1 /*
2     tests/test_stl.cpp -- STL type casters
3 
4     Copyright (c) 2017 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/stl.h>
13 
14 #include <vector>
15 #include <string>
16 
17 // Test with `std::variant` in C++17 mode, or with `boost::variant` in C++11/14
18 #if defined(PYBIND11_HAS_VARIANT)
19 using std::variant;
20 #elif defined(PYBIND11_TEST_BOOST) && (!defined(_MSC_VER) || _MSC_VER >= 1910)
21 #  include <boost/variant.hpp>
22 #  define PYBIND11_HAS_VARIANT 1
23 using boost::variant;
24 
25 namespace pybind11 { namespace detail {
26 template <typename... Ts>
27 struct type_caster<boost::variant<Ts...>> : variant_caster<boost::variant<Ts...>> {};
28 
29 template <>
30 struct visit_helper<boost::variant> {
31     template <typename... Args>
callpybind11::detail::visit_helper32     static auto call(Args &&...args) -> decltype(boost::apply_visitor(args...)) {
33         return boost::apply_visitor(args...);
34     }
35 };
36 }} // namespace pybind11::detail
37 #endif
38 
39 PYBIND11_MAKE_OPAQUE(std::vector<std::string, std::allocator<std::string>>);
40 
41 /// Issue #528: templated constructor
42 struct TplCtorClass {
TplCtorClassTplCtorClass43     template <typename T> TplCtorClass(const T &) { }
operator ==TplCtorClass44     bool operator==(const TplCtorClass &) const { return true; }
45 };
46 
47 namespace std {
48     template <>
operator ()std::hash49     struct hash<TplCtorClass> { size_t operator()(const TplCtorClass &) const { return 0; } };
50 } // namespace std
51 
52 
53 template <template <typename> class OptionalImpl, typename T>
54 struct OptionalHolder
55 {
56     OptionalHolder() = default;
member_initializedOptionalHolder57     bool member_initialized() const {
58         return member && member->initialized;
59     }
60     OptionalImpl<T> member = T{};
61 };
62 
63 
TEST_SUBMODULE(stl,m)64 TEST_SUBMODULE(stl, m) {
65     // test_vector
66     m.def("cast_vector", []() { return std::vector<int>{1}; });
67     m.def("load_vector", [](const std::vector<int> &v) { return v.at(0) == 1 && v.at(1) == 2; });
68     // `std::vector<bool>` is special because it returns proxy objects instead of references
69     m.def("cast_bool_vector", []() { return std::vector<bool>{true, false}; });
70     m.def("load_bool_vector", [](const std::vector<bool> &v) {
71         return v.at(0) == true && v.at(1) == false;
72     });
73     // Unnumbered regression (caused by #936): pointers to stl containers aren't castable
74     static std::vector<RValueCaster> lvv{2};
75     m.def("cast_ptr_vector", []() { return &lvv; });
76 
77     // test_deque
78     m.def("cast_deque", []() { return std::deque<int>{1}; });
79     m.def("load_deque", [](const std::deque<int> &v) { return v.at(0) == 1 && v.at(1) == 2; });
80 
81     // test_array
82     m.def("cast_array", []() { return std::array<int, 2> {{1 , 2}}; });
83     m.def("load_array", [](const std::array<int, 2> &a) { return a[0] == 1 && a[1] == 2; });
84 
85     // test_valarray
86     m.def("cast_valarray", []() { return std::valarray<int>{1, 4, 9}; });
87     m.def("load_valarray", [](const std::valarray<int>& v) {
88         return v.size() == 3 && v[0] == 1 && v[1] == 4 && v[2] == 9;
89     });
90 
91     // test_map
92     m.def("cast_map", []() { return std::map<std::string, std::string>{{"key", "value"}}; });
93     m.def("load_map", [](const std::map<std::string, std::string> &map) {
94         return map.at("key") == "value" && map.at("key2") == "value2";
95     });
96 
97     // test_set
98     m.def("cast_set", []() { return std::set<std::string>{"key1", "key2"}; });
99     m.def("load_set", [](const std::set<std::string> &set) {
100         return set.count("key1") && set.count("key2") && set.count("key3");
101     });
102 
103     // test_recursive_casting
104     m.def("cast_rv_vector", []() { return std::vector<RValueCaster>{2}; });
105     m.def("cast_rv_array", []() { return std::array<RValueCaster, 3>(); });
106     // NB: map and set keys are `const`, so while we technically do move them (as `const Type &&`),
107     // casters don't typically do anything with that, which means they fall to the `const Type &`
108     // caster.
