...

common/adc_traits.h

@@ -50,6 +50,10 @@ template <typename R>
 concept adc_range_of_view_char_range = std::ranges::range<R> && std::ranges::view<std::ranges::range_value_t<R>> &&
                                        std::same_as<std::ranges::range_value_t<std::ranges::range_value_t<R>>, char>;
 
+template <typename R>
+concept adc_range_of_input_char_range =
+    std::ranges::range<R> && traits::adc_input_char_range<std::ranges::range_value_t<R>>;
+
 // deduce returned type of callable
 // template <typename T>
 // using adc_retval_t = std::invoke_result_t<std::remove_cvref_t<T>>;