trying to get a c++ object to be used as a python object...

Author: aoloe

eval-set-object/CMakeLists.txt

@@ -0,0 +1,10 @@
+cmake_minimum_required(VERSION 3.4)
+project(scripting)
+
+set(PYBIND11_PYTHON_VERSION 3.4)
+
+FIND_PACKAGE(pybind11 CONFIG)
+
+ADD_EXECUTABLE(scripting src/main.cpp)
+TARGET_LINK_LIBRARIES(scripting ${PYTHON_LIBRARIES})
+TARGET_LINK_LIBRARIES(scripting pybind11::embed)

eval-set-object/README.md

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+# A python script running a PyQt5 input dialog and setting a c++ variable with the value
+
+~~~.sh
+$ mkdir build
+$ cmake -Dpybind11_DIR=/home/ale/bin/pybind11/share/cmake/pybind11 ..
+$ make
+$ ./scripting
+~~~

eval-set-object/src/main.cpp

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+#include <iostream>
+#include <pybind11/pybind11.h>
+#include <pybind11/embed.h>
+
+namespace py = pybind11;
+
+// for the _a string litteral
+// http://pybind11.readthedocs.io/en/stable/basics.html#keyword-arguments
+using namespace pybind11::literals;
+
+struct Foo { int bar = 1; };
+
+
+PYBIND11_EMBEDDED_MODULE(foo_module, m) {
+	py::class_<Foo>(m, "Foo").def_readwrite("bar", &Foo::bar);
+}
+
+int main()
+{
+	py::scoped_interpreter guard{}; // start the interpreter and keep it alive
+
+	Foo foo1, foo2;
+
+	auto module = py::module::import("foo_module");
+
+	auto locals = py::dict("foo_copy"_a=foo1, "foo_ref"_a=&foo2, **module.attr("__dict__"));  // note the &
+	py::exec(R"(
+		print(foo_copy.bar);
+		foo_copy.bar = 5;
+		print(foo_copy.bar);
+		foo_ref.bar = 5;
+	)", py::globals(), locals);
+
+	assert(foo1.bar == 1);
+	assert(foo2.bar == 5);
+
+}