From 76b012a5e13d10d3184ca9b5a8e1890c57e3344e Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Sun, 13 Jun 2021 01:42:31 +0100
Subject: Add a concept to differentiate streams better

---
 lib/compileTimeFormatter.h | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/lib/compileTimeFormatter.h b/lib/compileTimeFormatter.h
index 09aae53..3779454 100644
--- a/lib/compileTimeFormatter.h
+++ b/lib/compileTimeFormatter.h
@@ -251,7 +251,12 @@ namespace MyGrate {
 		return FormatterDetail<Str, Str.size()>::get(pn...);
 	}
 
-	template<const Support::basic_fixed_string Str, typename stream, typename... Pn>
+	template<typename T>
+	concept Writable = requires(T s)
+	{
+		{s << 0};
+	};
+	template<const Support::basic_fixed_string Str, Writable stream, typename... Pn>
 	inline auto &
 	scprintf(stream & strm, const Pn &... pn)
 	{
-- 
cgit v1.2.3