nlohmann::basic_json::get_ptr

template<typename PointerType>
requires std::is_pointer<PointerType>::value&&
                   std::is_const<typename std::remove_pointer<PointerType>::type>::value
constexpr
decltype(std::declval<const basic_json_t&>().get_impl_ptr(std::declval<PointerType>()))
get_ptr() const noexcept;