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cxx/mcc_traits.h

@@ -0,0 +1,42 @@
+#pragma once
+
+#include <format>
+#include <ranges>
+
+namespace mcc::traits
+{
+
+template <typename R>
+concept mcc_char_view = std::ranges::view<R> && std::same_as<std::ranges::range_value_t<R>, char>;
+
+
+// input range of char/const char
+template <typename R, typename CharT = char>
+concept mcc_input_char_range =
+    std::ranges::input_range<R> && std::is_same_v<std::remove_cv_t<std::ranges::range_value_t<R>>, CharT>;
+
+
+// output range of char/const char
+template <typename R, typename CharT = char>
+concept mcc_output_char_range =
+    std::ranges::output_range<R, CharT> && std::same_as<std::remove_cv_t<std::ranges::range_value_t<R>>, CharT>;
+
+
+template <typename R>
+concept mcc_view_or_output_char_range = mcc_char_view<R> || mcc_output_char_range<R>;
+
+
+template <typename R>
+concept mcc_range_of_input_char_range =
+    std::ranges::range<R> && traits::mcc_input_char_range<std::ranges::range_value_t<R>>;
+
+
+
+// https://stackoverflow.com/questions/72430369/how-to-check-that-a-type-is-formattable-using-type-traits-concepts)
+template <typename T>
+concept mcc_formattable =
+    requires(T v, std::format_context ctx) { std::formatter<std::remove_cvref_t<T>>().format(v, ctx); };
+
+
+
+}  // namespace mcc::traits