Fix unnecessary copies in auto iter (fixes #426)

Also switch to colon-style iteration in some cases. Thanks to Dean
Scarff for drawing this to my attention after detecting some
unnecessary copies with
https://clang.llvm.org/extra/clang-tidy/checks/performance-for-range-copy.html

1 files changed, 3 insertions, 4 deletions

diff --git a/qpdf/fix-qdf.cc b/qpdf/fix-qdf.cc
index 2516a0bd..c50f7b5a 100644
--- a/qpdf/fix-qdf.cc
+++ b/qpdf/fix-qdf.cc
@@ -387,13 +387,12 @@ QdfFixer::writeOstream()
     auto onum = ostream_id;
     std::string offsets;
     auto n = ostream_offsets.size();
-    for (auto iter = ostream_offsets.begin();
-         iter != ostream_offsets.end(); ++iter)
+    for (auto iter: ostream_offsets)
     {
-	(*iter) -= QIntC::to_offset(first);
+	iter -= QIntC::to_offset(first);
 	++onum;
 	offsets += QUtil::int_to_string(onum) + " " +
-            QUtil::int_to_string(*iter) + "\n";
+            QUtil::int_to_string(iter) + "\n";
     }
     auto offset_adjust = QIntC::to_offset(offsets.size());
     first += offset_adjust;