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

Where not possible, use "auto" to get the iterator type.

Editorial note: I have avoid this change for a long time because of
not wanting to make gratuitous changes to version history, which can
obscure when certain changes were made, but with having recently
touched every single file to apply automatic code formatting and with
making several broad changes to the API, I decided it was time to take
the plunge and get rid of the older (pre-C++11) verbose iterator
syntax. The new code is just easier to read and understand, and in
many cases, it will be more effecient as fewer temporary copies are
being made.

m-holger, if you're reading, you can see that I've finally come
around. :-)

1 files changed, 42 insertions, 101 deletions

diff --git a/libqpdf/QPDF_linearization.cc b/libqpdf/QPDF_linearization.cc
index cdeb89a9..ec422406 100644
--- a/libqpdf/QPDF_linearization.cc
+++ b/libqpdf/QPDF_linearization.cc
@@ -583,12 +583,9 @@ QPDF::checkLinearizationInternal()
     // uncompressed.
     { // local scope
         std::map<int, int> object_stream_data;
-        for (std::map<QPDFObjGen, QPDFXRefEntry>::const_iterator iter =
-                 this->m->xref_table.begin();
-             iter != this->m->xref_table.end();
-             ++iter) {
-            QPDFObjGen const& og = (*iter).first;
-            QPDFXRefEntry const& entry = (*iter).second;
+        for (auto const& iter: this->m->xref_table) {
+            QPDFObjGen const& og = iter.first;
+            QPDFXRefEntry const& entry = iter.second;
             if (entry.getType() == 2) {
                 object_stream_data[og.getObj()] = entry.getObjStreamNumber();
             }
@@ -613,10 +610,8 @@ QPDF::checkLinearizationInternal()
     }
     qpdf_offset_t min_E = -1;
     qpdf_offset_t max_E = -1;
-    for (std::vector<QPDFObjectHandle>::iterator iter = this->m->part6.begin();
-         iter != this->m->part6.end();
-         ++iter) {
-        QPDFObjGen og((*iter).getObjGen());
+    for (auto const& oh: this->m->part6) {
+        QPDFObjGen og(oh.getObjGen());
         if (this->m->obj_cache.count(og) == 0) {
             // All objects have to have been dereferenced to be classified.
             throw std::logic_error("linearization part6 object not in cache");
@@ -651,19 +646,15 @@ QPDF::checkLinearizationInternal()
     // code.
     if (!errors.empty()) {
         result = false;
-        for (std::list<std::string>::iterator iter = errors.begin();
-             iter != errors.end();
-             ++iter) {
-            *this->m->err_stream << "WARNING: " << (*iter) << std::endl;
+        for (auto const& error: errors) {
+            *this->m->err_stream << "WARNING: " << error << std::endl;
         }
     }
 
     if (!warnings.empty()) {
         result = false;
-        for (std::list<std::string>::iterator iter = warnings.begin();
-             iter != warnings.end();
-             ++iter) {
-            *this->m->err_stream << "WARNING: " << (*iter) << std::endl;
+        for (auto const& warning: warnings) {
+            *this->m->err_stream << "WARNING: " << warning << std::endl;
         }
     }
 
@@ -678,10 +669,7 @@ QPDF::maxEnd(ObjUser const& ou)
     }
     std::set<QPDFObjGen> const& ogs = this->m->obj_user_to_objects[ou];
     qpdf_offset_t end = 0;
-    for (std::set<QPDFObjGen>::const_iterator iter = ogs.begin();
-         iter != ogs.end();
-         ++iter) {
-        QPDFObjGen const& og = *iter;
+    for (auto const& og: ogs) {
         if (this->m->obj_cache.count(og) == 0) {
             stopOnError("unknown object referenced in object user table");
         }
@@ -855,28 +843,24 @@ QPDF::checkHPageOffset(
             computed_shared.insert(obj);
         }
 
-        for (std::set<int>::iterator iter = hint_shared.begin();
-             iter != hint_shared.end();
-             ++iter) {
-            if (!computed_shared.count(*iter)) {
+        for (int iter: hint_shared) {
+            if (!computed_shared.count(iter)) {
                 // pdlin puts thumbnails here even though it shouldn't
                 warnings.push_back(
                     "page " + QUtil::int_to_string(pageno) +
-                    ": shared object " + QUtil::int_to_string(*iter) +
+                    ": shared object " + QUtil::int_to_string(iter) +
                     ": in hint table but not computed list");
             }
         }
 
-        for (std::set<int>::iterator iter = computed_shared.begin();
-             iter != computed_shared.end();
-             ++iter) {
-            if (!hint_shared.count(*iter)) {
+        for (int iter: computed_shared) {
+            if (!hint_shared.count(iter)) {
                 // Acrobat does not put some things including at least
                 // built-in fonts and procsets here, at least in some
                 // cases.
                 warnings.push_back(
                     "page " + QUtil::int_to_string(pageno) +
-                    ": shared object " + QUtil::int_to_string(*iter) +
+                    ": shared object " + QUtil::int_to_string(iter) +
                     ": in computed list but not hint table");
             }
         }
@@ -1290,13 +1274,9 @@ QPDF::calculateLinearizationData(std::map<int, int> const& object_stream_data)
     std::set<QPDFObjGen> lc_outlines;
     std::set<QPDFObjGen> lc_root;
 
