TString Format %s with other TStrings

Hi, I would like to use something like this:

TString s1 = "foo";

However the formatted TString prints as “(null)”. An obvious workaround is to use

but I am wondering why the even-more obvious usage doesn’t work. I know TString::Format is supposed to be the same as the stdlib printf, but I expected TStrings know about other TStrings. Is there a special % format for TStrings?


This is what I would do…

root [0] TString name;
root [1] TString nameAgain = "ICE";
root [2] name.Form("%sHStack%,nameAgain.Data(),i);
end with '}', '@':abort > @
root [3] name.Form("%sHStack%03d",nameAgain.Data(),5);
root [4] printf("%s\n",name.Data());
root [5]