Code clean up: use range-style for loops wherever possible

Remove variables obsoleted by commit 4f24617.

Code clean up: use range-style for loops wherever possible
Remove variables obsoleted by commit 4f24617.
m-holger · Jay Berkenbilt
1 parent 70ccd807
Showing 20 changed files with 72 additions and 166 deletions
examples/pdf-filter-tokens.cc
examples/pdf-invert-images.cc
examples/pdf-overlay-page.cc
examples/pdf-set-form-values.cc
fuzz/qpdf_fuzzer.cc
libqpdf/QPDF.cc
libqpdf/QPDFAcroFormDocumentHelper.cc
libqpdf/QPDFJob.cc
libqpdf/QPDFObjectHandle.cc
libqpdf/QPDFPageDocumentHelper.cc
libqpdf/QPDFTokenizer.cc
libqpdf/QPDFWriter.cc
libqpdf/QPDF_linearization.cc
libqpdf/QPDF_optimization.cc
qpdf/test_driver.cc
qpdf/test_parsedoffset.cc
qpdf/test_pdf_doc_encoding.cc
qpdf/test_pdf_unicode.cc
qpdf/test_tokenizer.cc
qpdf/test_xref.cc
@@ -191,9 +191,7 @@ main(int argc, char* argv[])
     try {
         QPDF pdf;
         pdf.processFile(infilename);
-        std::vector<QPDFPageObjectHelper> pages =
-            QPDFPageDocumentHelper(pdf).getAllPages();
-        for (auto& page: pages) {
+        for (auto& page: QPDFPageDocumentHelper(pdf).getAllPages()) {
             // Attach two token filters to each page of this file.
             // When the file is written, or when the pages' contents
             // are retrieved in any other way, the filters will be
@@ -129,12 +129,9 @@ main(int argc, char* argv[])
         auto p = std::shared_ptr<QPDFObjectHandle::StreamDataProvider>(inv);
         // For each page...
-        std::vector<QPDFPageObjectHelper> pages =
-            QPDFPageDocumentHelper(qpdf).getAllPages();
-        for (auto& page: pages) {
+        for (auto& page: QPDFPageDocumentHelper(qpdf).getAllPages()) {
             // Get all images on the page.
-            std::map<std::string, QPDFObjectHandle> images = page.getImages();
-            for (auto& iter: images) {
+            for (auto& iter: page.getImages()) {
                 QPDFObjectHandle& image = iter.second;
                 QPDFObjectHandle image_dict = image.getDict();
                 QPDFObjectHandle color_space = image_dict.getKey("/ColorSpace");
@@ -40,9 +40,7 @@ stamp_page(char const* infile, char const* stampfile, char const* outfile)
     QPDFObjectHandle stamp_fo = inpdf.copyForeignObject(foreign_fo);
     // For each page...
-    std::vector<QPDFPageObjectHelper> pages =
-        QPDFPageDocumentHelper(inpdf).getAllPages();
-    for (auto& ph: pages) {
+    for (auto& ph: QPDFPageDocumentHelper(inpdf).getAllPages()) {
         // Find a unique resource name for the new form XObject
         QPDFObjectHandle resources = ph.getAttribute("/Resources", true);
         int min_suffix = 1;
@@ -50,15 +50,11 @@ main(int argc, char* argv[])
         // illustrates how we can map from annotations to fields.
         QPDFAcroFormDocumentHelper afdh(qpdf);
-        QPDFPageDocumentHelper pdh(qpdf);
-        std::vector<QPDFPageObjectHelper> pages = pdh.getAllPages();
-        for (auto const& page: pages) {
+        for (auto const& page: QPDFPageDocumentHelper(qpdf).getAllPages()) {
             // Get all widget annotations for each page. Widget
             // annotations are the ones that contain the details of
             // what's in a form field.
-            std::vector<QPDFAnnotationObjectHelper> annotations =
-                afdh.getWidgetAnnotationsForPage(page);
-            for (auto& annot: annotations) {
+            for (auto& annot: afdh.getWidgetAnnotationsForPage(page)) {
                 // For each annotation, find its associated field. If
                 // it's a text field, set its value.
