TTree::ReadFile and strings


I need to create a root tree reading an ascii file, and I am using the TTree::ReadFile function.

From the documentation I learned that the branch descriptor must be of the form


In particular, it looks like strings are supported too (astring/s).

While with integers, floats, doubles I have no problem and everything works well, when I try to create a string branch I don’t get the expected result.

My code to create and fill the tree:

TTree* eventTree = new  TTree("Mytree", "My Tree");
int nlines = eventTree.ReadFile(fileName);
cout << "Lines read: " << nlines <<endl;

The input file (very simple indeed):

The output of eventTree->Print(); :

Lines read: 0

*Tree :Mytree : My tree *
*Entries : 0 : Total = 913 bytes File Size = 0 *

  •    :          : Tree compression factor =   1.00                       *

*Br 0 :stringvar : stringvar/s *
*Entries : 0 : Total Size= 650 bytes One basket in memory *
*Baskets : 0 : Basket Size= 32000 bytes Compression= 1.00 *


Even an input like

gives the same output from Print().

Could someone tell me which is the correct input format to have string branches work?
Thanks a lot!

Use stringvar/C instead of stringvar/s
This was a typo (now fixed) in the documentation of TTree::ReadFile