includes/type: Added BCD type

includes/type/bcd.pat

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <std/io.pat>
+
+namespace type {
+
+    struct BCD<auto Digits> {
+        u8 bytes[Digits];
+    } [[sealed, format_read("type::impl::format_bcd")]];
+
+    namespace impl {
+
+        fn format_bcd(ref auto bcd) {
+            str result;
+
+            for (u32 i = 0, i < sizeof(bcd.bytes), i += 1) {
+                u8 byte = bcd.bytes[i];
+                if (byte >= 10)
+                    return "Invalid";
+
+                result += std::format("{}", byte);
+            }
+
+            return result;
+        };
+
+    }
+
+}