                 QPDFFormFieldObjectHelper ffh =
@@ -131,10 +131,9 @@ FuzzHelper::testPages()
     QPDFAcroFormDocumentHelper afdh(*q);
     afdh.generateAppearancesIfNeeded();
     pdh.flattenAnnotations();
-    std::vector<QPDFPageObjectHelper> pages = pdh.getAllPages();
     DiscardContents discard_contents;
     int pageno = 0;
-    for (auto& page: pages) {
+    for (auto& page: pdh.getAllPages()) {
         ++pageno;
         try {
             page.coalesceContentStreams();
@@ -145,9 +144,7 @@ FuzzHelper::testPages()
             page_obj.getJSON(JSON::LATEST, true).unparse();
             odh.getOutlinesForPage(page_obj.getObjGen());
-            std::vector<QPDFAnnotationObjectHelper> annotations =
-                afdh.getWidgetAnnotationsForPage(page);
-            for (auto& aoh: annotations) {
+            for (auto& aoh: afdh.getWidgetAnnotationsForPage(page)) {
                 afdh.getFieldForAnnotation(aoh);
             }
         } catch (QPDFExc& e) {
@@ -164,8 +161,7 @@ FuzzHelper::testOutlines()
     QPDFOutlineDocumentHelper odh(*q);
     queue.push_back(odh.getTopLevelOutlines());
     while (!queue.empty()) {
-        std::vector<QPDFOutlineObjectHelper>& outlines = *(queue.begin());
-        for (auto& ol: outlines) {
+        for (auto& ol: *(queue.begin())) {
             ol.getDestPage();
             queue.push_back(ol.getKids());
         }
@@ -2369,8 +2369,7 @@ QPDF::reserveObjects(QPDFObjectHandle foreign, ObjCopier&amp; obj_copier, bool top)
         }
     } else if (foreign.isDictionary()) {
         QTC::TC("qpdf", "QPDF reserve dictionary");
-        std::set<std::string> keys = foreign.getKeys();
-        for (auto const& key: keys) {
+        for (auto const& key: foreign.getKeys()) {
             reserveObjects(foreign.getKey(key), obj_copier, false);
         }
     } else if (foreign.isStream()) {
@@ -294,12 +294,8 @@ QPDFAcroFormDocumentHelper::analyze()
     // a file that contains this kind of error will probably not
     // actually work with most viewers.
-    QPDFPageDocumentHelper dh(this->qpdf);
-    std::vector<QPDFPageObjectHelper> pages = dh.getAllPages();
-    for (auto const& ph: pages) {
-        std::vector<QPDFAnnotationObjectHelper> annots =
-            getWidgetAnnotationsForPage(ph);
-        for (auto const& iter: annots) {
+    for (auto const& ph: QPDFPageDocumentHelper(this->qpdf).getAllPages()) {
+        for (auto const& iter: getWidgetAnnotationsForPage(ph)) {
             QPDFObjectHandle annot(iter.getObjectHandle());
             QPDFObjGen og(annot.getObjGen());
             if (this->m->annotation_to_field.count(og) == 0) {
@@ -451,12 +447,8 @@ QPDFAcroFormDocumentHelper::generateAppearancesIfNeeded()
         return;
     }
-    QPDFPageDocumentHelper pdh(this->qpdf);
-    std::vector<QPDFPageObjectHelper> pages = pdh.getAllPages();
-    for (auto const& page: pages) {
-        std::vector<QPDFAnnotationObjectHelper> annotations =
-            getWidgetAnnotationsForPage(page);
-        for (auto& aoh: annotations) {
+    for (auto const& page: QPDFPageDocumentHelper(this->qpdf).getAllPages()) {
+        for (auto& aoh: getWidgetAnnotationsForPage(page)) {
             QPDFFormFieldObjectHelper ffh = getFieldForAnnotation(aoh);
             if (ffh.getFieldType() == "/Btn") {
                 // Rather than generating appearances for button
@@ -867,11 +867,9 @@ QPDFJob::doCheck(QPDF&amp; pdf)
         w.write();
         // Parse all content streams
-        QPDFPageDocumentHelper dh(pdf);
-        std::vector<QPDFPageObjectHelper> pages = dh.getAllPages();
         DiscardContents discard_contents;
         int pageno = 0;
-        for (auto& page: pages) {
+        for (auto& page: QPDFPageDocumentHelper(pdf).getAllPages()) {
             ++pageno;
             try {
                 page.parseContents(&discard_contents);
@@ -939,11 +937,9 @@ QPDFJob::doShowObj(QPDF&amp; pdf)
 void
 QPDFJob::doShowPages(QPDF& pdf)
 {
-    QPDFPageDocumentHelper dh(pdf);
-    std::vector<QPDFPageObjectHelper> pages = dh.getAllPages();
     int pageno = 0;
     auto& cout = *this->m->cout;
-    for (auto& ph: pages) {
