Method pyobject_caster

include/pybind11/cast.h:1530–1530

struct pyobject_caster {
    template <typename T = type, enable_if_t<std::is_same<T, handle>::value, int> = 0>
    pyobject_caster() : value() {}

    // `type` may not be default constructible (e.g. frozenset, anyset).  Initializing `value`
    // to a nil handle is safe since it will only be accessed if `load` succeeds.