From 6b62fb1fe6c3752eb50fa134b9c145b1e83eb6c3 Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Tue, 21 Feb 2023 18:23:45 -0800
Subject: [PATCH] ircd::util::returns: Eliminate std::function w/ template
 lambda.

---
 include/ircd/util/returns.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/ircd/util/returns.h b/include/ircd/util/returns.h
index e95aa45a8..86294b5bd 100644
--- a/include/ircd/util/returns.h
+++ b/include/ircd/util/returns.h
@@ -37,7 +37,9 @@ struct ircd::util::returns
 		return ret;
 	}
 
-	returns(const std::function<T ()> &func)
+	template<class F>
+	returns(F&& func,
+	        typename std::enable_if<std::is_invocable_r<T, F>::value, int>::type = 0)
 	:ret{func()}
 	{}