use c++11 algorithms to avoid strange compiler warnings

Nobody knows what makes the 'unable to optimize loop' warning to appear
in the sourceslist minus-options parsing, especially if we use a foreach
loop, but we can replace it with some nice c++11 algorithm+lambda usage,
which also helps in making even clearer what happens here.

And as this would be a lonely change, lets do it for a few more loops as
well where I might or might not have seen the warning at some point in
time, too.

Git-Dch: Ignore

4 files changed, 61 insertions, 85 deletions

diff --git a/apt-pkg/aptconfiguration.cc b/apt-pkg/aptconfiguration.cc
index f5bc18394..ed68244c6 100644
--- a/apt-pkg/aptconfiguration.cc
+++ b/apt-pkg/aptconfiguration.cc
@@ -94,11 +94,9 @@ const Configuration::getCompressionTypes(bool const &Cached) {
 			continue;
 		// ignore types we have no app ready to use
 		std::string const app = _config->Find(method);
-		std::vector<APT::Configuration::Compressor>::const_iterator c = compressors.begin();
-		for (; c != compressors.end(); ++c)
-			if (c->Name == app)
-				break;
-		if (c == compressors.end())
+		if (std::find_if(compressors.begin(), compressors.end(), [&app](APT::Configuration::Compressor const &c) {
+				return c.Name == app;
+			}) == compressors.end())
 			continue;
 		types.push_back(*o);
 	}
@@ -115,11 +113,9 @@ const Configuration::getCompressionTypes(bool const &Cached) {
 		if (std::find(types.begin(),types.end(),Types->Tag) != types.end())
 			continue;
 		// ignore types we have no app ready to use
-		std::vector<APT::Configuration::Compressor>::const_iterator c = compressors.begin();
-		for (; c != compressors.end(); ++c)
-			if (c->Name == Types->Value)
-				break;
-		if (c == compressors.end())
+		if (std::find_if(compressors.begin(), compressors.end(), [&Types](APT::Configuration::Compressor const &c) {
+				return c.Name == Types->Value;
+			}) == compressors.end())
 			continue;
 		types.push_back(Types->Tag);
 	}
diff --git a/apt-pkg/cacheset.cc b/apt-pkg/cacheset.cc
index 6a625184e..6b31a4fff 100644
--- a/apt-pkg/cacheset.cc
+++ b/apt-pkg/cacheset.cc
@@ -153,12 +153,8 @@ bool CacheSetHelper::PackageFromRegEx(PackageContainerInterface * const pci, pkg
 			continue;
 		pkgCache::PkgIterator Pkg = Grp.FindPkg(arch);
 		if (Pkg.end() == true) {
-			if (archfound == std::string::npos) {
-				std::vector<std::string> archs = APT::Configuration::getArchitectures();
-				for (std::vector<std::string>::const_iterator a = archs.begin();
-				     a != archs.end() && Pkg.end() != true; ++a)
-					Pkg = Grp.FindPkg(*a);
-			}
+			if (archfound == std::string::npos)
+				Pkg = Grp.FindPreferredPkg(true);
 			if (Pkg.end() == true)
 				continue;
 		}
@@ -213,12 +209,8 @@ bool CacheSetHelper::PackageFromFnmatch(PackageContainerInterface * const pci,
 			continue;
 		pkgCache::PkgIterator Pkg = Grp.FindPkg(arch);
 		if (Pkg.end() == true) {
-			if (archfound == std::string::npos) {
-				std::vector<std::string> archs = APT::Configuration::getArchitectures();
-				for (std::vector<std::string>::const_iterator a = archs.begin();
-				     a != archs.end() && Pkg.end() != true; ++a)
-					Pkg = Grp.FindPkg(*a);
-			}
+			if (archfound == std::string::npos)
+				Pkg = Grp.FindPreferredPkg(true);
 			if (Pkg.end() == true)
 				continue;
 		}
diff --git a/apt-pkg/deb/debmetaindex.cc b/apt-pkg/deb/debmetaindex.cc
index 00dc1eeec..a26b94d82 100644
--- a/apt-pkg/deb/debmetaindex.cc
+++ b/apt-pkg/deb/debmetaindex.cc
@@ -446,10 +446,8 @@ bool debReleaseIndex::GetIndexes(pkgAcquire *Owner, bool const &GetAll)/*{{{*/
 #undef APT_TARGET
    // special case for --print-uris
    if (GetAll)
-   {
-      for (std::vector<IndexTarget>::const_iterator Target = targets.begin(); Target != targets.end(); ++Target)
-	 new pkgAcqIndex(Owner, TransactionManager, *Target);
-   }
+      for (auto const &Target: targets)
+	 new pkgAcqIndex(Owner, TransactionManager, Target);
 
    return true;
 }
@@ -537,17 +535,16 @@ std::vector <pkgIndexFile *> *debReleaseIndex::GetIndexFiles()		/*{{{*/
       return Indexes;
 