+    for (auto& ph: QPDFPageDocumentHelper(pdf).getAllPages()) {
         QPDFObjectHandle page = ph.getObjectHandle();
         ++pageno;
@@ -966,8 +962,7 @@ QPDFJob::doShowPages(QPDF&amp; pdf)
         }
         cout << "  content:" << std::endl;
-        std::vector<QPDFObjectHandle> content = ph.getPageContents();
-        for (auto& iter2: content) {
+        for (auto& iter2: ph.getPageContents()) {
             cout << "    " << iter2.unparse() << std::endl;
         }
     }
@@ -1085,8 +1080,7 @@ QPDFJob::doJSONObjects(Pipeline* p, bool&amp; first, QPDF&amp; pdf)
     JSON::writeDictionaryOpen(p, first_object, 1);
     bool all_objects = m->json_objects.empty();
     std::set<QPDFObjGen> wanted_og = getWantedJSONObjects();
-    std::vector<QPDFObjectHandle> objects = pdf.getAllObjects();
-    for (auto& obj: objects) {
+    for (auto& obj: pdf.getAllObjects()) {
         std::string key = obj.unparse();
         if (this->m->json_version > 1) {
             key = "obj:" + key;
@@ -1140,20 +1134,17 @@ QPDFJob::doJSONPages(Pipeline* p, bool&amp; first, QPDF&amp; pdf)
     JSON::writeDictionaryKey(p, first, "pages", 0);
     bool first_page = true;
     JSON::writeArrayOpen(p, first_page, 1);
-    QPDFPageDocumentHelper pdh(pdf);
     QPDFPageLabelDocumentHelper pldh(pdf);
     QPDFOutlineDocumentHelper odh(pdf);
-    std::vector<QPDFPageObjectHelper> pages = pdh.getAllPages();
     int pageno = -1;
-    for (auto& ph: pages) {
+    for (auto& ph: QPDFPageDocumentHelper(pdf).getAllPages()) {
         ++pageno;
         JSON j_page = JSON::makeDictionary();
         QPDFObjectHandle page = ph.getObjectHandle();
         j_page.addDictionaryMember(
             "object", page.getJSON(this->m->json_version));
         JSON j_images = j_page.addDictionaryMember("images", JSON::makeArray());
-        std::map<std::string, QPDFObjectHandle> images = ph.getImages();
-        for (auto const& iter2: images) {
+        for (auto const& iter2: ph.getImages()) {
             JSON j_image = j_images.addArrayElement(JSON::makeDictionary());
             j_image.addDictionaryMember("name", JSON::makeString(iter2.first));
             QPDFObjectHandle image = iter2.second;
@@ -1195,8 +1186,7 @@ QPDFJob::doJSONPages(Pipeline* p, bool&amp; first, QPDF&amp; pdf)
         j_page.addDictionaryMember("images", j_images);
         JSON j_contents =
             j_page.addDictionaryMember("contents", JSON::makeArray());
-        std::vector<QPDFObjectHandle> content = ph.getPageContents();
-        for (auto& iter2: content) {
+        for (auto& iter2: ph.getPageContents()) {
             j_contents.addArrayElement(iter2.getJSON(this->m->json_version));
         }
         j_page.addDictionaryMember(
@@ -1285,10 +1275,8 @@ void
 QPDFJob::doJSONOutlines(Pipeline* p, bool& first, QPDF& pdf)
 {
     std::map<QPDFObjGen, int> page_numbers;
-    QPDFPageDocumentHelper dh(pdf);
-    std::vector<QPDFPageObjectHelper> pages = dh.getAllPages();
     int n = 0;
-    for (auto const& ph: pages) {
+    for (auto const& ph: QPDFPageDocumentHelper(pdf).getAllPages()) {
         QPDFObjectHandle oh = ph.getObjectHandle();
         page_numbers[oh.getObjGen()] = ++n;
     }
@@ -1309,14 +1297,10 @@ QPDFJob::doJSONAcroform(Pipeline* p, bool&amp; first, QPDF&amp; pdf)
     j_acroform.addDictionaryMember(
         "needappearances", JSON::makeBool(afdh.getNeedAppearances()));
     JSON j_fields = j_acroform.addDictionaryMember("fields", JSON::makeArray());
-    QPDFPageDocumentHelper pdh(pdf);
-    std::vector<QPDFPageObjectHelper> pages = pdh.getAllPages();
     int pagepos1 = 0;
-    for (auto const& page: pages) {
+    for (auto const& page: QPDFPageDocumentHelper(pdf).getAllPages()) {
         ++pagepos1;
-        std::vector<QPDFAnnotationObjectHelper> annotations =
-            afdh.getWidgetAnnotationsForPage(page);
-        for (auto& aoh: annotations) {
+        for (auto& aoh: afdh.getWidgetAnnotationsForPage(page)) {
             QPDFFormFieldObjectHelper ffh = afdh.getFieldForAnnotation(aoh);
             JSON j_field = j_fields.addArrayElement(JSON::makeDictionary());
             j_field.addDictionaryMember(
