Add py::module_local() attribute for module-local type bindings
This commit adds a `py::module_local` attribute that lets you confine a
registered type to the module (more technically, the shared object) in
which it is defined, by registering it with:
py::class_<C>(m, "C", py::module_local())
This will allow the same C++ class `C` to be registered in different
modules with independent sets of class definitions. On the Python side,
two such types will be completely distinct; on the C++ side, the C++
type resolves to a different Python type in each module.
This applies `py::module_local` automatically to `stl_bind.h` bindings
when the container value type looks like something global: i.e. when it
is a converting type (for example, when binding a `std::vector<int>`),
or when it is a registered type itself bound with `py::module_local`.
This should help resolve potential future conflicts (e.g. if two
completely unrelated modules both try to bind a `std::vector<int>`.
Users can override the automatic selection by adding a
`py::module_local()` or `py::module_local(false)`.
Note that this does mildly break backwards compatibility: bound stl
containers of basic types like `std::vector<int>` cannot be bound in one
module and returned in a different module. (This can be re-enabled with
`py::module_local(false)` as described above, but with the potential for
eventual load conflicts).
diff --git a/tests/test_local_bindings.cpp b/tests/test_local_bindings.cpp
new file mode 100644
index 0000000..d98840f
--- /dev/null
+++ b/tests/test_local_bindings.cpp
@@ -0,0 +1,62 @@
+/*
+ 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_tests.h"
+#include "local_bindings.h"
+#include <pybind11/stl_bind.h>
+
+TEST_SUBMODULE(local_bindings, m) {
+
+ // 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<std::vector<LocalType>>(m, "LocalVec");
+ py::bind_map<std::unordered_map<std::string, LocalType>>(m, "LocalMap");
+ // and global if the type (or one of the types, for the map) is global:
+ py::bind_vector<std::vector<NonLocalType>>(m, "NonLocalVec");
+ py::bind_map<std::unordered_map<std::string, NonLocalType>>(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<std::vector<NonLocal2>>(m, "LocalVec2", py::module_local());
+ py::bind_map<std::unordered_map<std::string, uint8_t>>(m, "NonLocalMap2", py::module_local(false));
+
+ // test_internal_locals_differ
+ m.def("local_cpp_types_addr", []() { return (uintptr_t) &py::detail::registered_local_types_cpp(); });
+}