109     m.def("cast_rv_map", []() { return std::unordered_map<std::string, RValueCaster>{{"a", RValueCaster{}}}; });
110     m.def("cast_rv_nested", []() {
111         std::vector<std::array<std::list<std::unordered_map<std::string, RValueCaster>>, 2>> v;
112         v.emplace_back(); // add an array
113         v.back()[0].emplace_back(); // add a map to the array
114         v.back()[0].back().emplace("b", RValueCaster{});
115         v.back()[0].back().emplace("c", RValueCaster{});
116         v.back()[1].emplace_back(); // add a map to the array
117         v.back()[1].back().emplace("a", RValueCaster{});
118         return v;
119     });
120     static std::array<RValueCaster, 2> lva;
121     static std::unordered_map<std::string, RValueCaster> lvm{{"a", RValueCaster{}}, {"b", RValueCaster{}}};
122     static std::unordered_map<std::string, std::vector<std::list<std::array<RValueCaster, 2>>>> lvn;
123     lvn["a"].emplace_back(); // add a list
124     lvn["a"].back().emplace_back(); // add an array
125     lvn["a"].emplace_back(); // another list
126     lvn["a"].back().emplace_back(); // add an array
127     lvn["b"].emplace_back(); // add a list
128     lvn["b"].back().emplace_back(); // add an array
129     lvn["b"].back().emplace_back(); // add another array
130     m.def("cast_lv_vector", []() -> const decltype(lvv) & { return lvv; });
131     m.def("cast_lv_array", []() -> const decltype(lva) & { return lva; });
132     m.def("cast_lv_map", []() -> const decltype(lvm) & { return lvm; });
133     m.def("cast_lv_nested", []() -> const decltype(lvn) & { return lvn; });
134     // #853:
135     m.def("cast_unique_ptr_vector", []() {
136         std::vector<std::unique_ptr<UserType>> v;
137         v.emplace_back(new UserType{7});
138         v.emplace_back(new UserType{42});
139         return v;
140     });
141 
142     // test_move_out_container
143     struct MoveOutContainer {
144         struct Value { int value; };
145         std::list<Value> move_list() const { return {{0}, {1}, {2}}; }
146     };
147     py::class_<MoveOutContainer::Value>(m, "MoveOutContainerValue")
148         .def_readonly("value", &MoveOutContainer::Value::value);
149     py::class_<MoveOutContainer>(m, "MoveOutContainer")
150         .def(py::init<>())
151         .def_property_readonly("move_list", &MoveOutContainer::move_list);
152 
153     // Class that can be move- and copy-constructed, but not assigned
154     struct NoAssign {
155         int value;
156 
157         explicit NoAssign(int value = 0) : value(value) { }
158         NoAssign(const NoAssign &) = default;
159         NoAssign(NoAssign &&) = default;
160 
161         NoAssign &operator=(const NoAssign &) = delete;
162         NoAssign &operator=(NoAssign &&) = delete;
163     };
164     py::class_<NoAssign>(m, "NoAssign", "Class with no C++ assignment operators")
165         .def(py::init<>())
166         .def(py::init<int>());
167 
168 
169     struct MoveOutDetector
170     {
171         MoveOutDetector() = default;
172         MoveOutDetector(const MoveOutDetector&) = default;
173         MoveOutDetector(MoveOutDetector&& other) noexcept
174          : initialized(other.initialized) {
175             // steal underlying resource
176             other.initialized = false;
177         }
178         bool initialized = true;
179     };
180     py::class_<MoveOutDetector>(m, "MoveOutDetector", "Class with move tracking")
181         .def(py::init<>())
182         .def_readonly("initialized", &MoveOutDetector::initialized);
183 
184 
185 #ifdef PYBIND11_HAS_OPTIONAL
186     // test_optional
187     m.attr("has_optional") = true;
188 
189     using opt_int = std::optional<int>;
190     using opt_no_assign = std::optional<NoAssign>;
191     m.def("double_or_zero", [](const opt_int& x) -> int {
192         return x.value_or(0) * 2;
193     });
194     m.def("half_or_none", [](int x) -> opt_int {
195         return x ? opt_int(x / 2) : opt_int();
196     });
197     m.def("test_nullopt", [](opt_int x) {
198         return x.value_or(42);
199     }, py::arg_v("x", std::nullopt, "None"));
200     m.def("test_no_assign", [](const opt_no_assign &x) {
201         return x ? x->value : 42;
202     }, py::arg_v("x", std::nullopt, "None"));
203 
204     m.def("nodefer_none_optional", [](std::optional<int>) { return true; });
205     m.def("nodefer_none_optional", [](py::none) { return false; });
206 
207     using opt_holder = OptionalHolder<std::optional, MoveOutDetector>;
208     py::class_<opt_holder>(m, "OptionalHolder", "Class with optional member")
209         .def(py::init<>())
210         .def_readonly("member", &opt_holder::member)
211         .def("member_initialized", &opt_holder::member_initialized);
212 #endif
213 
214 #ifdef PYBIND11_HAS_EXP_OPTIONAL
215     // test_exp_optional
216     m.attr("has_exp_optional") = true;
217 
