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, 36 insertions, 83 deletions

diff --git a/libqpdf/QPDF.cc b/libqpdf/QPDF.cc
index bab30042..815894d3 100644
--- a/libqpdf/QPDF.cc
+++ b/libqpdf/QPDF.cc
@@ -262,11 +262,8 @@ QPDF::~QPDF()
     // have the effect of undoing any modifications that may have been
     // made to any of the objects.
     this->m->xref_table.clear();
-    for (std::map<QPDFObjGen, ObjCache>::iterator iter =
-             this->m->obj_cache.begin();
-         iter != this->m->obj_cache.end();
-         ++iter) {
-        QPDFObject::ObjAccessor::releaseResolved((*iter).second.object.get());
+    for (auto const& iter: this->m->obj_cache) {
+        QPDFObject::ObjAccessor::releaseResolved(iter.second.object.get());
     }
 }
 
@@ -577,18 +574,13 @@ QPDF::reconstruct_xref(QPDFExc& e)
 
     // Delete all references to type 1 (uncompressed) objects
     std::set<QPDFObjGen> to_delete;
-    for (std::map<QPDFObjGen, QPDFXRefEntry>::iterator iter =
-             this->m->xref_table.begin();
-         iter != this->m->xref_table.end();
-         ++iter) {
-        if (((*iter).second).getType() == 1) {
-            to_delete.insert((*iter).first);
+    for (auto const& iter: this->m->xref_table) {
+        if (iter.second.getType() == 1) {
+            to_delete.insert(iter.first);
         }
     }
-    for (std::set<QPDFObjGen>::iterator iter = to_delete.begin();
-         iter != to_delete.end();
-         ++iter) {
-        this->m->xref_table.erase(*iter);
+    for (auto const& iter: to_delete) {
+        this->m->xref_table.erase(iter);
     }
 
     this->m->file->seek(0, SEEK_END);
@@ -1015,10 +1007,7 @@ QPDF::read_xrefTable(qpdf_offset_t xref_offset)
     }
 
     // Handle any deleted items now that we've read the /XRefStm.
-    for (std::vector<QPDFObjGen>::iterator iter = deleted_items.begin();
-         iter != deleted_items.end();
-         ++iter) {
-        QPDFObjGen& og = *iter;
+    for (auto const& og: deleted_items) {
         insertXrefEntry(og.getObj(), 0, 0, og.getGen());
     }
 
@@ -1351,12 +1340,9 @@ QPDF::insertXrefEntry(int obj, int f0, qpdf_offset_t f1, int f2, bool overwrite)
 void
 QPDF::showXRefTable()
 {
-    for (std::map<QPDFObjGen, QPDFXRefEntry>::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;
         *this->m->out_stream << og.getObj() << "/" << og.getGen() << ": ";
         switch (entry.getType()) {
         case 1:
@@ -1390,27 +1376,19 @@ QPDF::fixDanglingReferences(bool force)
     // Create a set of all known indirect objects including those
     // we've previously resolved and those that we have created.
     std::set<QPDFObjGen> to_process;
-    for (std::map<QPDFObjGen, ObjCache>::iterator iter =
-             this->m->obj_cache.begin();
-         iter != this->m->obj_cache.end();
-         ++iter) {
-        to_process.insert((*iter).first);
+    for (auto const& iter: this->m->obj_cache) {
+        to_process.insert(iter.first);
     }
-    for (std::map<QPDFObjGen, QPDFXRefEntry>::iterator iter =
-             this->m->xref_table.begin();
-         iter != this->m->xref_table.end();
-         ++iter) {
-        to_process.insert((*iter).first);
+    for (auto const& iter: this->m->xref_table) {
+        to_process.insert(iter.first);
     }
 
     // For each non-scalar item to process, put it in the queue.
     std::list<QPDFObjectHandle> queue;
     queue.push_back(this->m->trailer);
-    for (std::set<QPDFObjGen>::iterator iter = to_process.begin();
-         iter != to_process.end();
-         ++iter) {
+    for (auto const& iter: to_process) {
         QPDFObjectHandle obj = QPDFObjectHandle::Factory::newIndirect(
-            this, (*iter).getObj(), (*iter).getGen());
+            this, iter.getObj(), iter.getGen());
         if (obj.isDictionary() || obj.isArray()) {
             queue.push_back(obj);
         } else if (obj.isStream()) {
@@ -1428,21 +1406,15 @@ QPDF::fixDanglingReferences(bool force)
         if (obj.isDictionary()) {
             std::map<std::string, QPDFObjectHandle> members =
                 obj.getDictAsMap();
-            for (std::map<std::string, QPDFObjectHandle>::iterator iter =
-                     members.begin();
-                 iter != members.end();
-                 ++iter) {
-                to_check.push_back((*iter).second);
+            for (auto const& iter: members) {
+                to_check.push_back(iter.second);
             }
         } else if (obj.isArray()) {
             QPDF_Array* arr = dynamic_cast<QPDF_Array*>(
                 QPDFObjectHandle::ObjAccessor::getObject(obj).get());
             arr->addExplicitElementsToList(to_check);
         }
-        for (std::list<QPDFObjectHandle>::iterator iter = to_check.begin();
-             iter != to_check.end();
-             ++iter) {
-            QPDFObjectHandle sub = *iter;
+        for (auto sub: to_check) {
             if (sub.isIndirect()) {
                 if (sub.getOwningQPDF() == this) {
                     QPDFObjGen og(sub.getObjGen());
@@ -1480,11 +1452,8 @@ QPDF::getAllObjects()
     // object cache.
     fixDanglingReferences(true);
     std::vector<QPDFObjectHandle> result;
-    for (std::map<QPDFObjGen, ObjCache>::iterator iter =
-             this->m->obj_cache.begin();
-         iter != this->m->obj_cache.end();
-         ++iter) {
-        QPDFObjGen const& og = (*iter).first;
+    for (auto const& iter: this->m->obj_cache) {
+        QPDFObjGen const& og = iter.first;
         result.push_back(
             // line-break
             QPDFObjectHandle::Factory::newIndirect(
@@ -1733,12 +1702,9 @@ QPDF::recoverStreamLength(
         QPDFObjGen this_obj(0, 0);
 
