From 89005dbeb7edebba8ae9724d2e3b21b026e90ac7 Mon Sep 17 00:00:00 2001
From: Ichthyostega <prg@ichthyostega.de>
Date: Sun, 26 Nov 2017 22:29:51 +0100
Subject: [PATCH] TreeExplorer: fix spurious copy of iterator (argument) on
 functor invocation

...since our iterators *always* yield a reference to the exposed element,
we can *always* get that referency into the nested yield to obtain the value
---
 src/lib/iter-tree-explorer.hpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/lib/iter-tree-explorer.hpp b/src/lib/iter-tree-explorer.hpp
index c3af24eea..0493b9792 100644
--- a/src/lib/iter-tree-explorer.hpp
+++ b/src/lib/iter-tree-explorer.hpp
@@ -354,7 +354,7 @@ namespace lib {
         template<class IT>
         struct ArgAccessor<IT,   enable_if<std::is_convertible<typename IT::value_type, Arg>>>
           {
-            static auto build() { return [](auto iter) { return *iter; }; }
+            static auto build() { return [](auto& iter) { return *iter; }; }
           };