    Indexes = new std::vector<pkgIndexFile*>();
-   std::vector<IndexTarget> const Targets = GetIndexTargets();
    bool const istrusted = IsTrusted();
-   for (std::vector<IndexTarget>::const_iterator T = Targets.begin(); T != Targets.end(); ++T)
+   for (auto const &T: GetIndexTargets())
    {
-      std::string const TargetName = T->Option(IndexTarget::CREATED_BY);
+      std::string const TargetName = T.Option(IndexTarget::CREATED_BY);
       if (TargetName == "Packages")
-	 Indexes->push_back(new debPackagesIndex(*T, istrusted));
+	 Indexes->push_back(new debPackagesIndex(T, istrusted));
       else if (TargetName == "Sources")
-	 Indexes->push_back(new debSourcesIndex(*T, istrusted));
+	 Indexes->push_back(new debSourcesIndex(T, istrusted));
       else if (TargetName == "Translations")
-	 Indexes->push_back(new debTranslationsIndex(*T));
+	 Indexes->push_back(new debTranslationsIndex(T));
    }
    return Indexes;
 }
@@ -673,20 +670,17 @@ static std::vector<std::string> parsePlusMinusOptions(std::string const &Name, /
 
    if ((val = Options.find(Name + "+")) != Options.end())
    {
-      std::vector<std::string> const plusArch = VectorizeString(val->second, ',');
-      for (std::vector<std::string>::const_iterator plus = plusArch.begin(); plus != plusArch.end(); ++plus)
-	 if (std::find(Values.begin(), Values.end(), *plus) == Values.end())
-	    Values.push_back(*plus);
+      std::vector<std::string> const plus = VectorizeString(val->second, ',');
+      std::copy_if(plus.begin(), plus.end(), std::back_inserter(Values), [&Values](std::string const &v) {
+	 return std::find(Values.begin(), Values.end(), v) == Values.end();
+      });
    }
    if ((val = Options.find(Name + "-")) != Options.end())
    {
-      std::vector<std::string> const minusArch = VectorizeString(val->second, ',');
-      for (std::vector<std::string>::const_iterator minus = minusArch.begin(); minus != minusArch.end(); ++minus)
-      {
-	 std::vector<std::string>::iterator kill = std::find(Values.begin(), Values.end(), *minus);
-	 if (kill != Values.end())
-	    Values.erase(kill);
-      }
+      std::vector<std::string> const minus = VectorizeString(val->second, ',');
+      Values.erase(std::remove_if(Values.begin(), Values.end(), [&minus](std::string const &v) {
+	 return std::find(minus.begin(), minus.end(), v) != minus.end();
+      }), Values.end());
    }
    return Values;
 }
@@ -743,25 +737,26 @@ class APT_HIDDEN debSLTypeDebian : public pkgSourceList::Type		/*{{{*/
 
