From d4d5eaa6f850273e562e1ba2912971078390bcde Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Tue, 10 Mar 2015 22:52:17 +1100
Subject: [PATCH] traits: add func_traits for return types

---
 types/traits.hpp | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/types/traits.hpp b/types/traits.hpp
index 8a4e77b4..4c47e119 100644
--- a/types/traits.hpp
+++ b/types/traits.hpp
@@ -20,6 +20,7 @@
 #ifndef __UTIL_TYPES_TRAITS_HPP
 #define __UTIL_TYPES_TRAITS_HPP
 
+#include <memory>
 #include <type_traits>
 
 //-----------------------------------------------------------------------------
@@ -70,4 +71,23 @@ template <typename T, typename U> struct is_lossless_cast : std::enable_if<
     std::true_type
 >::value { };
 
+
+//-----------------------------------------------------------------------------
+template <typename T>
+struct func_traits : public func_traits<decltype(&T::operator())>
+{ };
+
+
+template <typename C, typename R, typename ...Args>
+struct func_traits<R(C::*)(Args...) const> {
+    typedef R return_type;
+};
+
+
+template <typename R, typename ...Args>
+struct func_traits<R(Args...)> {
+    typedef R return_type;
+};
+
+
 #endif