@@ -1355,8 +1339,7 @@ QPDFJob::doJSONAcroform(Pipeline* p, bool&amp; first, QPDF&amp; pdf)
             j_field.addDictionaryMember("istext", JSON::makeBool(ffh.isText()));
             JSON j_choices =
                 j_field.addDictionaryMember("choices", JSON::makeArray());
-            std::vector<std::string> choices = ffh.getChoices();
-            for (auto const& choice: choices) {
+            for (auto const& choice: ffh.getChoices()) {
                 j_choices.addArrayElement(JSON::makeString(choice));
             }
             JSON j_annot = j_field.addDictionaryMember(
@@ -2282,19 +2265,16 @@ QPDFJob::handleTransformations(QPDF&amp; pdf)
     };
     if (m->externalize_inline_images ||
         (m->optimize_images && (!m->keep_inline_images))) {
-        std::vector<QPDFPageObjectHelper> pages = dh.getAllPages();
-        for (auto& ph: pages) {
+        for (auto& ph: dh.getAllPages()) {
             ph.externalizeInlineImages(m->ii_min_bytes);
         }
     }
     if (m->optimize_images) {
         int pageno = 0;
-        std::vector<QPDFPageObjectHelper> pages = dh.getAllPages();
-        for (auto& ph: pages) {
+        for (auto& ph: dh.getAllPages()) {
             ++pageno;
             QPDFObjectHandle page = ph.getObjectHandle();
-            std::map<std::string, QPDFObjectHandle> images = ph.getImages();
-            for (auto& iter2: images) {
+            for (auto& iter2: ph.getImages()) {
                 std::string name = iter2.first;
                 QPDFObjectHandle& image = iter2.second;
                 ImageOptimizer* io = new ImageOptimizer(
@@ -2330,8 +2310,7 @@ QPDFJob::handleTransformations(QPDF&amp; pdf)
             m->flatten_annotations_required, m->flatten_annotations_forbidden);
     }
     if (m->coalesce_contents) {
-        std::vector<QPDFPageObjectHelper> pages = dh.getAllPages();
-        for (auto& page: pages) {
+        for (auto& page: dh.getAllPages()) {
             page.coalesceContentStreams();
         }
     }
@@ -2805,9 +2784,7 @@ QPDFJob::handleRotations(QPDF&amp; pdf)
         std::string const& range = iter.first;
         QPDFJob::RotationSpec const& rspec = iter.second;
         // range has been previously validated
-        std::vector<int> to_rotate =
-            QUtil::parse_numrange(range.c_str(), npages);
-        for (int pageno_iter: to_rotate) {
+        for (int pageno_iter: QUtil::parse_numrange(range.c_str(), npages)) {
             int pageno = pageno_iter - 1;
             if ((pageno >= 0) && (pageno < npages)) {
                 pages.at(QIntC::to_size(pageno))
@@ -1240,12 +1240,10 @@ QPDFObjectHandle::getResourceNames()
     if (!isDictionary()) {
         return result;
     }
-    std::set<std::string> keys = getKeys();
-    for (auto const& key: keys) {
+    for (auto const& key: getKeys()) {
         QPDFObjectHandle val = getKey(key);
         if (val.isDictionary()) {
-            std::set<std::string> val_keys = val.getKeys();
-            for (auto const& val_key: val_keys) {
+            for (auto const& val_key: val.getKeys()) {
                 result.insert(val_key);
             }
         }
@@ -1642,14 +1640,12 @@ QPDFObjectHandle::addPageContents(QPDFObjectHandle new_contents, bool first)
 {
     new_contents.assertStream();
-    std::vector<QPDFObjectHandle> orig_contents = getPageContents();
-
     std::vector<QPDFObjectHandle> content_streams;
     if (first) {
         QTC::TC("qpdf", "QPDFObjectHandle prepend page contents");
         content_streams.push_back(new_contents);
     }
-    for (auto const& iter: orig_contents) {
+    for (auto const& iter: getPageContents()) {
         QTC::TC("qpdf", "QPDFObjectHandle append page contents");
         content_streams.push_back(iter);
     }
@@ -1657,8 +1653,7 @@ QPDFObjectHandle::addPageContents(QPDFObjectHandle new_contents, bool first)
         content_streams.push_back(new_contents);
     }
-    QPDFObjectHandle contents = QPDFObjectHandle::newArray(content_streams);
-    this->replaceKey("/Contents", contents);
+    this->replaceKey("/Contents", newArray(content_streams));
 }
 void
@@ -2927,9 +2922,8 @@ QPDFObjectHandle::copyObject(
