cmAlgorithms: Add cmWrap.

Port some existing cmJoin to use it.

cmJoin is cumbersome to use in cases where the objective is to
somehow 'quote' each item and then join it with a separator.  In that
case, the joiner string is harder to read and reason about.  cmWrap
aims to solve that.

Provide an overload taking char wrappers to simplify the case
of surrounding every element in quotes without needing to escape
the quote character.

Source/cmAlgorithms.h

@@ -278,4 +278,21 @@ typename Range::const_iterator cmRemoveDuplicates(Range& r)
   return cmRemoveIndices(r, indices);
 }
 
+template<typename Range>
+std::string cmWrap(std::string prefix, Range const& r, std::string suffix,
+                   std::string sep)
+{
+  if (r.empty())
+    {
+    return std::string();
+    }
+  return prefix + cmJoin(r, (suffix + sep + prefix).c_str()) + suffix;
+}
+
+template<typename Range>
+std::string cmWrap(char prefix, Range const& r, char suffix, std::string sep)
+{
+  return cmWrap(std::string(1, prefix), r, std::string(1, suffix), sep);
+}
+
 #endif

Source/cmGlobalGenerator.cxx

@@ -2296,14 +2296,7 @@ void cmGlobalGenerator::CreateDefaultGlobalTargets(cmTargets* targets)
       if (!componentsSet->empty())
         {
         ostr << "Available install components are: ";
-        std::set<std::string>::iterator it;
-        for (
-          it = componentsSet->begin();
-          it != componentsSet->end();
-          ++ it )
-          {
-          ostr << " \"" << *it << "\"";
-          }
+        ostr << cmWrap('"', *componentsSet, '"', " ");
         }
       else
         {

Source/cmLocalUnixMakefileGenerator3.cxx

@@ -724,12 +724,7 @@ cmLocalUnixMakefileGenerator3
     }
 
   // Write the list of commands.
-  for(std::vector<std::string>::const_iterator i = commands.begin();
-      i != commands.end(); ++i)
-    {
-    replace = *i;
-    os << "\t" << replace << "\n";
-    }
+  os << cmWrap("\t", commands, "", "\n") << "\n";
   if(symbolic && !this->WatcomWMake)
     {
     os << ".PHONY : " << cmMakeSafe(tgt) << "\n";

Source/cmSystemTools.cxx

@@ -835,7 +835,7 @@ cmSystemTools::PrintSingleCommand(std::vector<std::string> const& command)
     return std::string();
     }
 
-  return "\"" + cmJoin(command, "\" \"") + "\"";
+  return cmWrap('"', command, '"', " ");
 }
 
 bool cmSystemTools::DoesFileExistWithExtensions(

Source/cmcmd.cxx

@@ -450,9 +450,7 @@ int cmcmd::ExecuteCMakeCommand(std::vector<std::string>& args)
         return 1;
         }
 
-      std::string command = "\"";
-      command += cmJoin(cmRange(args).advance(3), "\" \"");
-      command += "\"";
+      std::string command = cmWrap('"', cmRange(args).advance(3), '"', " ");
       int retval = 0;
       int timeout = 0;
       if ( cmSystemTools::RunSingleCommand(command.c_str(), 0, &retval,