From 28a789068185b35f262cfa904d72c136dde54cfa Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Mon, 24 Feb 2020 14:40:36 +1100
Subject: [PATCH] types/tagged: use concepts to restrict assignable types

---
 types/tagged.hpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/types/tagged.hpp b/types/tagged.hpp
index 03b4c590..2a57528d 100644
--- a/types/tagged.hpp
+++ b/types/tagged.hpp
@@ -52,6 +52,7 @@ namespace cruft {
 
         //---------------------------------------------------------------------
         template <typename InitialT>
+        requires (cruft::concepts::same_as<std::remove_cvref_t<InitialT>, ValueT> || ...)
         tagged (InitialT &&initial)
         {
             set<InitialT> (std::forward<InitialT> (initial));