Function cpp_std::add_char16_t_u16_string

pub unsafe fn add_char16_t_u16_string(
    lhs: impl CastInto<Ptr<char16_t>>, 
    rhs: impl CastInto<Ref<U16String>>
) -> CppBox<U16String>

Calls C++ function: std::basic_string<char16_t, std::char_traits<char16_t>, std::allocator<char16_t>> std::operator+(const char16_t* __lhs, const std::basic_string<char16_t, std::char_traits<char16_t>, std::allocator<char16_t>>& __rhs).