         // Make sure this is inside this object
-        for (std::map<QPDFObjGen, QPDFXRefEntry>::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() == 1) {
                 qpdf_offset_t obj_offset = entry.getOffset();
                 if ((obj_offset > stream_offset) &&
@@ -2157,15 +2123,13 @@ QPDF::resolveObjectsInStream(int obj_stream_number)
     // that some objects stored here might have been overridden by new
     // objects appended to the file, so it is necessary to recheck the
     // xref table and only cache what would actually be resolved here.
-    for (std::map<int, int>::iterator iter = offsets.begin();
-         iter != offsets.end();
-         ++iter) {
-        int obj = (*iter).first;
+    for (auto const& iter: offsets) {
+        int obj = iter.first;
         QPDFObjGen og(obj, 0);
         QPDFXRefEntry const& entry = this->m->xref_table[og];
         if ((entry.getType() == 2) &&
             (entry.getObjStreamNumber() == obj_stream_number)) {
-            int offset = (*iter).second;
+            int offset = iter.second;
             input->seek(offset, SEEK_SET);
             QPDFObjectHandle oh = readObject(input, "", obj, 0, true);
             this->m->obj_cache[og] = ObjCache(
@@ -2317,11 +2281,7 @@ QPDF::copyForeignObject(QPDFObjectHandle foreign)
     }
 
     // Copy any new objects and replace the reservations.
-    for (std::vector<QPDFObjectHandle>::iterator iter =
-             obj_copier.to_copy.begin();
-         iter != obj_copier.to_copy.end();
-         ++iter) {
-        QPDFObjectHandle& to_copy = *iter;
+    for (auto& to_copy: obj_copier.to_copy) {
         QPDFObjectHandle copy =
             replaceForeignIndirectObjects(to_copy, obj_copier, true);
         if (!to_copy.isStream()) {
@@ -2365,8 +2325,7 @@ QPDF::reserveObjects(QPDFObjectHandle foreign, ObjCopier& obj_copier, bool top)
         }
         QTC::TC("qpdf", "QPDF copy indirect");
         obj_copier.visiting.insert(foreign_og);
-        std::map<QPDFObjGen, QPDFObjectHandle>::iterator mapping =
-            obj_copier.object_map.find(foreign_og);
+        auto mapping = obj_copier.object_map.find(foreign_og);
         if (mapping == obj_copier.object_map.end()) {
             obj_copier.to_copy.push_back(foreign);
             QPDFObjectHandle reservation;
@@ -2388,10 +2347,8 @@ QPDF::reserveObjects(QPDFObjectHandle foreign, ObjCopier& obj_copier, bool top)
     } else if (foreign.isDictionary()) {
         QTC::TC("qpdf", "QPDF reserve dictionary");
         std::set<std::string> keys = foreign.getKeys();
-        for (std::set<std::string>::iterator iter = keys.begin();
-             iter != keys.end();
-             ++iter) {
-            reserveObjects(foreign.getKey(*iter), obj_copier, false);
+        for (auto const& key: keys) {
+            reserveObjects(foreign.getKey(key), obj_copier, false);
         }
     } else if (foreign.isStream()) {
         QTC::TC("qpdf", "QPDF reserve stream");
@@ -2412,8 +2369,7 @@ QPDF::replaceForeignIndirectObjects(
     if ((!top) && foreign.isIndirect()) {
         QTC::TC("qpdf", "QPDF replace indirect");
         QPDFObjGen foreign_og(foreign.getObjGen());
-        std::map<QPDFObjGen, QPDFObjectHandle>::iterator mapping =
-            obj_copier.object_map.find(foreign_og);
+        auto mapping = obj_copier.object_map.find(foreign_og);
         if (mapping == obj_copier.object_map.end()) {
             // This case would occur if this is a reference to a Page
             // or Pages object that we didn't traverse into.
@@ -2657,12 +2613,9 @@ QPDF::getXRefTable()
 void
 QPDF::getObjectStreamData(std::map<int, int>& omap)
 {
-    for (std::map<QPDFObjGen, QPDFXRefEntry>::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) {
             omap[og.getObj()] = entry.getObjStreamNumber();
         }