Dictionary Not Loading Properly

[cjt00]

Dear Root Authors,

I am trying to read data from a TTree containing a branch filled with vector<map<string, double>>. Here’s a stripped down version of the code I’m using to do it:

void Minimal_Example(std::string infilename){
  
   gInterpreter->GenerateDictionary("vector<map<string,double> >", "vector");
   gSystem->Load("AutoDict_vector_map_string_double____cxx.so");

   // Get trees from file
   TFile *fin = new TFile(infilename.c_str(),"open");
   TTree *tpart = (TTree*)fin->Get("eventweight/ByParticleValidTree_211");

   std::vector<std::map<std::string, double>> *UniverseVals=nullptr;
   tpart->SetBranchAddress("UniverseVals", &UniverseVals);

   tpart->GetEntry(0);

}

Which results in the error:

Error in <TTree::SetBranchAddress>: The class requested (vector<map<string,double> >) for the branch "UniverseVals" is an instance of an stl collection and does not have a compiled CollectionProxy. Please generate the dictionary for this collection (vector<map<string,double> >) to avoid to write corrupted data.

Searching the forum, the solution is supposed to be to generate a dictionary but I’m already doing that in my macro so I’m not sure what else to try here.

Thanks in advance.

Here is the file containing the trees:
trees.root (110.1 KB)

ROOT Version: 6.18/04
Platform: Ubuntu 18.04.5
Compiler: GCC 7.5.0

---

[Wile_E_Coyote]

gSystem->Exec("rm -rf AutoDict*vector*map*string*double*");
gInterpreter->GenerateDictionary("vector<map<string,double> >", "string;map;vector");