std::vector<ObjectA> aArray;
std::vector<ObjectB> bArray;
std::transform(
    aArray.cbegin(),
    aArray.cend(),
    std::back_inserter(bArray),
    [](const auto& aObject) {
        return ObjectB{
            // Try to do autocomplete here:
            aObject.    // autocomplete menu does not show   
        };
    }
);

    [](const ObjectA& aObject) {
        return ObjectB{
            // Try to do autocomplete here:
            aObject.    // autocomplete menu SHOWS!
        };
    }