Replace 'foo.size() > 0' pattern with !foo.empty().

Source/CPack/IFW/cmCPackIFWGenerator.cxx

@@ -191,7 +191,7 @@ int cmCPackIFWGenerator::PackageFiles()
       }
     }
   // TODO: set correct name for multipackages
-  if (this->packageFileNames.size() > 0)
+  if (!this->packageFileNames.empty())
     {
     ifwCmd += " " + packageFileNames[0];
     }

Source/cmGlobalVisualStudio71Generator.cxx

@@ -250,7 +250,7 @@ void cmGlobalVisualStudio71Generator
     std::set<std::string>::const_iterator it;
     for(it = depends.begin(); it != depends.end(); ++it)
       {
-      if(it->size() > 0)
+      if(!it->empty())
         {
         fout << "\t\t{"
              << this->GetGUID(it->c_str())

Source/cmGlobalVisualStudioGenerator.cxx

@@ -265,7 +265,7 @@ cmGlobalVisualStudioGenerator
         {
         std::vector<std::string> filenames;
         this->GetFilesReplacedDuringGenerate(filenames);
-        if (filenames.size() > 0)
+        if (!filenames.empty())
           {
           // Convert vector to semi-colon delimited string of filenames:
           std::string projects;