From 8955328479189c3f67b04fdb84d182aee23905fc Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Thu, 6 Apr 2017 17:45:50 -0700
Subject: [PATCH] ircd::util: Add basic STL map transformation functors.

---
 include/ircd/util.h | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/include/ircd/util.h b/include/ircd/util.h
index 023a1193c..40622ae40 100644
--- a/include/ircd/util.h
+++ b/include/ircd/util.h
@@ -559,6 +559,29 @@ at(It &&start,
 }
 
 
+//
+// Some functors for STL
+//
+
+template<class container>
+struct keys
+{
+	auto &operator()(typename container::reference v) const
+	{
+		return v.first;
+	}
+};
+
+template<class container>
+struct values
+{
+	auto &operator()(typename container::reference v) const
+	{
+		return v.second;
+	}
+};
+
+
 //
 // Customized std::string_view (experimental TS / C++17)
 //