218     using exp_opt_int = std::experimental::optional<int>;
219     using exp_opt_no_assign = std::experimental::optional<NoAssign>;
220     m.def("double_or_zero_exp", [](const exp_opt_int& x) -> int {
221         return x.value_or(0) * 2;
222     });
223     m.def("half_or_none_exp", [](int x) -> exp_opt_int {
224         return x ? exp_opt_int(x / 2) : exp_opt_int();
225     });
226     m.def("test_nullopt_exp", [](exp_opt_int x) {
227         return x.value_or(42);
228     }, py::arg_v("x", std::experimental::nullopt, "None"));
229     m.def("test_no_assign_exp", [](const exp_opt_no_assign &x) {
230         return x ? x->value : 42;
231     }, py::arg_v("x", std::experimental::nullopt, "None"));
232 
233     using opt_exp_holder = OptionalHolder<std::experimental::optional, MoveOutDetector>;
234     py::class_<opt_exp_holder>(m, "OptionalExpHolder", "Class with optional member")
235         .def(py::init<>())
236         .def_readonly("member", &opt_exp_holder::member)
237         .def("member_initialized", &opt_exp_holder::member_initialized);
238 #endif
239 
240 #ifdef PYBIND11_HAS_VARIANT
241     static_assert(std::is_same<py::detail::variant_caster_visitor::result_type, py::handle>::value,
242                   "visitor::result_type is required by boost::variant in C++11 mode");
243 
244     struct visitor {
245         using result_type = const char *;
246 
247         result_type operator()(int) { return "int"; }
248         result_type operator()(std::string) { return "std::string"; }
249         result_type operator()(double) { return "double"; }
250         result_type operator()(std::nullptr_t) { return "std::nullptr_t"; }
251     };
252 
253     // test_variant
254     m.def("load_variant", [](variant<int, std::string, double, std::nullptr_t> v) {
255         return py::detail::visit_helper<variant>::call(visitor(), v);
256     });
257     m.def("load_variant_2pass", [](variant<double, int> v) {
258         return py::detail::visit_helper<variant>::call(visitor(), v);
259     });
260     m.def("cast_variant", []() {
261         using V = variant<int, std::string>;
262         return py::make_tuple(V(5), V("Hello"));
263     });
264 #endif
265 
266     // #528: templated constructor
267     // (no python tests: the test here is that this compiles)
268     m.def("tpl_ctor_vector", [](std::vector<TplCtorClass> &) {});
269     m.def("tpl_ctor_map", [](std::unordered_map<TplCtorClass, TplCtorClass> &) {});
270     m.def("tpl_ctor_set", [](std::unordered_set<TplCtorClass> &) {});
271 #if defined(PYBIND11_HAS_OPTIONAL)
272     m.def("tpl_constr_optional", [](std::optional<TplCtorClass> &) {});
273 #elif defined(PYBIND11_HAS_EXP_OPTIONAL)
274     m.def("tpl_constr_optional", [](std::experimental::optional<TplCtorClass> &) {});
275 #endif
276 
277     // test_vec_of_reference_wrapper
278     // #171: Can't return STL structures containing reference wrapper
279     m.def("return_vec_of_reference_wrapper", [](std::reference_wrapper<UserType> p4) {
280         static UserType p1{1}, p2{2}, p3{3};
281         return std::vector<std::reference_wrapper<UserType>> {
282             std::ref(p1), std::ref(p2), std::ref(p3), p4
283         };
284     });
285 
286     // test_stl_pass_by_pointer
287     m.def("stl_pass_by_pointer", [](std::vector<int>* v) { return *v; }, "v"_a=nullptr);
288 
289     // #1258: pybind11/stl.h converts string to vector<string>
290     m.def("func_with_string_or_vector_string_arg_overload", [](std::vector<std::string>) { return 1; });
291     m.def("func_with_string_or_vector_string_arg_overload", [](std::list<std::string>) { return 2; });
292     m.def("func_with_string_or_vector_string_arg_overload", [](std::string) { return 3; });
293 
294     class Placeholder {
295     public:
296         Placeholder() { print_created(this); }
297         Placeholder(const Placeholder &) = delete;
298         ~Placeholder() { print_destroyed(this); }
299     };
300     py::class_<Placeholder>(m, "Placeholder");
301 
302     /// test_stl_vector_ownership
303     m.def("test_stl_ownership",
304           []() {
305               std::vector<Placeholder *> result;
306               result.push_back(new Placeholder());
307               return result;
308           },
309           py::return_value_policy::take_ownership);
310 
311     m.def("array_cast_sequence", [](std::array<int, 3> x) { return x; });
312 
313     /// test_issue_1561
314     struct Issue1561Inner { std::string data; };
315     struct Issue1561Outer { std::vector<Issue1561Inner> list; };
316 
317     py::class_<Issue1561Inner>(m, "Issue1561Inner")
318         .def(py::init<std::string>())
319         .def_readwrite("data", &Issue1561Inner::data);
320 
321     py::class_<Issue1561Outer>(m, "Issue1561Outer")
322         .def(py::init<>())
323         .def_readwrite("list", &Issue1561Outer::list);
324 }
325