         new_obj = std::shared_ptr<QPDFObject>(new QPDF_Array(items));
     } else if (isDictionary()) {
         QTC::TC("qpdf", "QPDFObjectHandle clone dictionary");
-        std::set<std::string> keys = getKeys();
         std::map<std::string, QPDFObjectHandle> items;
-        for (auto const& key: keys) {
+        for (auto const& key: getKeys()) {
             items[key] = getKey(key);
             if ((!first_level_only) &&
                 (cross_indirect || (!items[key].isIndirect()))) {
@@ -12,9 +12,8 @@ QPDFPageDocumentHelper::QPDFPageDocumentHelper(QPDF&amp; qpdf) :
 std::vector<QPDFPageObjectHelper>
 QPDFPageDocumentHelper::getAllPages()
 {
-    std::vector<QPDFObjectHandle> const& pages_v = this->qpdf.getAllPages();
     std::vector<QPDFPageObjectHelper> pages;
-    for (auto const& iter: pages_v) {
+    for (auto const& iter: this->qpdf.getAllPages()) {
         pages.push_back(QPDFPageObjectHelper(iter));
     }
     return pages;
@@ -29,8 +28,7 @@ QPDFPageDocumentHelper::pushInheritedAttributesToPage()
 void
 QPDFPageDocumentHelper::removeUnreferencedResources()
 {
-    std::vector<QPDFPageObjectHelper> pages = getAllPages();
-    for (auto& ph: pages) {
+    for (auto& ph: getAllPages()) {
         ph.removeUnreferencedResources();
     }
 }
@@ -66,8 +64,7 @@ QPDFPageDocumentHelper::flattenAnnotations(
             .warnIfPossible("document does not have updated appearance streams,"
                             " so form fields will not be flattened");
     }
-    std::vector<QPDFPageObjectHelper> pages = getAllPages();
-    for (auto& ph: pages) {
+    for (auto& ph: getAllPages()) {
         QPDFObjectHandle resources = ph.getAttribute("/Resources", true);
         if (!resources.isDictionary()) {
             // This should never happen and is not exercised in the
@@ -567,8 +567,7 @@ QPDFTokenizer::findEI(std::shared_ptr&lt;InputSource&gt; input)
                 bool found_alpha = false;
                 bool found_non_printable = false;
                 bool found_other = false;
-                std::string value = t.getValue();
-                for (char ch: value) {
+                for (char ch: t.getValue()) {
                     if (((ch >= 'a') && (ch <= 'z')) ||
                         ((ch >= 'A') && (ch <= 'Z')) || (ch == '*')) {
                         // Treat '*' as alpha since there are valid
@@ -1237,8 +1237,7 @@ QPDFWriter::enqueueObject(QPDFObjectHandle object)
             }
         }
     } else if (object.isDictionary()) {
-        std::set<std::string> keys = object.getKeys();
-        for (auto const& key: keys) {
+        for (auto const& key: object.getKeys()) {
             if (!this->m->linearized) {
                 enqueueObject(object.getKey(key));
             }
@@ -1283,8 +1282,7 @@ QPDFWriter::writeTrailer(
         writeString(" /Size ");
         writeString(QUtil::int_to_string(size));
     } else {
-        std::set<std::string> keys = trailer.getKeys();
-        for (auto const& key: keys) {
+        for (auto const& key: trailer.getKeys()) {
             writeStringQDF("  ");
             writeStringNoQDF(" ");
             writeString(QPDF_Name::normalizeName(key));
@@ -1644,8 +1642,7 @@ QPDFWriter::unparseObject(
         writeString("<<");
         writeStringQDF("\n");
-        std::set<std::string> keys = object.getKeys();
-        for (auto const& key: keys) {
+        for (auto const& key: object.getKeys()) {
             writeStringQDF(indent);
             writeStringQDF("  ");
             writeStringNoQDF(" ");
@@ -2074,8 +2071,7 @@ QPDFWriter::generateID()
         seed += " QPDF ";
         if (trailer.hasKey("/Info")) {
             QPDFObjectHandle info = trailer.getKey("/Info");
-            std::set<std::string> keys = info.getKeys();
-            for (auto const& key: keys) {
+            for (auto const& key: info.getKeys()) {
                 QPDFObjectHandle obj = info.getKey(key);
                 if (obj.isString()) {
                     seed += " ";
@@ -2365,8 +2361,7 @@ QPDFWriter::doWriteSetup()
     if (this->m->linearized) {
         // Page dictionaries are not allowed to be compressed objects.