       std::vector<std::string> const alltargets = _config->FindVector(std::string("Acquire::IndexTargets::") + Name, "", true);
       std::vector<std::string> mytargets = parsePlusMinusOptions("target", Options, alltargets);
-      if (mytargets.empty() == false)
-	 for (auto const &target : alltargets)
-	 {
-	    std::map<std::string, std::string>::const_iterator const opt = Options.find(target);
-	    if (opt == Options.end())
-	       continue;
-	    auto const tarItr = std::find(mytargets.begin(), mytargets.end(), target);
-	    bool const optValue = StringToBool(opt->second);
-	    if (optValue == true && tarItr == mytargets.end())
-	       mytargets.push_back(target);
-	    else if (optValue == false && tarItr != mytargets.end())
-	       mytargets.erase(std::remove(mytargets.begin(), mytargets.end(), target), mytargets.end());
-	 }
+      for (auto const &target : alltargets)
+      {
+	 std::map<std::string, std::string>::const_iterator const opt = Options.find(target);
+	 if (opt == Options.end())
+	    continue;
+	 auto const tarItr = std::find(mytargets.begin(), mytargets.end(), target);
+	 bool const optValue = StringToBool(opt->second);
+	 if (optValue == true && tarItr == mytargets.end())
+	    mytargets.push_back(target);
+	 else if (optValue == false && tarItr != mytargets.end())
+	    mytargets.erase(std::remove(mytargets.begin(), mytargets.end(), target), mytargets.end());
+      }
+
       bool UsePDiffs = _config->FindB("Acquire::PDiffs", true);
       {
 	 std::map<std::string, std::string>::const_iterator const opt = Options.find("pdiffs");
 	 if (opt != Options.end())
 	    UsePDiffs = StringToBool(opt->second);
       }
+
       Deb->AddComponent(
 	    IsSrc,
 	    Section,
diff --git a/apt-pkg/sourcelist.cc b/apt-pkg/sourcelist.cc
index c0b416820..b083da936 100644
--- a/apt-pkg/sourcelist.cc
+++ b/apt-pkg/sourcelist.cc
@@ -322,7 +322,7 @@ void pkgSourceList::Reset()
 {
    for (const_iterator I = SrcList.begin(); I != SrcList.end(); ++I)
       delete *I;
-   SrcList.erase(SrcList.begin(),SrcList.end());
+   SrcList.clear();
 }
 									/*}}}*/
 // SourceList::Read - Parse the sourcelist file				/*{{{*/
@@ -441,34 +441,26 @@ bool pkgSourceList::ParseFileDeb822(string const &File)
 }
 									/*}}}*/
 // SourceList::FindIndex - Get the index associated with a file		/*{{{*/
-// ---------------------------------------------------------------------
-/* */
+static bool FindInIndexFileContainer(std::vector<pkgIndexFile *> const &Cont, pkgCache::PkgFileIterator const &File, pkgIndexFile *&Found)
+{
+   auto const J = std::find_if(Cont.begin(), Cont.end(), [&File](pkgIndexFile const * const J) {
+	 return J->FindInCache(*File.Cache()) == File;
+   });
+   if (J != Cont.end())
+   {
+      Found = (*J);
+      return true;
+   }
+   return false;
+}
 bool pkgSourceList::FindIndex(pkgCache::PkgFileIterator File,
 			      pkgIndexFile *&Found) const
 {
    for (const_iterator I = SrcList.begin(); I != SrcList.end(); ++I)
-   {
-      vector<pkgIndexFile *> *Indexes = (*I)->GetIndexFiles();
-      for (vector<pkgIndexFile *>::const_iterator J = Indexes->begin();
-	   J != Indexes->end(); ++J)
-      {
-         if ((*J)->FindInCache(*File.Cache()) == File)
-         {
-            Found = (*J);
-            return true;
-         }
-      }
-   }
-   for (vector<pkgIndexFile *>::const_iterator J = VolatileFiles.begin();
-	 J != VolatileFiles.end(); ++J)
-   {
-      if ((*J)->FindInCache(*File.Cache()) == File)
-      {
-	 Found = (*J);
+      if (FindInIndexFileContainer(*(*I)->GetIndexFiles(), File, Found))
 	 return true;
-      }
-   }
-   return false;
+
+   return FindInIndexFileContainer(VolatileFiles, File, Found);
 }
 									/*}}}*/
 // SourceList::GetIndexes - Load the index files into the downloader	/*{{{*/
@@ -517,11 +509,12 @@ time_t pkgSourceList::GetLastModifiedTime()
       List = GetListOfFilesInDir(Parts, "list", true);
 
    // calculate the time
-   time_t mtime_sources = GetModificationTime(Main);
-   for (vector<string>::const_iterator I = List.begin(); I != List.end(); ++I)
-      mtime_sources = std::max(mtime_sources, GetModificationTime(*I));
-
-   return mtime_sources;
+   std::vector<time_t> modtimes;
+   modtimes.reserve(1 + List.size());
+   modtimes.push_back(GetModificationTime(Main));
+   std::transform(List.begin(), List.end(), std::back_inserter(modtimes), GetModificationTime);
+   auto const maxmtime = std::max_element(modtimes.begin(), modtimes.end());
+   return *maxmtime;
 }
 									/*}}}*/
 std::vector<pkgIndexFile*> pkgSourceList::GetVolatileFiles() const	/*{{{*/