-    for (std::map<QPDFObjGen, std::set<ObjUser>>::iterator oiter =
-             this->m->object_to_obj_users.begin();
-         oiter != this->m->object_to_obj_users.end();
-         ++oiter) {
-        QPDFObjGen const& og = (*oiter).first;
-
-        std::set<ObjUser>& ous = (*oiter).second;
+    for (auto& oiter: this->m->object_to_obj_users) {
+        QPDFObjGen const& og = oiter.first;
+        std::set<ObjUser>& ous = oiter.second;
 
         bool in_open_document = false;
         bool in_first_page = false;
@@ -1306,10 +1286,7 @@ QPDF::calculateLinearizationData(std::map<int, int> const& object_stream_data)
         bool in_outlines = false;
         bool is_root = false;
 
-        for (std::set<ObjUser>::iterator uiter = ous.begin();
-             uiter != ous.end();
-             ++uiter) {
-            ObjUser const& ou = *uiter;
+        for (auto const& ou: ous) {
             switch (ou.ou_type) {
             case ObjUser::ou_trailer_key:
                 if (ou.key == "/Encrypt") {
@@ -1396,11 +1373,8 @@ QPDF::calculateLinearizationData(std::map<int, int> const& object_stream_data)
     { // local scope
         // Map all page objects to the containing object stream.  This
         // should be a no-op in a properly linearized file.
-        std::vector<QPDFObjectHandle> t = getAllPages();
-        for (std::vector<QPDFObjectHandle>::iterator iter = t.begin();
-             iter != t.end();
-             ++iter) {
-            pages.push_back(getUncompressedObject(*iter, object_stream_data));
+        for (auto oh: getAllPages()) {
+            pages.push_back(getUncompressedObject(oh, object_stream_data));
         }
     }
     int npages = toI(pages.size());
@@ -1427,10 +1401,8 @@ QPDF::calculateLinearizationData(std::map<int, int> const& object_stream_data)
                     " calculating linearization data");
     }
     this->m->part4.push_back(objGenToIndirect(*(lc_root.begin())));
-    for (std::set<QPDFObjGen>::iterator iter = lc_open_document.begin();
-         iter != lc_open_document.end();
-         ++iter) {
-        this->m->part4.push_back(objGenToIndirect(*iter));
+    for (auto const& og: lc_open_document) {
+        this->m->part4.push_back(objGenToIndirect(og));
     }
 
     // Part 6: first page objects.  Note: implementation note 124
@@ -1458,16 +1430,12 @@ QPDF::calculateLinearizationData(std::map<int, int> const& object_stream_data)
     // groups private and shared objects contiguously for the sake of
     // hint tables.
 
-    for (std::set<QPDFObjGen>::iterator iter = lc_first_page_private.begin();
-         iter != lc_first_page_private.end();
-         ++iter) {
-        this->m->part6.push_back(objGenToIndirect(*iter));
+    for (auto const& og: lc_first_page_private) {
+        this->m->part6.push_back(objGenToIndirect(og));
     }
 
-    for (std::set<QPDFObjGen>::iterator iter = lc_first_page_shared.begin();
-         iter != lc_first_page_shared.end();
-         ++iter) {
-        this->m->part6.push_back(objGenToIndirect(*iter));
+    for (auto const& og: lc_first_page_shared) {
+        this->m->part6.push_back(objGenToIndirect(og));
     }
 
     // Place the outline dictionary if it goes in the first page section.
@@ -1511,10 +1479,7 @@ QPDF::calculateLinearizationData(std::map<int, int> const& object_stream_data)
                         " calculating linearization data");
         }
         std::set<QPDFObjGen> ogs = this->m->obj_user_to_objects[ou];
-        for (std::set<QPDFObjGen>::iterator iter = ogs.begin();
-             iter != ogs.end();
-             ++iter) {
-            QPDFObjGen const& og = (*iter);
+        for (auto const& og: ogs) {
             if (lc_other_page_private.count(og)) {
                 lc_other_page_private.erase(og);
                 this->m->part7.push_back(objGenToIndirect(og));
@@ -1533,10 +1498,8 @@ QPDF::calculateLinearizationData(std::map<int, int> const& object_stream_data)
     // Part 8: other pages' shared objects
 
     // Order is unimportant.
-    for (std::set<QPDFObjGen>::iterator iter = lc_other_page_shared.begin();
-         iter != lc_other_page_shared.end();
-         ++iter) {
-        this->m->part8.push_back(objGenToIndirect(*iter));
+    for (auto const& og: lc_other_page_shared) {
+        this->m->part8.push_back(objGenToIndirect(og));
     }
 