-        std::vector<QPDFObjectHandle> pages = this->m->pdf.getAllPages();
-        for (auto& page: pages) {
+        for (auto& page: this->m->pdf.getAllPages()) {
             QPDFObjGen og = page.getObjGen();
             if (this->m->object_to_object_stream.count(og)) {
                 QTC::TC("qpdf", "QPDFWriter uncompressing page dictionary");
@@ -3251,8 +3246,7 @@ QPDFWriter::enqueueObjectsStandard()
     // dictionary into the queue, handling direct objects recursively.
     // Root is already there, so enqueuing it a second time is a
     // no-op.
-    std::set<std::string> keys = trailer.getKeys();
-    for (auto const& key: keys) {
+    for (auto const& key: trailer.getKeys()) {
         enqueueObject(trailer.getKey(key));
     }
 }
@@ -3276,8 +3270,7 @@ QPDFWriter::enqueueObjectsPCLm()
         // enqueue all the strips for each page
         QPDFObjectHandle strips = page.getKey("/Resources").getKey("/XObject");
-        std::set<std::string> keys = strips.getKeys();
-        for (auto const& image: keys) {
+        for (auto const& image: strips.getKeys()) {
             enqueueObject(strips.getKey(image));
             enqueueObject(QPDFObjectHandle::newStream(
                 &this->m->pdf, image_transform_content));
@@ -663,9 +663,8 @@ QPDF::maxEnd(ObjUser const&amp; ou)
     if (this->m->obj_user_to_objects.count(ou) == 0) {
         stopOnError("no entry in object user table for requested object user");
     }
-    std::set<QPDFObjGen> const& ogs = this->m->obj_user_to_objects[ou];
     qpdf_offset_t end = 0;
-    for (auto const& og: ogs) {
+    for (auto const& og: this->m->obj_user_to_objects[ou]) {
         if (this->m->obj_cache.count(og) == 0) {
             stopOnError("unknown object referenced in object user table");
         }
@@ -1474,8 +1473,7 @@ QPDF::calculateLinearizationData(std::map&lt;int, int&gt; const&amp; object_stream_data)
             stopOnError("found unreferenced page while"
                         " calculating linearization data");
         }
-        std::set<QPDFObjGen> ogs = this->m->obj_user_to_objects[ou];
-        for (auto const& og: ogs) {
+        for (auto const& og: this->m->obj_user_to_objects[ou]) {
             if (lc_other_page_private.count(og)) {
                 lc_other_page_private.erase(og);
                 this->m->part7.push_back(objGenToIndirect(og));
@@ -1637,8 +1635,7 @@ QPDF::calculateLinearizationData(std::map&lt;int, int&gt; const&amp; object_stream_data)
             stopOnError("found unreferenced page while"
                         " calculating linearization data");
         }
-        std::set<QPDFObjGen> const& ogs = this->m->obj_user_to_objects[ou];
-        for (auto const& og: ogs) {
+        for (auto const& og: this->m->obj_user_to_objects[ou]) {
             if ((this->m->object_to_obj_users[og].size() > 1) &&
                 (obj_to_index.count(og.getObj()) > 0)) {
                 int idx = obj_to_index[og.getObj()];
@@ -90,8 +90,7 @@ QPDF::optimize(
     }
     // Traverse document-level items
-    std::set<std::string> keys = this->m->trailer.getKeys();
-    for (auto const& key: keys) {
+    for (auto const& key: this->m->trailer.getKeys()) {
         if (key == "/Root") {
             // handled separately
         } else {
@@ -102,8 +101,7 @@ QPDF::optimize(
         }
     }
-    keys = root.getKeys();
-    for (auto const& key: keys) {
+    for (auto const& key: root.getKeys()) {
         // Technically, /I keys from /Thread dictionaries are supposed
         // to be handled separately, but we are going to disregard
         // that specification for now.  There is loads of evidence
@@ -205,8 +203,7 @@ QPDF::pushInheritedAttributesToPageInternal(
         // that have values for this attribute.
         std::set<std::string> inheritable_keys;
-        std::set<std::string> keys = cur_pages.getKeys();
-        for (auto const& key: keys) {
+        for (auto const& key: cur_pages.getKeys()) {
             if ((key == "/MediaBox") || (key == "/CropBox") ||
                 (key == "/Resources") || (key == "/Rotate")) {
                 if (!allow_changes) {
@@ -387,8 +384,7 @@ QPDF::updateObjectMapsInternal(
             }
         }
-        std::set<std::string> keys = dict.getKeys();
-        for (auto const& key: keys) {
+        for (auto const& key: dict.getKeys()) {
             if (is_page_node && (key == "/Thumb")) {
                 // Traverse page thumbnail dictionaries as a special
                 // case.
