Detailed Description

template<typename T>
struct lass::python::PyExportTraitsMaybeNone< T >

Helper class to create PyExportTraits for MaybeNone wrapped types.

MaybeNone does not provide any runtime or compile-time checks. It only serves to alter the type-hint to T | MaybeNone in Python, which is useful for type-checking, see The Any Trick.

MaybeNone<T> types can only be returned from C++ to Python, it doesn't make sense to pass them as function parameters to C++.

Use this helper to create PyExportTraits for your own MaybeNone wrapped types by inheriting from it.

template <typename T, template <typename, typename> class S, typename C>
struct PyExportTraits< MaybeNone< util::SharedPtr<T, S, C> > >: public PyExportTraitsMaybeNone< util::SharedPtr<T, S, C> >
{
    constexpr static const char* py_typing = "T | MaybeNone"; // optional
};

Built-in specializations are provided for raw pointers T*, util::SharedPtr<T>, std::shared_ptr<T>, and std::optional<T>.

Note: If you use typename T as the main template parameter for your actual type, then the Python type will automatically be deduced. If not, or if you still see a T | None type-hint, you can can override the py_typing member to specify the type-hint you want.

See also: MaybeNone; PyExportTraits<MaybeNone<T*>>; PyExportTraits<MaybeNone<util::SharedPtr<T,S,C>>>; PyExportTraits<MaybeNone<std::shared_ptr<T>>>; PyExportTraits<MaybeNone<std::optional<T>>>

Definition at line 695 of file export_traits.h.

The documentation for this struct was generated from the following file:

export_traits.h