test_local_bindings.cpp

/*
    tests/test_local_bindings.cpp -- tests the py::module_local class feature which makes a class
                                     binding local to the module in which it is defined.

    Copyright (c) 2017 Jason Rhinelander <jason@imaginary.ca>

    All rights reserved. Use of this source code is governed by a
    BSD-style license that can be found in the LICENSE file.
*/

#include <pybind11/stl.h>
#include <pybind11/stl_bind.h>

#include "local_bindings.h"
#include "pybind11_tests.h"

#include <numeric>
#include <utility>

TEST_SUBMODULE(local_bindings, m) {
    // test_load_external
    m.def("load_external1", [](ExternalType1 &e) { return e.i; });
    m.def("load_external2", [](ExternalType2 &e) { return e.i; });
    m.def("load_external3", [](ExternalType3 &e) { return e.i; });

    struct SharedKeepAlive {
        std::shared_ptr<int> contents;
        int value() const { return contents ? *contents : -20251012; }
        long use_count() const { return contents.use_count(); }
    };
    py::class_<SharedKeepAlive>(m, "SharedKeepAlive")
        .def_property_readonly("value", &SharedKeepAlive::value)
        .def_property_readonly("use_count", &SharedKeepAlive::use_count);
    m.def("load_external2_shared", [](const std::shared_ptr<ExternalType2> &p) {
        return SharedKeepAlive{std::shared_ptr<int>(p, &p->i)};
    });
    m.def("load_external3_shared", [](const std::shared_ptr<ExternalType3> &p) {
        return SharedKeepAlive{std::shared_ptr<int>(p, &p->i)};
    });
    m.def("load_external1_unique", [](std::unique_ptr<ExternalType1> p) { return p->i; });
    m.def("load_external3_unique", [](std::unique_ptr<ExternalType3> p) { return p->i; });

    // Aspects of set_foreign_holder that are not covered:
    // - loading a foreign instance into a custom holder should fail
    // - we're only covering the case where the local module doesn't know
    //   about the type; the paths where it does (e.g., if both global and
    //   foreign-module-local bindings exist for the same type) should work
    //   the same way (they use the same code so they very likely do)

    // test_local_bindings
    // Register a class with py::module_local:
    bind_local<LocalType, -1>(m, "LocalType", py::module_local()).def("get3", [](LocalType &t) {
        return t.i + 3;
    });

    m.def("local_value", [](LocalType &l) { return l.i; });

    // test_nonlocal_failure
    // The main pybind11 test module is loaded first, so this registration will succeed (the second
    // one, in pybind11_cross_module_tests.cpp, is designed to fail):
    bind_local<NonLocalType, 0>(m, "NonLocalType")
        .def(py::init<int>())
        .def("get", [](LocalType &i) { return i.i; });

    // test_duplicate_local
    // py::module_local declarations should be visible across compilation units that get linked
    // together; this tries to register a duplicate local.  It depends on a definition in
    // test_class.cpp and should raise a runtime error from the duplicate definition attempt.  If
    // test_class isn't available it *also* throws a runtime error (with "test_class not enabled"
    // as value).
    m.def("register_local_external", [m]() {
        auto main = py::module_::import("pybind11_tests");
        if (py::hasattr(main, "class_")) {
            bind_local<LocalExternal, 7>(m, "LocalExternal", py::module_local());
        } else {
            throw std::runtime_error("test_class not enabled");
        }
    });

    // test_stl_bind_local
    // stl_bind.h binders defaults to py::module_local if the types are local or converting:
    py::bind_vector<LocalVec>(m, "LocalVec");
    py::bind_map<LocalMap>(m, "LocalMap");
    // and global if the type (or one of the types, for the map) is global:
    py::bind_vector<NonLocalVec>(m, "NonLocalVec");
    py::bind_map<NonLocalMap>(m, "NonLocalMap");

    // test_stl_bind_global
    // They can, however, be overridden to global using `py::module_local(false)`:
    bind_local<NonLocal2, 10>(m, "NonLocal2");
    py::bind_vector<LocalVec2>(m, "LocalVec2", py::module_local());
    py::bind_map<NonLocalMap2>(m, "NonLocalMap2", py::module_local(false));

    // test_mixed_local_global
    // We try this both with the global type registered first and vice versa (the order shouldn't
    // matter).
    m.def("register_mixed_global", [m]() {
        bind_local<MixedGlobalLocal, 100>(m, "MixedGlobalLocal", py::module_local(false));
    });
    m.def("register_mixed_local", [m]() {
        bind_local<MixedLocalGlobal, 1000>(m, "MixedLocalGlobal", py::module_local());
    });
    m.def("get_mixed_gl", [](int i) { return MixedGlobalLocal(i); });
    m.def("get_mixed_lg", [](int i) { return MixedLocalGlobal(i); });

    // test_internal_locals_differ
    m.def("local_cpp_types_addr",
          []() { return (uintptr_t) &py::detail::get_local_internals().registered_types_cpp; });

    // test_stl_caster_vs_stl_bind
    m.def("load_vector_via_caster",
          [](std::vector<int> v) { return std::accumulate(v.begin(), v.end(), 0); });

    // test_cross_module_calls
    m.def("return_self", [](LocalVec *v) { return v; });
    m.def("return_copy", [](const LocalVec &v) { return LocalVec(v); });

    class Cat : public pets::Pet {
    public:
        explicit Cat(std::string name) : Pet(std::move(name)) {}
    };
    py::class_<pets::Pet>(m, "Pet", py::module_local()).def("get_name", &pets::Pet::name);
    // Binding for local extending class:
    py::class_<Cat, pets::Pet>(m, "Cat").def(py::init<std::string>());
    m.def("pet_name", [](pets::Pet &p) { return p.name(); });

    py::class_<MixGL>(m, "MixGL").def(py::init<int>());
    m.def("get_gl_value", [](MixGL &o) { return o.i + 10; });

    py::class_<MixGL2>(m, "MixGL2").def(py::init<int>());
}