cmListCommand: Avoid needlessly erasing from vectors.

The entire vector will be destroyed at once at the end of the scope,
and the remove algorithms already give us the end of the range of
interesting values, so just use those sentinals.

Source/cmListCommand.cxx

@@ -357,13 +357,14 @@ bool cmListCommand
 
   std::vector<std::string> remove(args.begin() + 2, args.end());
   std::sort(remove.begin(), remove.end());
-  remove.erase(std::unique(remove.begin(), remove.end()), remove.end());
-
-  varArgsExpanded.erase(
-      cmRemoveMatching(varArgsExpanded, remove),
-      varArgsExpanded.end());
-
-  std::string value = cmJoin(varArgsExpanded, ";");
+  std::vector<std::string>::const_iterator remEnd =
+      std::unique(remove.begin(), remove.end());
+  std::vector<std::string>::const_iterator remBegin = remove.begin();
+
+  std::vector<std::string>::const_iterator argsEnd =
+      cmRemoveMatching(varArgsExpanded, cmRange(remBegin, remEnd));
+  std::vector<std::string>::const_iterator argsBegin = varArgsExpanded.begin();
+  std::string value = cmJoin(cmRange(argsBegin, argsEnd), ";");
   this->Makefile->AddDefinition(listName, value.c_str());
   return true;
 }
@@ -418,9 +419,11 @@ bool cmListCommand
     return false;
     }
 
-  varArgsExpanded.erase(cmRemoveDuplicates(varArgsExpanded),
-                        varArgsExpanded.end());
-  std::string value = cmJoin(varArgsExpanded, ";");
+  std::vector<std::string>::const_iterator argsEnd =
+      cmRemoveDuplicates(varArgsExpanded);
+  std::vector<std::string>::const_iterator argsBegin =
+      varArgsExpanded.begin();
+  std::string value = cmJoin(cmRange(argsBegin, argsEnd), ";");
 
   this->Makefile->AddDefinition(listName, value.c_str());
   return true;
@@ -503,13 +506,14 @@ bool cmListCommand::HandleRemoveAtCommand(
     }
 
   std::sort(removed.begin(), removed.end());
-  removed.erase(std::unique(removed.begin(), removed.end()), removed.end());
-
-  varArgsExpanded.erase(cmRemoveIndices(varArgsExpanded, removed),
-                        varArgsExpanded.end());
-
-  std::string value = cmJoin(varArgsExpanded, ";");
-
+  std::vector<size_t>::const_iterator remEnd =
+      std::unique(removed.begin(), removed.end());
+  std::vector<size_t>::const_iterator remBegin = removed.begin();
+
+  std::vector<std::string>::const_iterator argsEnd =
+      cmRemoveIndices(varArgsExpanded, cmRange(remBegin, remEnd));
+  std::vector<std::string>::const_iterator argsBegin = varArgsExpanded.begin();
+  std::string value = cmJoin(cmRange(argsBegin, argsEnd), ";");
 
   this->Makefile->AddDefinition(listName, value.c_str());
   return true;