From 32f2d6ed9a4d3c2802dafd6fcf62dfaabf97456a Mon Sep 17 00:00:00 2001
From: Ichthyostega <prg@ichthyostega.de>
Date: Sat, 12 Aug 2017 16:27:30 +0200
Subject: [PATCH] IterSource: optimise hand-over at construction

by moving, we can avoid the generation of up to 3 additional shared copies
of the DataHandle. The whole invocation now works without touching any shared count
and thus without incurring a memory barrier...
---
 src/lib/iter-source.hpp | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/lib/iter-source.hpp b/src/lib/iter-source.hpp
index bacc0835e..28d02d29e 100644
--- a/src/lib/iter-source.hpp
+++ b/src/lib/iter-source.hpp
@@ -155,8 +155,8 @@ namespace lib {
       static iterator
       build (IterSource& sourceImpl)
         {
-          DataHandle sourceHandle (&sourceImpl, &detach_without_destroy);
-          return startIteration(sourceHandle);
+          return std::move(
+              startIteration (DataHandle{&sourceImpl, &detach_without_destroy}));
         }
       
       /** build an iterator frontend, thereby managing
@@ -168,8 +168,8 @@ namespace lib {
       static iterator
       build (IterSource* sourceImplObject)
         {
-          DataHandle sourceHandle (sourceImplObject, &destroy_managed_source);
-          return startIteration(sourceHandle);
+          return std::move(
+              startIteration (DataHandle{sourceImplObject, &destroy_managed_source}));
         }
       
       static iterator EMPTY_SOURCE;
@@ -182,7 +182,7 @@ namespace lib {
         {
           REQUIRE (sourceHandle);
           Pos first = sourceHandle->firstResult();
-          return iterator (sourceHandle, first);
+          return {move(sourceHandle), first};
         }