@@ -437,8 +433,8 @@ QPDF::filterCompressedObjects(std::map&lt;int, int&gt; const&amp; object_stream_data)
     for (auto const& i1: this->m->obj_user_to_objects) {
         ObjUser const& ou = i1.first;
-        std::set<QPDFObjGen> const& objects = i1.second;
-        for (auto const& og: objects) {
+        // Loop over objects.
+        for (auto const& og: i1.second) {
             auto i2 = object_stream_data.find(og.getObj());
             if (i2 == object_stream_data.end()) {
                 t_obj_user_to_objects[ou].insert(og);
@@ -450,8 +446,8 @@ QPDF::filterCompressedObjects(std::map&lt;int, int&gt; const&amp; object_stream_data)
     for (auto const& i1: this->m->object_to_obj_users) {
         QPDFObjGen const& og = i1.first;
-        std::set<ObjUser> const& objusers = i1.second;
-        for (auto const& ou: objusers) {
+        // Loop over obj_users.
+        for (auto const& ou: i1.second) {
             auto i2 = object_stream_data.find(og.getObj());
             if (i2 == object_stream_data.end()) {
                 t_object_to_obj_users[og].insert(ou);
@@ -377,15 +377,12 @@ test_4(QPDF&amp; pdf, char const* arg2)
 static void
 test_5(QPDF& pdf, char const* arg2)
 {
-    QPDFPageDocumentHelper dh(pdf);
-    std::vector<QPDFPageObjectHelper> pages = dh.getAllPages();
     int pageno = 0;
-    for (auto& page: pages) {
+    for (auto& page: QPDFPageDocumentHelper(pdf).getAllPages()) {
         ++pageno;
         std::cout << "page " << pageno << ":" << std::endl;
         std::cout << "  images:" << std::endl;
-        std::map<std::string, QPDFObjectHandle> images = page.getImages();
-        for (auto const& iter2: images) {
+        for (auto const& iter2: page.getImages()) {
             std::string const& name = iter2.first;
             QPDFObjectHandle image = iter2.second;
             QPDFObjectHandle dict = image.getDict();
@@ -1319,9 +1316,7 @@ static void
 test_37(QPDF& pdf, char const* arg2)
 {
     // Parse content streams of all pages
-    std::vector<QPDFPageObjectHelper> pages =
-        QPDFPageDocumentHelper(pdf).getAllPages();
-    for (auto& page: pages) {
+    for (auto& page: QPDFPageDocumentHelper(pdf).getAllPages()) {
         ParserCallbacks cb;
         page.parseContents(&cb);
     }
@@ -1341,10 +1336,8 @@ static void
 test_39(QPDF& pdf, char const* arg2)
 {
     // Display image filter and color set for each image on each page
-    std::vector<QPDFPageObjectHelper> pages =
-        QPDFPageDocumentHelper(pdf).getAllPages();
     int pageno = 0;
-    for (auto& page: pages) {
+    for (auto& page: QPDFPageDocumentHelper(pdf).getAllPages()) {
         std::cout << "page " << ++pageno << std::endl;
         std::map<std::string, QPDFObjectHandle> images = page.getImages();
         for (auto& i_iter: images) {
@@ -1377,9 +1370,7 @@ test_41(QPDF&amp; pdf, char const* arg2)
 {
     // Apply a token filter. This test case is crafted to work
     // with coalesce.pdf.
-    std::vector<QPDFPageObjectHelper> pages =
-        QPDFPageDocumentHelper(pdf).getAllPages();
-    for (auto& page: pages) {
+    for (auto& page: QPDFPageDocumentHelper(pdf).getAllPages()) {
         page.addContentTokenFilter(
             std::shared_ptr<QPDFObjectHandle::TokenFilter>(new TokenFilter()));
     }
@@ -1509,8 +1500,7 @@ test_43(QPDF&amp; pdf, char const* arg2)
         return;
     }
     std::cout << "iterating over form fields\n";
-    std::vector<QPDFFormFieldObjectHelper> form_fields = afdh.getFormFields();
-    for (auto& ffh: form_fields) {
+    for (auto& ffh: afdh.getFormFields()) {
         std::cout << "Field: " << ffh.getObjectHandle().unparse() << std::endl;
         QPDFFormFieldObjectHelper node = ffh;
         while (!node.isNull()) {
@@ -1548,9 +1538,7 @@ test_43(QPDF&amp; pdf, char const* arg2)
     std::cout << "iterating over annotations per page\n";
     for (auto& page: QPDFPageDocumentHelper(pdf).getAllPages()) {
         std::cout << "Page: " << page.getObjectHandle().unparse() << std::endl;
-        std::vector<QPDFAnnotationObjectHelper> annotations =
-            afdh.getWidgetAnnotationsForPage(page);
-        for (auto& ah: annotations) {
+        for (auto& ah: afdh.getWidgetAnnotationsForPage(page)) {
             std::cout << "  Annotation: " << ah.getObjectHandle().unparse()
                       << std::endl;
             std::cout
@@ -1578,9 +1566,7 @@ static void
 test_44(QPDF& pdf, char const* arg2)
 {
     // Set form fields.