     // Part 9: other objects
@@ -1555,10 +1518,7 @@ QPDF::calculateLinearizationData(std::map<int, int> const& object_stream_data)
         stopOnError("found empty pages tree while"
                     " calculating linearization data");
     }
-    for (std::set<QPDFObjGen>::iterator iter = pages_ogs.begin();
-         iter != pages_ogs.end();
-         ++iter) {
-        QPDFObjGen const& og = *iter;
+    for (auto const& og: pages_ogs) {
         if (lc_other.count(og)) {
             lc_other.erase(og);
             this->m->part9.push_back(objGenToIndirect(og));
@@ -1588,10 +1548,7 @@ QPDF::calculateLinearizationData(std::map<int, int> const& object_stream_data)
             std::set<QPDFObjGen>& ogs =
                 this->m
                     ->obj_user_to_objects[ObjUser(ObjUser::ou_thumb, toI(i))];
-            for (std::set<QPDFObjGen>::iterator iter = ogs.begin();
-                 iter != ogs.end();
-                 ++iter) {
-                QPDFObjGen const& og = *iter;
+            for (auto const& og: ogs) {
                 if (lc_thumbnail_private.count(og)) {
                     lc_thumbnail_private.erase(og);
                     this->m->part9.push_back(objGenToIndirect(og));
@@ -1606,10 +1563,8 @@ QPDF::calculateLinearizationData(std::map<int, int> const& object_stream_data)
     }
 
     // Place shared thumbnail objects
-    for (std::set<QPDFObjGen>::iterator iter = lc_thumbnail_shared.begin();
-         iter != lc_thumbnail_shared.end();
-         ++iter) {
-        this->m->part9.push_back(objGenToIndirect(*iter));
+    for (auto const& og: lc_thumbnail_shared) {
+        this->m->part9.push_back(objGenToIndirect(og));
     }
 
     // Place outlines unless in first page
@@ -1618,10 +1573,8 @@ QPDF::calculateLinearizationData(std::map<int, int> const& object_stream_data)
     }
 
     // Place all remaining objects
-    for (std::set<QPDFObjGen>::iterator iter = lc_other.begin();
-         iter != lc_other.end();
-         ++iter) {
-        this->m->part9.push_back(objGenToIndirect(*iter));
+    for (auto const& og: lc_other) {
+        this->m->part9.push_back(objGenToIndirect(og));
     }
 
     // Make sure we got everything exactly once.
@@ -1658,10 +1611,7 @@ QPDF::calculateLinearizationData(std::map<int, int> const& object_stream_data)
 
     std::vector<CHSharedObjectEntry>& shared =
         this->m->c_shared_object_data.entries;
-    for (std::vector<QPDFObjectHandle>::iterator iter = this->m->part6.begin();
-         iter != this->m->part6.end();
-         ++iter) {
-        QPDFObjectHandle& oh = *iter;
+    for (auto& oh: this->m->part6) {
         int obj = oh.getObjectID();
         obj_to_index[obj] = toI(shared.size());
         shared.push_back(CHSharedObjectEntry(obj));
@@ -1670,11 +1620,7 @@ QPDF::calculateLinearizationData(std::map<int, int> const& object_stream_data)
     if (!this->m->part8.empty()) {
         this->m->c_shared_object_data.first_shared_obj =
             this->m->part8.at(0).getObjectID();
-        for (std::vector<QPDFObjectHandle>::iterator iter =
-                 this->m->part8.begin();
-             iter != this->m->part8.end();
-             ++iter) {
-            QPDFObjectHandle& oh = *iter;
+        for (auto& oh: this->m->part8) {
             int obj = oh.getObjectID();
             obj_to_index[obj] = toI(shared.size());
             shared.push_back(CHSharedObjectEntry(obj));
@@ -1696,10 +1642,7 @@ QPDF::calculateLinearizationData(std::map<int, int> const& object_stream_data)
                         " calculating linearization data");
         }
         std::set<QPDFObjGen> const& ogs = this->m->obj_user_to_objects[ou];
-        for (std::set<QPDFObjGen>::const_iterator iter = ogs.begin();
-             iter != ogs.end();
-             ++iter) {
-            QPDFObjGen const& og = *iter;
+        for (auto const& og: ogs) {
             if ((this->m->object_to_obj_users[og].size() > 1) &&
                 (obj_to_index.count(og.getObj()) > 0)) {
                 int idx = obj_to_index[og.getObj()];
@@ -1733,10 +1676,8 @@ QPDF::pushOutlinesToPart(
     this->m->c_outline_data.nobjects = 1;
     lc_outlines.erase(outlines_og);
     part.push_back(outlines);
-    for (std::set<QPDFObjGen>::iterator iter = lc_outlines.begin();
-         iter != lc_outlines.end();
-         ++iter) {
-        part.push_back(objGenToIndirect(*iter));
+    for (auto const& og: lc_outlines) {
+        part.push_back(objGenToIndirect(og));
         ++this->m->c_outline_data.nobjects;
     }
 }