std::function<int(int)> f, bool expect_none = false) {
39    if (expect_none && f) {
40        throw std::runtime_error("Expected None to be converted to empty std::function");
41    }
42    return f;
43}
44
45std::string test_dummy_function(const std::function<int(int)> &f) {
46    using fn_type = int (*)(int);
47    auto result = f.target<fn_type>();
48    if (!result) {
49        auto r = f(1);
50        return "can't convert to function pointer: eval(1) = " + std::to_string(r);
51    } else if (*result == dummy_function) {
52        auto r = (*result)(1);
53        return "matches dummy_function: eval(1) = " + std::to_string(r);
54    } else {
55        return "argument does NOT match dummy_function. This should never happen!";
56    }
57}
58
59struct Payload {
60    Payload() {
61        print_default_created(this);
62    }
63    ~Payload() {
64        print_destroyed(this);
65    }
66    Payload(const Payload &) {
67        print_copy_created(this);
68    }
69    Payload(Payload &&) {
70        print_move_created(this);
71    }
72};
73
74/// Something to trigger a conversion error
75struct Unregistered {};
76
77test_initializer callbacks([](py::module &m) {
78    m.def("test_callback1", &test_callback1);
79    m.def("test_callback2", &test_callback2);
80    m.def("test_callback3", &test_callback3);
81    m.def("test_callback4", &test_callback4);
82    m.def("test_callback5", &test_callback5);
83
84    // Test keyword args and generalized unpacking
85    m.def("test_tuple_unpacking", [](py::function f) {
86        auto t1 = py::make_tuple(2, 3);
87        auto t2 = py::make_tuple(5, 6);
88        return f("positional", 1, *t1, 4, *t2);
89    });
90
91    m.def("test_dict_unpacking", [](py::function f) {
92        auto d1 = py::dict("key"_a="value", "a"_a=1);
93        auto d2 = py::dict();
94        auto d3 = py::dict("b"_a=2);
95        return f("positional", 1, **d1, **d2, **d3);
96    });
97
98    m.def("test_keyword_args", [](py::function f) {
99        return f("x"_a=10, "y"_a=20);
100    });
101
102    m.def("test_unpacking_and_keywords1", [](py::function f) {
103        auto args = py::make_tuple(2);
104        auto kwargs = py::dict("d"_a=4);
105        return f(1, *args, "c"_a=3, **kwargs);
106    });
107
108    m.def("test_unpacking_and_keywords2", [](py::function f) {
109        auto kwargs1 = py::dict("a"_a=1);
110        auto kwargs2 = py::dict("c"_a=3, "d"_a=4);
111        return f("positional", *py::make_tuple(1), 2, *py::make_tuple(3, 4), 5,
112                 "key"_a="value", **kwargs1, "b"_a=2, **kwargs2, "e"_a=5);
113    });
114
115    m.def("test_unpacking_error1", [](py::function f) {
116        auto kwargs = py::dict("x"_a=3);
117        return f("x"_a=1, "y"_a=2, **kwargs); // duplicate ** after keyword
118    });
119
120    m.def("test_unpacking_error2", [](py::function f) {
121        auto kwargs = py::dict("x"_a=3);
122        return f(**kwargs, "x"_a=1); // duplicate keyword after **
123    });
124
125    m.def("test_arg_conversion_error1", [](py::function f) {
126        f(234, Unregistered(), "kw"_a=567);
127    });
128
129    m.def("test_arg_conversion_error2", [](py::function f) {
130        f(234, "expected_name"_a=Unregistered(), "kw"_a=567);
131    });
132
133    /* Test cleanup of lambda closure */
134    m.def("test_cleanup", []() -> std::function<void(void)> {
135        Payload p;
136
137        return [p]() {
138            /* p should be cleaned up when the returned function is garbage collected */
139        };
140    });
141
142    /* Test if passing a function pointer from C++ -> Python -> C++ yields the original pointer */
143    m.def("dummy_function", &dummy_function);
144    m.def("dummy_function2", &dummy_function2);
145    m.def("roundtrip", &roundtrip, py::arg("f"), py::arg("expect_none")=false);
146    m.def("test_dummy_function", &test_dummy_function);
147    // Export the payload constructor statistics for testing purposes:
148    m.def("payload_cstats", &ConstructorStats::get<Payload>);
149});
150