-    QPDFAcroFormDocumentHelper afdh(pdf);
-    std::vector<QPDFFormFieldObjectHelper> fields = afdh.getFormFields();
-    for (auto& field: fields) {
+    for (auto& field: QPDFAcroFormDocumentHelper(pdf).getFormFields()) {
         QPDFObjectHandle ft = field.getInheritableFieldValue("/FT");
         if (ft.isName() && (ft.getName() == "/Tx")) {
             // \xc3\xb7 is utf-8 for U+00F7 (divided by)
@@ -51,8 +51,7 @@ walk(
     result[stream_number].push_back(p);
     if (obj.isArray()) {
-        std::vector<QPDFObjectHandle> array = obj.getArrayAsVector();
-        for (auto& oh: array) {
+        for (auto& oh: obj.getArrayAsVector()) {
             if (!oh.isIndirect()) {
                 // QPDF::GetAllObjects() enumerates all indirect objects.
                 // So only the direct objects are recursed here.
@@ -60,8 +59,7 @@ walk(
             }
         }
     } else if (obj.isDictionary()) {
-        std::set<std::string> keys = obj.getKeys();
-        for (auto const& key: keys) {
+        for (auto const& key: obj.getKeys()) {
             QPDFObjectHandle item = obj.getKey(key);
             if (!item.isIndirect()) {
                 // QPDF::GetAllObjects() enumerates all indirect objects.
@@ -81,10 +79,9 @@ process(
 {
     QPDF qpdf;
     qpdf.processFile(fn.c_str());
-    std::vector<QPDFObjectHandle> objs = qpdf.getAllObjects();
     std::map<QPDFObjGen, QPDFXRefEntry> xrefs = qpdf.getXRefTable();
-    for (auto const& oh: objs) {
+    for (auto const& oh: qpdf.getAllObjects()) {
         if (xrefs.count(oh.getObjGen()) == 0) {
             std::cerr << oh.getObjectID() << "/" << oh.getGeneration()
                       << " is not found in xref table" << std::endl;
@@ -26,8 +26,7 @@ main(int argc, char* argv[])
         usage();
     }
     char const* infilename = argv[1];
-    std::list<std::string> lines = QUtil::read_lines_from_file(infilename);
-    for (auto const& line: lines) {
+    for (auto const& line: QUtil::read_lines_from_file(infilename)) {
         QPDFObjectHandle str = QPDFObjectHandle::newString(line);
         std::cout << str.getUTF8Value() << std::endl;
     }
@@ -26,8 +26,7 @@ main(int argc, char* argv[])
         usage();
     }
     char const* infilename = argv[1];
-    std::list<std::string> lines = QUtil::read_lines_from_file(infilename);
-    for (auto const& line: lines) {
+    for (auto const& line: QUtil::read_lines_from_file(infilename)) {
         QPDFObjectHandle str = QPDFObjectHandle::newUnicodeString(line);
         std::cout << str.getUTF8Value() << " // " << str.unparseBinary()
                   << std::endl;
@@ -198,10 +198,8 @@ process(char const* filename, bool include_ignorable, size_t max_len)
     // Tokenize content streams, skipping inline images
     QPDF qpdf;
     qpdf.processFile(filename);
-    std::vector<QPDFPageObjectHelper> pages =
-        QPDFPageDocumentHelper(qpdf).getAllPages();
     int pageno = 0;
-    for (auto& page: pages) {
+    for (auto& page: QPDFPageDocumentHelper(qpdf).getAllPages()) {
         ++pageno;
         Pl_Buffer plb("buffer");
         page.pipeContents(&plb);
@@ -19,9 +19,7 @@ main(int argc, char* argv[])
         QPDF qpdf;
         qpdf.processFile(argv[1]);
-        std::map<QPDFObjGen, QPDFXRefEntry> xref = qpdf.getXRefTable();
-
-        for (auto const& iter: xref) {
+        for (auto const& iter: qpdf.getXRefTable()) {
             std::cout << iter.first.getObj() << "/" << iter.first.getGen()
                       << ", ";
             switch (iter.second.getType()) {