boost::python string-convertible properties
- by Checkers
I have a C++ class, which has the following methods:
class Bar {
...
    const Foo& getFoo() const;
    void setFoo(const Foo&);
};
where class Foo is convertible to std::string (it has an implicit constructor from std::string and an std::string cast operator).
I define a Boost.Python wrapper class, which, among other things, defines a property based on previous two functions:
class_<Bar>("Bar")
    ...
    .add_property(
        "foo",
        make_function(
            &Bar::getFoo,
            return_value_policy<return_by_value>()),
        &Bar::setFoo)
    ...
I also mark the class as convertible to/from std::string.
implicitly_convertible<std::string, Foo>();
implicitly_convertible<Foo, std::string>();
But at runtime I still get a conversion error trying to access this property:
TypeError: No to_python (by-value) converter found for C++ type: Foo
How to achieve the conversion without too much boilerplate of wrapper functions? (I already have all the conversion functions in class Foo, so duplication is undesirable.