TDataFrame ctor does not compile if std::string is passed as filename

std::string fname("f.root");

TDataFrame d("t", fname);

cern762:~$ root -l

 root [0] std::string f("ad")

 (std::string &) "ad"

 root [1] ROOT::Experimental::TDataFrame d("t", f)

 In file included from input_line_11:21:

 In file included from /home/eguiraud/ROOT/root_v610_build/etc/dictpch/allHeaders.h:1139:

 /home/eguiraud/ROOT/root_v610_build/include/ROOT/TDataFrame.hxx:68:52: error: no matching function for call to 'ToConstCharPtr'

 for (auto &fileName : filenamescoll) chain->Add(TDFInternal::ToConstCharPtr(fileName));

 ^~~~~~~~~~~~~~~~~~~~~~~~~~~

 ROOT_prompt_1:1:32: note: in instantiation of function template specialization 'ROOT::Experimental::TDataFrame::TDataFrame<std::__cxx11::basic_string<char>, 0>' requested here

 ROOT::Experimental::TDataFrame d("t", f)

 ^

 /home/eguiraud/ROOT/root_v610_build/include/ROOT/TDFUtils.hxx:190:13: note: candidate function not viable: no known conversion from 'const char' to 'const char *' for 1st argument; take the address of the argument with &

 const char *ToConstCharPtr(const char *s);

 ^

 /home/eguiraud/ROOT/root_v610_build/include/ROOT/TDFUtils.hxx:191:13: note: candidate function not viable: no known conversion from 'const char' to 'const std::string' (aka 'const basic_string<char>') for 1st argument

 const char *ToConstCharPtr(const std::string s);

 ^

 root [2]